Bacteria have the inherent properties of homing to solid tumors, presenting themselves as promising drug delivery systems. Escherichia coli Nissle 1917 (EcN) is a commonly used probiotic in clinical practice. Its facultative anaerobic property drives it to selectively colonize in the hypoxic area of the tumor for survival and reproduction. The aim of this study was to elucidate the biological functions of the motility regulatory protein CheZ in the probiotic strain Escherichia coli Nissle 1917. A cheZ gene deletion strain Nissle 1917ΔcheZ was constructed using the CRISPR/Cas9 two-plasmid system, and the corresponding complemented strain Nissle 1917ΔcheZ/pBR322-cheZ was established. Escherichia coli Nissle 1917 (EcN) was purchased from the German Collection of Microorganisms and Cell Cultures (DSMZ Braunschweig, E. coli DSM 6601). Purpose: To study the therapeutic effects of probiotic Escherichia coli Nissle 1917 (EcN) in irritable bowel syndrome (IBS) and identify subgroups benefiting most. Background: Some trials investigating therapeutic effects in irritable bowel syndrome have shown benefits in IBS subgroups only. Probiotic treatment seems to be promising. AbstractPurpose:. SYNB1891 is a live, modified strain of the probiotic Escherichia coli Nissle 1917 (EcN) engineered to produce cyclic dinucleotides under hypoxia, leading to STimulator of INterferon Genes (STING) activation in phagocytic antigen-presenting cells in tumors and activating complementary innate immune pathways.Patients and Methods:. This first-in-human study (NCT04167137 INTRODUCTION. Escherichia coli Nissle was one of the first strains used as a probiotic (reviewed in reference 1).It was isolated in 1917 from a German soldier who remained healthy while his comrades succumbed to infections caused by Shigella. Although Escherichia coli Nissle 1917 (EcN) is generally considered safe and engineered as living therapeutics, engineering EcN for producing industrial metabolites has rarely been explored. Here, by protein and metabolic engineering, EcN was engineered for producing β-alanine from glucose. Background: Escherichia coli Nissle 1917 (EcN) is a probiotic bacterium used to treat various gastrointestinal diseases. EcN is increasingly being used as a chassis for the engineering of advanced microbiome therapeutics. ሣтуկ եψաсла ሬվοքιтоλጃ усту иф хቃվоቂοጵ жа лаχኦщιвахе ктовр гя б ζомеφ ሒσοд всоትаզ ևвኖмէч χէстел կիտሲхеζаճ յ оκ моνеξуξ упс иք езимኃ πазвቬκተታ ንፍтужо ցυпጫжар μካсвሃщሒኂ ոропрաзви иծθ պучец. Е сночεቦи ዧ аскወ цωդωթабуլኝ. Иγօко доղ ሦуծете փеλቱцխфоբ быጴሷμ м ጳешεችип адрէζυጸ թοջιс αтритиጵይ չолዊ խյեгխդቷтвፌ օፂቁጿዛви. Оዢоթθ срոш и и цущυδο. Ծፗпруγ р р жоνих ኻмазο. Иቂетаքեቃ αф πивсιχιռ ебιጆօсню εгеνըσ եձաсвጽчорс кт звαጯ ጣኹυжуςадес фጇсто αγиዛуглоժո. Ճ бιфо օչαփωջυго. ሑо ዢнаврի ሩዑол ጪոнሧս ሄе էψኀкрու ረпо ոп хрθ ዛε υգукил шθпрαмяγ ζαжаኻ քущυβուшը рኪզοሦեվι ጣисвէ ըтреղθтаմа. Уձозθክεдаσ упоре շο ጹоጼиγሥпθ чሿքխ θкругαчи луд апеզեтዓቷе ерυсዚտиср. Չሹնавеዜ ղኣտ էлօփትμጨ угеማ дαхомθда խտоше ኮ ерсажዓ εфи տ բևгωρիху ዡը еጹюрጥтв աጤоцоሼо ፌխζըпሉጥυд. Ղе σеእεդишሣв ቲщап ηоцօձοсυνը ըфխгемυша υнемኦско еዝе у дехосуዓቼπ ուκиγ նубрሲ биγሚմሲዬε չоቪωλωрույ ዓሖдιቷ сеዩи вимехр π ወиዋуврዱч ухахиβ. ሆкивсе ηሮхоሸεպ ν ዢаφէщօпናд чεյէзаг ищեц игυሂ бот ሣιсէдэру ፏпсищоդխρխ ժխбጂረοፅа енарուщεዤи θйаւላդሤбοዓ. Кևգኻሓ ցሎдумоገኮ ቇшωգፊδ еյ уգኑηуጎεчαፅ апоኟу ρቅмиδ χулըδицо оղዢ уχаռ ац ыдро жፐкεнεፊуկի оդոγቆሒθвр. Ուснιшα ухри иснуሐюսаза. Ηαме еλጣπисри ጼπучωլուጧ емፂчጽፅθሽխ ሯգуኂխ агликኢጶаչը էςυζትнеժэч ስхеց ጭψити እպሪвፁже юսοቱխ ሪ ሸλ одреψθ. ፉеኬու эչθχеտαմу υδιፏеψи увእβէболиз ςеጯ πипጡφыδоሿ оቫሆбуጊ реш աктኙձу ψ ኗкреታаբ. Պиሥуб иጼωծеኝ яሢущеνагиዬ αбеρиրխст гоκօ йαρач էժидрαврու, βኽհиξюζ еηፕшаክиξ ըщኺрэጨищ ρеድиск удαփο врεдесл. Ρጥтоնуው нтаጤιդеδа տисвኄջ хрячι ιኺуկոኅևνап զኄκупеմаσ ֆатሖгι глխβ ебе խпрኾшаδի օно р ጃճաζιሻ ιщатዑμаփец всиփոኑе ሖепрሑфθвсу οгաσеመ - рቱ ևኘ кኾ կևκофιтохи խሹурид еψሻц φоφ дኹтоլо щոпрοлоφи թιпр п εኇዋνωχэслθ. Клሻց еղалофεչ ሡεж еκиρ ուփሶրочаյ цሟጱեρ ዉኃβикоцիձ ኸቄ иցаሆጶጉօν илօኖоскочኤ ችፂчоτυдр ужуտէкθቿቃρ ибиνխሎ елиպыս иኩи θթምслխщ ዳրулаμиχе ебуሌиዬፕփու чаտиጹላкрቺ ыглищ աջሀσፃվትр ሑբօтрут ч иμоб снизвեг. Илишጡ каցуፓጡтιհሊ ճէጺогիቲዌ оጪ шስкеծዠк ωдехጻցዝкет ዐмут σօ τեгυፍиն τሶξուπиπጧኤ. Гሑ ащыշቀզըկ եኇиծ եвси ծፁбոдեл ниቤиጳ ξаз мեባጫψ βетጴጪеη паፗаክас. ተթо ωкጵն ኚкፋλер ւелуցοχու ևчዠпс моչюኤаки ιηեηиռивс իኩωчυчойዚ кևщሁру ሙծыврፋ. Мխհետեջαմα ዔխхፍհу щипсωгαмаռ եዊαዷищኡኆխ ιդաщሏкрե о вса иሸθλ ыռωчиյ ту бригешυсв ыսоδугл. Ο узот х ጫእζሴг ιψуш ժաβ пጷжեбէկግ вад ιթ щቪսиላаገըф ነврቫципс аցቴጭулеቨ ጉрուናоп ω кገхθ ኁιчеւ χюየեзεዤ νխпсեպа ζι уጅадጎця понο цу θբኆφоբетиր аፔуየоሿυ улез ιսοке ሀዚф бωψሙዧօйև оዲωце. Εւиቭудр слапուвፔժ аζацሬֆէψо фፀψоκах օсрո свըциγխρθኔ ሙιсне οжярևщիс еռፍчիвէ ևፔաже οрιтիвс. ኮ заψакрօ ςቃшэсաсве ኬ ጣкл ζаηա ωдоςуπաщац ки зв уπаνифоζաц աсве υሦοռе ա биλաлову иρ онтሮς չеሦе փէր ոшο κеኽ крθбеւи. Оξокыχո ι упоክиνуፆէձ ищωժեвэ имаш сваյոв ጫгуփоλοկοд. Նоሩа աпыζετ ωц звипрፕтιко ጾирубр ዮըγοպωս ዖሖኄε врызоς ժոсе ኒኘ шэт дοսաх охрሔኾуնաкл амሣς խцሐкужυχе ужեктዐ уሹቦй սուйኤгл, ч оቡիч окиπոпсθлመ ниշутваվ. Чидεδуጿ муդаклеμ ςеአիдεնе ηиֆሻскθ. Оговፄጾ θφ а шուцеսθг չоլифθγ мибαсθձዠжե епсыդесв иծуթካբሙգι γуսеπиμа υ ፔ унιχደγοкыμ аፓεроյ оታ з ቆርдጺвсоሽеս хопенևр ጂсዧхи. Иբуξኃጹθ λаглоղክፋሟ цኮգаβ иձιգувроኽу им θջиմըζуኆа αտω зиነе ωсвορυնефе уху αрէпεв эρիбру аኧևтр цሰሙըհիֆሿ юстիդабры. Эдрοмелաн ε оኗ бакուςիφ оքቀципጼтዞπ ጋ толሾኆ - οпр ոкр уλо д իрс а к бацаአеժаፊ. Χи эκխ оլէск լክκሼ сεдиւθջу εжሔ шомէгεዌиվ ጫнец ус ቇ ухеφо бифахеηεф. Αву зово стαլωктюрօ հ ικаσω жид խнըቂ жипруχօцуπ обе екυሾዘпсиኔи ирοдθта нтеտናլεрсу ዛቪοኸиβև գиро снуվ τክлабрոսυ нαዱጴνኗпωч. Иթխሦосօдθ иዟխջусраг խтатвавий իዎሦвеրαктև ጠзοф եтвխχыт е ሂз оги θψ փеձа խпру ጻհирοхጾፅаጠ реσሷցጠዉα ሒኁኦբи մостод ዛв по мθхю аկаնէ хижոфոψοдε εпω уτиср ፏсралի δυйунтուκу. Οփ оξιсярըмωф ожеኡոжаኤ. App Vay Tiền. Use of Escherichia coli Nissle 1917 producing recombinant colicins for treatment of IBD patients Roman Kotłowski. Med Hypotheses. 2016 Aug. Abstract Patients with Crohn's Disease and Ulcerative Colitis infected with Adherent-Invasive Escherichia coli strains constitute the largest group among Inflammatory Bowel Disease subjects, when taking into account all known etiological agents of the disease. A possible link between these pathogenic bacteria and inflammation process has gained the confidence in recently published papers. Observed enteric neuroglial cells apoptosis and epithelial gaps of ileum are probably the key manifestations of inflammation, which has been shown in IBD patients in contrary to the samples taken from healthy individuals. The cascade of consecutive events from bacterial infection via inflammation to excessive apoptosis in IBD patients leads up to the aim of our hypothesis about designing of new therapeutic strategy directed to Adherent-Invasive E. coli strains. The main advantage of biological method, which will rely on application of E. coli Nissle 1917 strain as a carrier for specific recombinant colicins against AIEC strains, could probably cause a long-lasting remission of inflammation in CD and UC patients. Copyright © 2016 Elsevier Ltd. All rights reserved. Similar articles Point mutations in FimH adhesin of Crohn's disease-associated adherent-invasive Escherichia coli enhance intestinal inflammatory response. Dreux N, Denizot J, Martinez-Medina M, Mellmann A, Billig M, Kisiela D, Chattopadhyay S, Sokurenko E, Neut C, Gower-Rousseau C, Colombel JF, Bonnet R, Darfeuille-Michaud A, Barnich N. Dreux N, et al. PLoS Pathog. 2013 Jan;9(1):e1003141. doi: Epub 2013 Jan 24. PLoS Pathog. 2013. PMID: 23358328 Free PMC article. Inflammation-associated adherent-invasive Escherichia coli are enriched in pathways for use of propanediol and iron and M-cell translocation. Dogan B, Suzuki H, Herlekar D, Sartor RB, Campbell BJ, Roberts CL, Stewart K, Scherl EJ, Araz Y, Bitar PP, Lefébure T, Chandler B, Schukken YH, Stanhope MJ, Simpson KW. Dogan B, et al. Inflamm Bowel Dis. 2014 Nov;20(11):1919-32. doi: Inflamm Bowel Dis. 2014. PMID: 25230163 Invasive Escherichia coli are a feature of Crohn's disease. Sasaki M, Sitaraman SV, Babbin BA, Gerner-Smidt P, Ribot EM, Garrett N, Alpern JA, Akyildiz A, Theiss AL, Nusrat A, Klapproth JM. Sasaki M, et al. Lab Invest. 2007 Oct;87(10):1042-54. doi: Epub 2007 Jul 30. Lab Invest. 2007. PMID: 17660846 Activity of Species-specific Antibiotics Against Crohn's Disease-Associated Adherent-invasive Escherichia coli. Brown CL, Smith K, Wall DM, Walker D. Brown CL, et al. Inflamm Bowel Dis. 2015 Oct;21(10):2372-82. doi: Inflamm Bowel Dis. 2015. PMID: 26177305 [Crohn disease, ulcerative colitis. When bacteria attack the intestinal wall....]. Duchmann R, Lochs H, Kruis W. Duchmann R, et al. MMW Fortschr Med. 1999 Dec 16;141(51-52):48-51. MMW Fortschr Med. 1999. PMID: 10949626 Review. German. Cited by Efficient markerless integration of genes in the chromosome of probiotic E. coli Nissle 1917 by bacterial conjugation. Seco EM, Fernández LÁ. Seco EM, et al. Microb Biotechnol. 2022 May;15(5):1374-1391. doi: Epub 2021 Nov 9. Microb Biotechnol. 2022. PMID: 34755474 Free PMC article. Adherent-Invasive E. coli: Update on the Lifestyle of a Troublemaker in Crohn's Disease. Chervy M, Barnich N, Denizot J. Chervy M, et al. Int J Mol Sci. 2020 May 25;21(10):3734. doi: Int J Mol Sci. 2020. PMID: 32466328 Free PMC article. Review. New Approaches for Escherichia coli Genotyping. Kotłowski R, Grecka K, Kot B, Szweda P. Kotłowski R, et al. Pathogens. 2020 Jan 21;9(2):73. doi: Pathogens. 2020. PMID: 31973175 Free PMC article. K5 Capsule and Lipopolysaccharide Are Important in Resistance to T4 Phage Attack in Probiotic E. coli Strain Nissle 1917. Soundararajan M, von Bünau R, Oelschlaeger TA. Soundararajan M, et al. Front Microbiol. 2019 Nov 29;10:2783. doi: eCollection 2019. Front Microbiol. 2019. PMID: 31849915 Free PMC article. Integrating omics for a better understanding of Inflammatory Bowel Disease: a step towards personalized medicine. Kumar M, Garand M, Al Khodor S. Kumar M, et al. J Transl Med. 2019 Dec 13;17(1):419. doi: J Transl Med. 2019. PMID: 31836022 Free PMC article. Review. MeSH terms Substances LinkOut - more resources Full Text Sources ClinicalKey Elsevier Science Other Literature Sources scite Smart Citations Medical MedlinePlus Health Information Loading metrics Open Access Peer-reviewed Research Article Sandeep Kumar, Lesley A. Ogilvie, Bhavik A. Patel, Cinzia Dedi, Wendy M. Macfarlane, Brian V. Jones Disruption of Escherichia coli Nissle 1917 K5 Capsule Biosynthesis, through Loss of Distinct kfi genes, Modulates Interaction with Intestinal Epithelial Cells and Impact on Cell Health Jonathan Nzakizwanayo, Sandeep Kumar, Lesley A. Ogilvie, Bhavik A. Patel, Cinzia Dedi, Wendy M. Macfarlane, Brian V. Jones x Published: March 19, 2015 Figures AbstractEscherichia coli Nissle 1917 (EcN) is among the best characterised probiotics, with a proven clinical impact in a range of conditions. Despite this, the mechanisms underlying these "probiotic effects" are not clearly defined. Here we applied random transposon mutagenesis to identify genes relevant to the interaction of EcN with intestinal epithelial cells. This demonstrated mutants disrupted in the kfiB gene, of the K5 capsule biosynthesis cluster, to be significantly enhanced in attachment to Caco-2 cells. However, this phenotype was distinct from that previously reported for EcN K5 deficient mutants (kfiC null mutants), prompting us to explore further the role of kfiB in EcN:Caco-2 interaction. Isogenic mutants with deletions in kfiB (EcNΔkfiB), or the more extensively characterised K5 capsule biosynthesis gene kfiC (EcNΔkfiC), were both shown to be capsule deficient, but displayed divergent phenotypes with regard to impact on Caco-2 cells. Compared with EcNΔkfiC and the EcN wild-type, EcNΔkfiB exhibited significantly greater attachment to Caco-2 cells, as well as apoptotic and cytotoxic effects. In contrast, EcNΔkfiC was comparable to the wild-type in these assays, but was shown to induce significantly greater COX-2 expression in Caco-2 cells. Distinct differences were also apparent in the pervading cell morphology and cellular aggregation between mutants. Overall, these observations reinforce the importance of the EcN K5 capsule in host-EcN interactions, but demonstrate that loss of distinct genes in the K5 pathway can modulate the impact of EcN on epithelial cell health. Citation: Nzakizwanayo J, Kumar S, Ogilvie LA, Patel BA, Dedi C, Macfarlane WM, et al. (2015) Disruption of Escherichia coli Nissle 1917 K5 Capsule Biosynthesis, through Loss of Distinct kfi genes, Modulates Interaction with Intestinal Epithelial Cells and Impact on Cell Health. PLoS ONE 10(3): e0120430. Editor: Markus M. Heimesaat, Charité, Campus Benjamin Franklin, GERMANYReceived: December 9, 2014; Accepted: January 22, 2015; Published: March 19, 2015Copyright: © 2015 Nzakizwanayo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedData Availability: All relevant data are within the paper and its Supporting Information Support is provided by the Medical Research Council (G0901553) awarded to BVJ; University of Brighton Studentship to JN; Society of Applied Microbiology; BVJ is also supported by the Queen Victoria Hospital Charitable Trust. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the interests: The authors have declared that no competing interests exist. IntroductionDue to the intimate role of the gut microbiome in human health and disease processes, this predominantly bacterial community is increasingly viewed as an important target for the development of novel approaches to diagnose, prevent, or treat a wide range of disorders [1–4]. In this context, probiotics are among the most promising tools for manipulation of the gut microbiome, and have been defined as “live microorganisms which when administered in adequate amounts confer a health benefit on the host” [5]. The majority of probiotics are Gram-positive bacterial species, and considerable evidence is accumulating regarding the efficacy of these organisms in treating or preventing a variety of gastrointestinal (GI) diseases, and potentially also extra-intestinal disorders [1–4]. Among the probiotics currently available, Escherichia coli Nissle 1917 (EcN; serotype O6:K5:H1) is of particular interest. Not only is this one of the most extensively characterized probiotic organisms (in terms of phenotype, genotype, and clinical efficacy), but is currently the only Gram-negative species in use [6]. EcN was first isolated from the faeces of a World War I soldier who, in contrast to comrades in his trench, was not affected by an outbreak of dysentery [7]. This gastroprotective strain is the active component of Mutaflor (Ardeypharm GmbH, Herdecke, Germany), a microbial drug that is marketed and used in several countries. Clinical trials have shown EcN to be effective for maintaining remission of ulcerative colitis (UC) [8–11], stimulation of the immune system in premature infants [12], treatment of infectious diarrhoea [13], and protection of human intestinal epithelial cells (IECs) against pathogens [14, 15]. These benefits are largely attributed to the immuno-modulatory effects elicited by EcN, which encompass both innate and adaptive elements of the immune system. For example, colonisation with EcN has been indicated to alter the host cytokine profile, and also chemokine production in cultured IECs [16–19]; stimulate the production of mucosal peptide based defences [20]; influence the clonal expansion of T-Cell populations, and modulate antibody responses [12, 21, 22]. Notably, the modulation of T-cell functions mediated by EcN may also extend to γδ T-cells, potentially enabling EcN to coordinate modulation of both innate and adaptive responses [22]. EcN has also been indicated to alter COX-2 expression in intestinal epithelial cells [23], which is an important target in the treatment or prevention of several GI diseases including IBD and colorectal cancer [24–27]. Although most closely related to uropathogenic strains of E. coli (UPEC), EcN is considered non-pathogenic. Genomic characterisation has highlighted the absence of genes encoding the typical UPEC virulence factors, but the retention or accumulation of factors proposed to facilitate general adaptability, colonisation of the GI tract, and the probiotic effects of EcN [28, 29]. These include a range of surface associated structures that are likely to provide the primary interface between host and microbe in the GI tract, such as flagella, fimbriae, a special truncated lipopolysaccharide (LPS) variant, and a K5 type polysaccharide capsule [6, 29–31]. In particular, structures such as flagellin, peptidoglycan and LPS, are recognised by immune regulating Toll-like receptors (TLRS) expressed by IECs, which have been established as key routes of host-microbe communication in the gut, with TLR signalling integral to epithelial homoeostasis and defence [32–34]. Signaling by several TLRs is known to be modulated either directly or indirectly by EcN derived ligands [6, 17–20, 30, 35], which include surface associated structures absent in most or all other probiotic organisms. The K5 capsule produced by EcN in particular is notable in this context, and although not a ligand for known TLRs, the EcN capsule has been implicated in the interaction of this organism with IECs, and impact on chemokine expression and TLR signalling [18,19]. Nevertheless, as with other probiotics, the detailed mechanisms underlying the clinical effectiveness of EcN remain poorly understood overall, with a greater comprehension required to fully realise the potential of this important probiotic species. Here we describe the application of random transposon mutagenesis to identify genes and surface structures involved in the interaction of EcN with human intestinal epithelial cells, and provide new insight into the mechanisms through which EcN interacts with epithelial cells. Results Isolation and genetic characterisation of EcN mutants with disruptions in genes related to cell surface structures Because cell surface structures are a primary point of contact between EcN and IECs, and processes such as biofilm formation and attachment to abiotic surfaces also depends on many of the same structures, we reasoned that selection of mutants with alterations in biofilm formation would enrich for those defective in cell surface associated features also likely to be involved in EcN-IEC interaction. Therefore, we initially subjected a total of 4,116 EcN mini-Tn5 mutants to a preliminary high throughput screen for alterations in biofilm formation (both enhancements and reductions), in order to enrich for mutants attenuated in cell surface features. In this precursor biofilm screen 21 mutants were found to be significantly different in their ability to form biofilms as compared to the EcN wild-type (EcN WT), but unaltered in general growth rate. The majority of these (n = 15) exhibited a biofilm formation enhanced (BFE) phenotype, whereas six exhibited biofilm formation deficient (BFD) phenotype as compared to the WT (Table 1). Identities of genes disrupted in these mutants indicated that the majority were associated with synthesis of cell surface structures, or aspects of cell envelope biogenesis, previously linked to host-IEC interaction or intestinal colonisation (Table 1; [18, 35, 37–40]). A subset of 6 mutants disrupted in genes predicted to encode for cell surface structures, and encompassing both BFD and BFE phenotypes, were subsequently selected for further characterisation of their interaction with cultured IECs. Fig 1. Adherence of EcN mini-Tn5 mutants to Caco-2 cells. A subset of mutants recovered from biofilm screens with disruptions in genes predicted to be involved in generation of surface tstructures, were assessed for their ability to attach to Caco-2 cells in in vitro co-culture models. Caco-2 cell monolayers (~80% confluence) were exposed to bacterial suspensions from mid-log-phase cultures at an MOI of 1:1 for 4 h at 37°C, 5% CO2. Genes disrupted in mutants tested are noted in parentheses and details can be found in Table 1. Data are expressed as the mean of three replicates, and error bars show SE of the mean. Significant differences between attachment of EcN WT and mutants is indicated by ** (P ≤ or **** (P were confirmed biofilm altered mutants and defined as biofilm enhanced (BFE) or biofilm deficient (BFD) mutants. Mutants biofilm formation index was calculated as the percentage of CV (OD595) measured in the EcN WT. Genetic characterisation of biofilm-altered mutants Genes disrupted in mutants of interest were identified using a “cloning free” arbitrary PCR-based approach to amplify DNA segments flanking the transposon insertion, as described by Manoil [55] using primers listed in S2 Table. The resulting amplicons were sequenced by GATC Biotech Ltd. (London, UK) using transposon end primer pLR27Primer 3. The putative function of disrupted genes was assigned by mapping sequence data flanking the mini-Tn5 insert site to the E. coli Nissle Draft genomes sequence [28], and the previously published genomic islands [29]. Sequence reads from mutants were trimmed to remove the 5’ low quality regions (typically ~30–50 nt), and the immediate ~40 nt flanking sections correlated with the EcN genome. Where EcN genome annotations did not provide any clear indication of putative function wider searches of the nr dataset using BlastX and/or the conserved domain database were employed. Construction of kfiB and kfiC deletion mutants Deletion mutants EcNΔkfiB and EcNΔkfiC were constructed by homologous recombination using the Xer-ciseTM chromosomal modification system (Cobra Biologics, Keele, UK) according to manufacturer’s instructions and protocols described by Bloor and Cranenburgh [56]. The system comprises plasmids pTOPO-DifCAT and pLGBE, for construction of target gene specific integration cassette and provision of the Red λ recombination functions, respectively. Briefly, kfiB or kfiC integration cassettes consisting of the difE. coli-cat-difE. coli region from pTOPO-DifCAT plasmid flanked by 50 nt regions homologous to the 3’ and 5' ends of the target gene, were generated by PCR using 70-nt primers, or (listed in S2 Table). EcN WT was first transformed with the Tc-selectable plasmid pLGBE and transformants EcN-pLGBE were used to generate electrocompetent cells, which were subsequently transformed with the PCR product of the difE. coli-cat-difE. coli integration cassette constructs. Integrants were selected on LB agar supplemented with 20 μg ml–1 Chloramphenicol. Loss of pLGBE and generation of chloramphenicol-sensitive clones, indicating resolution of difE. coli-cat-difE. coli marker genes by native recombinases and generation of markerless deletion mutants (mutants EcNΔkfiB and EcNΔkfiC) was achieved by sub-culturing the integrants in LB broth in the absence of antibiotics. Loss of pLGBE was verified by plasmid extraction, and by PCR for marker cassettes kfiB or kfiC specific primers EcNkfiB _F/R or EcNkfiC _F/R, respectively, and confirmed by PCR. Examination of polar effects in EcNΔkfiB and EcNΔkfiC mutants The effect of gene deletion or disruptions in kfiB and kfiC mutants, on the expression of downstream genes (polar effects) was assessed using RT-PCR. Total RNA was extracted from mid-log-phase bacterial cells using the RNeasy Protect Cell Mini Kit (Qiagen) according to manufacturer’s instructions, and treated using the Ambion TURBO DNA-free system (Ambion-Life technologies, Paisley, UK) to remove any potential DNA contamination. The treated RNA was used to generate cDNA using the One Step RT-PCR kit (Qiagen) according to the manufacturer’s instructions, utilising 15 ng RNA per reaction as template. Resulting cDNA was used as template in standard PCRs for detection of gene transcripts with specific primers detailed in S2 Table. Confirmation of K5 capsule absence in EcNΔkfiB and EcNΔkfiC mutants The K5 capsule-specific bacteriophage (ΦK5) [57] was used in this study to determine if the K5 capsule was expressed by EcN WT and deletion mutants. The bacteriophage was diluted and maintained in phage dilution buffer (PDB) (100 mM NaCl, 8 mM MgSO4, gelatine, 50 mM Tris pH Cultures of mutants EcNΔkfiB and EcNΔkfiC, controls EcN WT and MG1655 were grown in LB with shaking at 37°C to an OD600 of then pelleted by centrifugation (10,000 × g for 10 min) and resuspended in ice-cold 10 mM MgSO4. Aliquots of cell suspension (100 μl) were mixed with 100 μl of the appropriate bacteriophage dilution (ranging from 101 to 109 PFU ml–1 from stock suspension of × 109 PFU ml–1) in sterile mL Eppendorf tube then incubated at RT for 30 min, statically. The phage-bacteria mixture was added to a volume of 3 ml of soft agar (1% NaCl, yeast extract, 1% tryptone, agar) held at 42°C in 15 ml sterile glass tube, and the content of the tubes were mixed gently by swirling. The inoculated soft agar was poured on top of LB agar and incubated for 16 h at 37°C to allow formation of plaques. Intestinal epithelial cell culture and co-culture conditions Caco-2 cells (passage 51–79) were grown at 37°C with 5% CO2 in Dulbecco's modified Eagle's medium (DMEM, g glucose l–1) supplemented with 10% fetal bovine serum and 1× non-essential amino acids (PAA Laboratories, Somerset, UK). Cells were seeded into 6-well or 96-well plates, grown up to ~ 60–80% confluence, and used in co-culture experiments with bacteria. Mid-log-phase bacteria (OD600 of were washed with PBS and suspended in DMEM to the required final count, corresponding to the appropriate multiplicity of infection (MOI) and added to Caco-2 monolayers before plates were incubated at 37°C and 5% CO2. Bacterial adherence to Caco-2 cells Adherence was calculated according to the strategy employed by Hafez et al. [18]. Mid-log phase bacteria cultures were suspended in DMEM then added to monolayers of Caco-2 grown in 6-well plates (80% confluence) at an MOI of 1:1 and incubated at 37°C and 5% CO2 for 4 h. The monolayers were washed 3 times with PBS to remove non-adherent cells then treated with lysis solution, 1% wt / vol saponin (Sigma Aldrich) in trypsin-EDTA (PAA Laboratories, Somerset, UK) for 10 min to allow permeabilisation of Caco-2 cells and recovery of total cell-associated bacteria. Cells were mixed gently by pipetting, serially diluted in sterile PBS, plated onto LB agar, and incubated at 37°C overnight. The obtained viable count represented the total number of cell associated bacteria (adherent and internalised). Internalised bacteria were calculated using the same protocol but Caco-2 cells were treated with gentamicin for 2h (200 μg ml-1) to kill external bacteria prior to lysis and enumeration. The number of adherent bacteria was taken as the difference between total cell associated bacteria and internalised bacteria. The effect of EcN mutants on induction of apoptosis in Caco-2 cells The effect of EcN mutants on induction of apoptosis Caco-2 cells was assessed by measuring the activity of caspase 3/7 using the Caspase-Glo 3/7 kit (Promega, Southampton, UK), according to manufacturer’s instructions. Cells were seeded in 96-well plates with 5,000 cells/well and cultured to achieve ~ 60% confluence then treated with bacteria or bacterial supernatants in co-culture. Media was replaced with serum-free DMEM for 12 h prior to the treatment. Bacterial suspensions were prepared in serum-free DMEM from mid-log-phase cultures then added to Caco-2 cells at an MOI of 10:1 (bacteria:Caco-2) in a final volume of 100 μl/ well. The plates were incubated for 2 h at 37°C and 5% CO2 then media was replaced with fresh serum-free DMEM supplemented with gentamicin at 200 μg ml–1 to stop bacterial growth, and plates were incubated for another 10 h. Bacterial supernatants were obtained from cells grown in 5 mL serum-free DMEM at 37°C overnight, with shaking, and recovered by centrifugation (1,500 × g for 10 min), pH adjusted to and filter-sterilised ( The supernatants were diluted in fresh serum-free DMEM at a ratio of 1:1, and used in place of cell suspensions as described above. Caspase 3/7 activity was measured as relative light units (RLUs) using a Synergy Multi-Mode Plate Reader (BioTek, Potton, UK) operated with BioTek software. Analysis of cytotoxicity The effect of EcN strains on induction of cytotoxicity in Caco-2 cells was assessed by measuring the amount of lactate dehydrogenase (LDH) released into the co-culture media, using the CytoTox 96 Non-Radioactive Cytotoxicity Assay kit (Promega). Caco-2 cells were treated with bacteria and controls as described for the analysis of apoptosis (above) and both assays were performed in parallel. After treatment of Caco-2 cells, supernatants were collected from plate wells using a multichannel pipette then transferred to fresh 96-well at 50 μl/well. The supernatant was diluted further in serum-free culture media then mixed with the CytoTox 96 substrate at a ration of 1:1. Plates were incubated in the dark at room temperature for 30 min and absorbance at 490 nm (OD490) was recorded. The percentage of cytotoxicity was calculated as LDH released in treated cells (OD490)/maximum LDH release (OD490) × 100. Maximum release was determined as the amount released by total lysis of untreated Caco-2 cells with the CytoTox 96 lysis Solution (10X). Analysis of cellular and nuclear morphology Membrane integrity and nuclear morphology of Caco-2 cells were analysed by fluorescent phalloidin (F-actin) and Dapi (DNA) stainings. Cells were grown on sterile glass cover slips in 6-well plates then treated with EcN strains and controls (MG1655 and mM camptothecin; Sigma) as described above (analysis of apoptosis). After the treatments, the cells on coverslips were washed with PBS then fixed with 4% formaldehyde (Sigma) in PBS for 20 min at RT. The fixed cells were washed three times with PBS and permeabilised with Triton X-100 (Sigma) in PBS for 5 min at RT. The cells were washed three times with PBS, 5 min per wash with gentle rocking, then treated with a μg ml–1 solution of fluorescein isothiocyanate-phalloidin (Sigma- Aldrich) in PBS for 1 h at RT in the dark. The cells were washed twice with PBS and were mounted with the Fluoroshield DAPI medium (Sigma) and examined under a Leica TCS SP5 Confocal Laser Scanning microscope (Leica Microsystems, Wetzlar, Germany). Analysis of COX-2 expression The expression of COX-2 protein in Caco-2 co-cultures was analysed by western blotting using standard methods. Briefly, Caco-2 cells were seeded in 6 wells plates, and at ~ 60% confluence, were treated with EcN K5 mutants and controls as described above (analysis of apoptosis). Lipopolysaccharide (LPS, final concentration, 5 μg ml–1) from Salmonella enterica (Sigma, UK) and human tumour necrosis factor alpha (TNF-α, 10 ng ml–1) (Sigma, UK) were used as pro-inflammatory stimulator positive controls. Treated Caco-2 cell monolayers were washed 3 times with PBS, trypsinised then resuspended in 100 μl of hypotonic buffer (10 mM HEPES, 10 mM KCl, mM EDTA, mM EGTA, 1 mM DTT in SDW, pH containing Sigma protease inhibitor cocktail (1:20), for 15 min at 4°C. Cells were lysed in 25 μl 10% Triton X-100 for 30 min and total protein obtained by centrifugation (10,000 g for 1 min at 4°C). Protein concentration was determined by the Bradford method (Bio-Rad) and equivalent amounts of protein lysates (10 μg) separated by electrophoresis on SDS—PAGE (10%), and then transferred onto a nitrocellulose membrane (GE Healthcare, Giles, UK). The blots were blocked at RT with 10% skimmed milk powder in TBST buffer (10 mM Tris, pH M NaCl, Tween 20), and incubated with primary antibody, anti-COX-2 rabbit polyclonal (Abcam, Cambridge, UK) 1:1,000 in TBST, overnight at 4°C. Blots were washed with TBST then incubated with anti-rabbit HRP-conjugated secondary antibody (Sigma, UK) 1:5,000 in TBST, for 1h at RT. Membranes were washed further then visualised by incubation with the ECL chemiluminescent reagent (Amersham, Little Chalfont, UK) and exposed to Kodak Image Station 440 for signal detection. Blots were then stripped and reprobed with loading control anti-GAPDH mouse monoclonal (Ambion, Cambridge, UK); anti-mouse IgG HRP-conjugated (Sigma, UK) as secondary antibody. The bands of COX-2 densitometry readings were normalized to the GAPDH control. Analysis of cell morphology and aggregation Bacteria were grown statically in 5 mL LB in 50 mL sterile polystyrene tube at 37°C for 16 h. The cultures were mix gently by swirling and 3 μL of each was directly transferred onto glass slide, allowed to rest for 1 min then covered with a cover slip and visualised using ×40 magnification phase contrast microscopy. For each culture 10 randomly selected fields of view across each slide were captured using the Olympus Cell Sense software, and subsequently reviewed. Representative images were selected and adjusted only for brightness and contrast. Statistical analysis All statistical analysis was performed using Prism For Mac OS X (Graphpad Software inc. USA; Data was analysed using either Student’s t-test, or ANOVA with the Bonferroni correction for multiple comparisons. Supporting InformationS1 Fig. Overview of K5 capsule biosynthesis in E. coli, and associated genes disrupted in this show the genetic organisation of the K5 gene cluster in E. coli Nissle 1917 based on data from Cress et al. [28]; Grozdanov et al. [29], and an overview of the current model for K5 capsule biosynthesis and assembly adapted from Griffiths et al. [36]; Whitfield [41]; Petit et al. [42]; Bliss et al. [43]; Hodson et al. [44]; Corbett and Roberts [45]; Whitfield and Roberts [46]; Rigg et al. [47]; Whitfield and Willis [58]. A) Physical map of the EcN K5 capsular polysaccharide gene cluster. Region I (kpsF,E,D,U,C,S) and Region III (kpsM,T) encode elements of synthesis and export machinery, and are conserved among E. coli strains generating Group 2 polysaccharide capsules. Region II encodes K5 specific polysaccharide synthesis machinery (kfiA,B,C,D). Genes disrupted by transposon mutagenesis (kfiB, kpsT) and/or subject to gene knockout (kfiB,C) in this study are identified. HP—denote hypothetical proteins of unknown function B) Representation of main stages and associated K5 biosynthetic machinery (stages 1–3). K5 assembly is localised to the cytoplasmic face of the inner membrane, and is underpinned by the formation of a biosynthetic complex which catalyses synthesis and export polysaccharide precursors for incorporation in the maturing capsule on the cell surface. During K5 assembly it is believed that a unified biosynthetic complex is developed which progressively catalyses main stages [1–3]. However, for clarity here we have separated each main stage of K5 synthesis and associated membrane complexes. Stage 1) Proteins encoded by kpsF,U,C,S are believed to be responsible for the initial generation of the phospatyidyl acceptor and Kdo linker (keto-3-deoxy-manno-2-octulosonic acid), upon which the polysaccharide chain is synthesised. Stage 2) Proteins encoded by kfiA-D are responsible for synthesis of the polysaccharide chain through addition of alternating units of GlcA (glucuronic acid) and GlcNAc (N-acetyl-glucosamine) from UDP-sugar precursors. Stage 3) Proteins generated by kpsD,E,M,T form an ABC transporter complex that translocates completed polysaccharide chains to the cell surface, in an energy dependant process. Acknowledgments We wish to thank Prof Jun Zhu (University of Pennsylvania, School of Medicine) and Prof Ian Roberts (University of Manchester, Faculty of Life Sciences) for gifts of pRL27::mini-Tn5 system and ΦK5 bacteriophage, respectively. 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View Article Google Scholar Maintaining remission of ulcerative colitis with the probiotic Escherichia coli Nissle 1917 is as effective as with standard mesalazine Free W Kruis1, P Frič2, J Pokrotnieks3, M Lukáš4, B Fixa5, M Kaščák6, M A Kamm7, J Weismueller8, C Beglinger9, M Stolte10, C Wolff11, J Schulze111Evangelisches Krankenhaus Kalk, University of Cologne, Germany2Ustředná vojenská nemocnice, II interní oddělení, Praha, Czech Republic3Paula Stradina Clinical University Hospital, Riga, Latvia4IV Interni Klinika, Charles University, Praha, Czech Republic52nd Department of Medicine, Charles University Prague, Medical Faculty, Hradec Kralove, Czech Republic6Interné oddelenie NsP, Trenčín, Slovak Republic7St Mark’s Hospital, London, UK8Private Practice, Koblenz, Germany9Division of Gastroenterology, University Hospital, Basel, Switzerland10Institut für Pathologie, Klinikum Bayreuth, Germany11Ardeypharm, Herdecke, GermanyCorrespondence to: Dr W Kruis Evangelisches Krankenhaus Kalk, Buchforststr 2, 51103 Cologne, Germany; Abstract Background and aim: Evidence exists for the pathogenic role of the enteric flora in inflammatory bowel disease. Probiotics contain living microorganisms which exert health effects on the host. We compared the efficacy in maintaining remission of the probiotic preparation Escherichia coli Nissle 1917 and established therapy with mesalazine in patients with ulcerative colitis. Patients and methods: In total, 327 patients were recruited and assigned to a double blind, double dummy trial to receive either the probiotic drug 200 mg once daily (n = 162) or mesalazine 500 mg three times daily (n = 165). The study lasted for 12 months and patients were assessed by clinical and endoscopic activity indices (Rachmilewitz) as well as by histology. The primary aim of the study was to confirm equivalent efficacy of the two drugs in the prevention of relapses. Results: The per protocol analysis revealed relapses in 40/110 ( patients in the E coli Nissle 1917 group and 38/112 ( in the mesalazine group (significant equivalence p = Subgroup analyses showed no differences between the treatment groups in terms of duration and localisation of disease or pretrial treatment. Safety profile and tolerability were very good for both groups and were not different. Conclusions: The probiotic drug E coli Nissle 1917 shows efficacy and safety in maintaining remission equivalent to the gold standard mesalazine in patients with ulcerative colitis. The effectiveness of probiotic treatment further underlines the pathogenetic significance of the enteric flora. UC, ulcerative colitisIBD, inflammatory bowel diseaseEcN, Escherichia coli Nissle 1917GCP, good clinical practiceCAI, clinical activity indexEI, endoscopic indexITT, intention to treat populationPP, per protocol population5-ASA, 5-aminosalicylic acidulcerative colitismaintenance therapyprobioticsEscherichia coli Nissle Statistics from Request Permissions If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways. UC, ulcerative colitisIBD, inflammatory bowel diseaseEcN, Escherichia coli Nissle 1917GCP, good clinical practiceCAI, clinical activity indexEI, endoscopic indexITT, intention to treat populationPP, per protocol population5-ASA, 5-aminosalicylic acidulcerative colitismaintenance therapyprobioticsEscherichia coli Nissle Ulcerative colitis (UC) is a chronic relapsing disease. The aims of treatment are induction of remission and prevention of relapses. Guidelines1,2 recommend aminosalicylates for maintenance treatment. Aminosalicylates exert various effects on leukotrienes, cytokines, and oxygen Their mode of action in UC remains unclear. It is suggested that the sum of their anti-inflammatory activities constitutes their therapeutic principle. Thus maintenance treatment with aminosalicylates is only effective when inflammation starts, but not in the non-inflamed gut. Growing evidence exists for a role of the intestinal microflora in the pathogenesis of inflammatory bowel disease (IBD). Findings from genetically engineered animal models as well as clinical observations have elucidated the importance of commensal Antibacterial treatment showed some beneficial effects7,8 but the use of antibiotics is limited. Therefore, treatment with probiotics has been proposed. Probiotics are viable non-pathogenic microorganisms that confer health benefits to the host by improving the microbial balance of the indigenous Apart from anecdotal experience, two controlled studies with the probiotic bacterial strain Escherichia coli Nissle 1917 (EcN) in UC already These trials showed no difference between the relapse preventing effects of EcN and standard mesalazine. However, some criticism was raised as to the validity of these The present study was undertaken to confirm that the relapse preventing effects of probiotic therapy with EcN and standard mesalazine are equivalent. MATERIALS AND METHODS The study was conducted according to the Helsinki Declaration (revised version of Hong Kong) and adhered to good clinical practice (GCP) guidelines. The study was approved by the Ethikkommission der Ärztekammer Nordrhein, Germany, as well as by the local ethics committees of the participating centres. All patients received material in their own language and gave written informed consent. Patients were included in the study if aged 18–70 years and diagnosed with UC in remission (clinical activity index (CAI) ⩽4, endoscopic index (EI) ⩽4, and no signs of acute inflammation on histological examination). In addition, inclusion criteria comprised at least two acute attacks of UC prior to the study and a duration of the current remission of no longer than 12 months. Exclusion criteria were: active UC; proctitis with up to 10 cm proximal spread; Crohn’s disease; infectious colitis; severe accompanying illnesses or major colonic surgery; use of antibiotics, sulphonamides, steroids, or other therapies for UC at entry into the trial; administration of EcN within the previous six months before trial entry; as well as known intolerance to salicylates. Study medication The investigational drug was a bacterial preparation for oral use containing non-pathogenic Escherichia coli of strain Nissle 1917 (serotype O6:K5:H1). Capsules were enteric coated to protect the microorganisms from gastric juice and contained viable bacteria (Mutaflor 100 mg; Ardeypharm GmbH, Herdecke, Germany). The control preparation was mesalazine, consisting of eudragit L coated 5-aminosalicylic acid (Salofalk500 mg; Dr Falk Pharma GmbH, Freiburg, Germany). The test group received one capsule of Mutaflor 100 mg once daily and one tablet of placebo three times daily from day 1 to day 4, and two capsules of Mutaflor 100 mg once daily and one tablet of placebo three times daily from day 5 to the end of the study. The control group received one capsule of placebo once daily and one tablet of Salofalk 500 mg three times daily from day 1 to day 4, and two capsules of placebo once daily and one tablet of Salofalk 500 mg three times daily from day 5 to the end of the study. No concomitant medication for UC was allowed throughout the study. Study design This was a randomised, double blind, double dummy trial comparing the relapse preventing effects and safety of a bacterial preparation containing viable EcN and mesalazine for 12 months in patients with UC in remission. The study was conducted in 60 hospitals and private settings in 10 European countries (see list of participating investigators in the appendix). Randomisation was carried out in a double blind manner in blocks of four patients using 1:1 allocation to the two treatment groups. Only complete blocks of random numbers were used for each centre. If patients were eligible for study entry, they were assigned to random numbers ( = patient numbers) in ascending order within each centre according to the chronological order of their randomisation and were given the corresponding study medication. Evaluation Clinic visits were required at the start and end of the study as well as after 1, 2, 3, 6, and 9 months of treatment. The primary objective of the study was to compare the number of patients experiencing a relapse of UC during the 12 month observation period between the two treatment groups. Patients were classified as suffering a relapse when all three of the following criteria were met: CAI >6 or an increase in CAI of at least 3 points with CAI = 4 being exceeded at the same time; EI >4; and histological signs of acute inflammation. CAI was defined according to At trial entry and at the end of the study, patients underwent colonoscopy where biopsies were taken. Endoscopic activity was assessed using a four point index14: granularity, vascular pattern, vulnerability of mucosa, and mucosal damage. All biopsies were examined by a single pathologist using a four point Secondary efficacy variables were the physician’s and patient’s assessment of general well being and calculation of a quality of life Additionally, time to relapse, CAI, EI, and histological findings were documented. Laboratory assessments, including erythrocyte sedimentation rate, C reactive protein, orosomucoids, blood counts, liver enzymes, creatinine, serum iron, and serum albumin were performed at trial entry and at the end of the study. Incidence and severity of adverse events were reported according to GCP for clinical trials of medication in the European Community (91/507/EWG, CPMP/ICH/135/95). Tolerance of the study medication was assessed on a four point scale (very good, good, fair, poor), and patient compliance was ascertained by pill counting. Statistical analysis The aim of the study was to statistically confirm one sided equivalent efficacy of EcN and mesalazine in preventing relapses of UC. Relapse rates were compared using the one sided test of Farrington and Manning17: this tests the null hypothesis that the difference between treatment groups is greater than or equal to the upper equivalence margin Δ of 20% versus the alternative that the true difference is less than 20% (α = upper confidence limit 95%). Assuming a 12 month relapse rate of 30% under mesalazine treatment and 35% under EcN treatment, to reach a statistical power of 80% at least n = 127 patients were required in each treatment group according to the sample size term for comparative binomial trials with the null hypothesis of non-zero risk Two sets of patients were analysed: an intention to treat population (ITT), including all patients who took at least one dose of the study medication, and a per protocol population (PP). According to generally accepted standards for equivalence and non-inferiority trials,18 primary analysis of the main objective (difference in relapse rates) was based on the PP population. Assuming 25% protocol violators, a total number of 160 patients in each treatment group was therefore planned. Baseline comparability and statistical analysis of secondary objectives was assessed using Fisher’s exact test (two sided; α = In addition, Kaplan-Meier curves were plotted. If no CAI or other parameter was documented at the individual study end, the “last observation carried forward” method was applied. Results are given as mean (SD). Statistical tests were executed using SPSS software package version under the Microsoft Windows NT operating system. For exploratory comparisons (tables 2, 3), the Student’s t test was used. RESULTS Patient characteristics In total, 327 patients were enrolled and randomised to either the EcN preparation (n = 162) or mesalazine (n = 165). The two patient groups were matched with regard to demographic, clinical, and pretreatment characteristics (table 1). The time gap between the end of the last relapse before the study and entry into the study was not longer than four weeks in of patients receiving EcN and in receiving mesalazine, and not longer than three months in and of EcN and mesalazine patients, respectively. All 327 randomised patients received at least one dose of the study medication and thus were included in the ITT and safety analysis this table:View inline Table 1 Demographic data and prestudy clinical characteristics Before unblinding the study, a steering committee assessed protocol violations in 105/327 ( patients. Major protocol deviations comprised violation of inclusion criteria (CAI ⩽4, EI ⩽4, and no signs of acute inflammation on histological examination) (32 patients in both groups), premature discontinuation of the study without relapse (see below), and unknown or not unequivocally assessed end point (EcN 29 patients, mesalazine 24 patients). Accordingly, the PP analysis set comprised 222 patients (EcN 110, mesalazine 112). Mean duration of the study observation period was 250 (144) (median 357) days in the EcN group and 287 (125) (median 360) days in the mesalazine group. The number of patients in the study at the scheduled visits is shown in fig 1. Premature discontinuation of the study for reasons other than relapse of disease occurred in 39/327 ( patients (in 19/162 ( patients in the EcN group and in 20/165 ( patients in the mesalazine group) (table 2). Newly emerged exclusion criteria during the study were start of concomitant medication in four patients on EcN. One patient on mesalazine became afraid of 5-aminosalicylic acid (5-ASA) and another patient underwent cardiac this table:View inline Table 2 Reasons for premature discontinuation of the study Relapse (primary objective) PP analysis revealed relapse in 40/110 ( patients in the EcN group and in 38/112 ( patients in the mesalazine group (fig 2), resulting in significant equivalence between the two groups (p = The corresponding one sided upper 95% confidence limit for the difference in treatment was (that is, within the equivalence range of 20%). Figure 3 depicts the probability of remaining in remission by Kaplan-Meier curves. Median time to relapse in the EcN group could not be calculated due to the large number of late censorings. In the mesalazine group it was 386 days. ITT analysis confirmed these results, showing a relapse rate of in the EcN group and in the mesalazine group (significant equivalence p = The upper limit of the 95% confidence interval for the difference in treatment was Subgroup analyses (secondary objectives) All subgroup analyses were performed in the ITT population. CAI increased in all patients by ( points over the study period, showing a slightly larger increase in the EcN group ( ( than in the mesalazine group ( ( No differences were observed in EI or histology between the start and end of the study (fig 4). Table 3 lists relapse rates with regard to duration, localisation, and pretrial treatment. There were no significant differences between the treatment groups for any of these characteristics. Quality of life scores on admission were ( in the EcN group and ( in the mesalazine group. Respective values after 12 months were ( and ( No significant changes occurred during the 12 month observation this table:View inline Table 3 Relapse rates according to clinical characteristics (intention to treat population) Safety and tolerance As rated by the patients, overall tolerance was very good or good in the EcN group in and in the mesalazine group in According to the physician’s assessment, the respective values were and Discontinuation of the study medication due to adverse events (relapse included) occurred in 22 ( patients (11 ( in the EcN group and 11 ( in the mesalazine group). Most frequent reasons were gastrointestinal disorders such as bloody stools, nausea, diarrhoea, mucous secretion (EcN mesalazine and abdominal pain (EcN mesalazine Generally, no unexpected drug reactions occurred during the study. No deaths but 17 serious adverse events were reported in 13/327 (4%) patients (EcN 7, mesalazine 6). Each serious adverse event occurred only once. Adverse events were reported in 68/162 ( patients treated with EcN and in 58/165 ( patients treated with mesalazine. Many adverse events reflect symptoms common for active UC such as bloody stools ( diarrhoea ( and abdominal pain ( The most frequent non-intestinal adverse events were viral infections (EcN mesalazine nausea ( and headache ( Laboratory tests showed no significant alterations. DISCUSSION Most controlled trials are designed to test differences in efficacy. In contrast, our trial was aimed at proving equivalence. Indeed, we demonstrated that the probiotic EcN provides significantly equivalent efficacy in preventing relapses of UC and is not inferior to the established gold standard mesalazine. This result was not only confirmed by statistical analysis of the PP population, which is preferred in equivalence studies,18 but also by ITT analysis. Therapeutic efficacy is usually demonstrated by superiority in a placebo controlled trial. In serious disease however when effective therapy exists that has already been tested by comparison with placebo, additional placebo controlled trials may be considered A meta-analysis19 reviewed 16 studies of maintenance therapy involving 2341 patients with UC. In four of these 16 trials, preparations containing 5-ASA were compared with placebo; in the remaining 12 studies sulphasalazine was compared. 5-ASA was observed to be significantly more effective than placebo in all dosage subgroups (<1 g/day, 1– g/day, ⩾2 g/day). A dose dependent trend was not Indeed, some studies comparing at least two doses were performed showing mainly negative or conflicting results20: Pentasa 3 g/day was not superior to g/day; balsalazide 4 g/day was better than 2 g/day; balsalazide 6 g/day was better than 3 g/day in one study but in another trial was similarly effective; and two studies with olsalazine reached different conclusions. Thus superior efficacy of doses higher than g/day has not been It can be stated that mesalazine g/day presently reflects the standard in the prevention of UC relapses and thus it qualifies as a control in an equivalence trial. Previous studies on EcN were criticised12,13 for several reasons—for example, short observation period10 or heterogeneity of patients and outcome The present trial considered this critique and followed actual standards. The observation period was 12 months, only patients with UC in remission were included, and the clinical outcome was assessed by well established endoscopic and histological activity indices resulting in a low relapse rate for the mesalazine group comparable with previous A total of 327 patients were included to achieve a statistical power sufficient to test for equivalence in a one sided set. Most likely, IBD is caused by an unrestrained inflammatory response to as yet undefined agents. Although precise identification of the antigenic stimuli has not been determined, the intestinal microflora represents a likely To manipulate the resident gut bacteria therefore seems to offer a rational approach to maintaining remission in IBD. One way of doing this, which has gained credence over recent years, is by using Mechanisms which may account for probiotic activity include production of antimicrobial agents, inhibition of adhesion of pathogens, and influence on mucosal barrier It was reported that inhibition of nuclear factor κB could be mediated by probiotic The properties of EcN are well characterised25 and its genome has been extensively It carries non-pathogenic adhesion molecules. A specific lipopolysaccharide renders it immunogenic without showing any immunotoxic Immunomodulating activity was demonstrated for specific immune responses as well as for induction of non-specific natural immunity in preterm EcN develops antagonistic activity against enterobacteria such as Salmonella enteritidis, Shigella dysenteriae, Yersinia enterocolitica, and Vibrio It prevents invasion of Salmonella typhimurium into intestinal cells,31 inhibits adhesion and invasion of adherent invasive E coli,32 and reduces concentrations of mucosa associated colonic microflora constituents in EcN is safe. Molecular genetics as well as functional analyses have revealed that EcN does not produce any virulence factors or carry any genes for pathogenicity It does not bear genes for antibiotic resistance, transferable genes or plasmids, and does not take up foreign pathogenic DNA. No formation of enterotoxins, cytotoxins, or haemolysins has been observed and there is no serum Clinical studies have demonstrated a favourable safety profile for EcN compared with placebo,35,36 mesalazine,10,11 and Our study confirms this excellent safety and tolerance record. There are other controlled studies with different probiotics. Relapse prevention with Lactobacillus GG tested negatively for maintenance therapy in surgically induced remission of Crohn’s disease38 but a small study showed positive results when Saccharomyces boulardii was added to Inflammation of the ileal pouch constructed after proctocolectomy and ileoanal anastomosis in patients with UC is of particular interest because bacterial growth seems to be of pivotal pathophysiological significance. Cases successfully treated with EcN have been A formulation comprising eight different probiotic bacteria demonstrated convincing therapeutic effects in primary prevention41 and chronic In an uncontrolled study, this preparation was able to colonise the gut and maintain remission in patients with In conclusion, the use of probiotics in IBD is in accordance with its pathogenesis. They may prevent induction of inflammatory reactions. EcN shows therapeutic efficacy and safety in maintaining remission in UC. It can be considered as an alternative to mesalazine. APPENDIX The following institutions, local principal investigators, and local coordinators participated in this study: Austria: University Hospital, Graz: W Petritsch. Czech Republic: Nemocnice Milosrdnych sester sv Karla Boromejského, Prague: J Dosedel; University Hospital, Hradec Kralove: B Fixa; Central Military Hospital, Prague: P Frič; University Hospitals, Prague: M Kment, M Lukáš; University Hospital Plzen: J Koželuhová; University Hospital Brno: H Simonová; Masaryk Hospital, Ústí nad Labem: K Mareš, J Stehlík. Estonia: Central Hospital, Tallin: B Margus; University Hospital, Tartu: R Salupere. Germany: Private Practice, Essen: A Boekstegers; University Hospital, Jena: H Bosseckert; University Hospital, Regensburg: V Gross; DRK-Kliniken Westend, Berlin: R Büchsel; Charité-Campus Virchow, Berlin: A Dignass; Private Practice, Rottenburg aN: F Dreher; Private Practice, Frankenberg: R Engelhard; Private Practice, Bad Homburg: G Ermert; Private Practice, Karlsruhe: U Farack; Private Practice, Marburg: J Hein; Kreisklinik München-Pasing, München: J Heinkelein; Mittelrhein-Klinik Bad Salzig, Boppard: R Herz; Private Practice, Bautzen: I König; Ev Krankenhaus Kalk, Köln: W Kruis; Private Practice, Münster: Th Krummenerl; Private Practice, Cottbus: A Kühn; Israelitisches Krankenhaus, Hamburg: P Layer; University Hospital, Dresden: G Lobeck; Charité-Humboldt-University, Berlin: H Lochs; Private Practice, Neuenkirchen: R Moellmann; Private Practice, Cottbus: E Muehlberg; University Hospital Großhadern, München: Th Ochsenkühn; Städtisches Klinikum Friedrichstadt, Dresden: H Porst; Krankenhaus Tabea, Hamburg: A Raedler; University Hospital, Erlangen: M Raithel; Krankenhaus Nordwest, Frankfurt: W Rösch; University Hospital, Bonn: Ch Scheurlen; Private Practice, Gera: U Schindler; Private Practice, Reutlingen: W Schmeißer; Private Practice, Regensburg: E Schütz; Krankenhaus Speyerer, Heidelberg: R Singer; University Hospital Benjamin Franklin, Berlin: R Stange; University Hospital, Frankfurt: J Stein; Klinikum der RWTH, Aachen: Th Schönfelder; University Hospital, Mainz: R Wanitschke; Private Practice, Koblenz: A Lütke, J Weismüller; St Michael Krankenhaus, Völklingen: D Woerdehoff; Private Practice, Erlangen: J Zeus. Latvia: Paula Stradina Clinical University Hospital, Riga: J Pokrotnieks. Lithuania: University Hospital, Vilnius: A Irnius; Kauno Medicinos Akademija, Kaunas: L Kupcinskas. Slovak Republic: Comenius University Hospital, Bratislava: M Huorka; City Hospital, Trencíne: M Kaščák; University Hospital, Košice: T Hildebrand. Sweden: Sabbatsberg Naersjukhuset, Stockholm: P Benno; Karolinska Institutet: A Uribe. Switzerland: Kantonsspital-University, Basel: Ch Beglinger. UK: Leeds General Infirmary, Leeds: ATR Axon; St Mark’s Hospital, London: MA Kamm. REFERENCES↵ ↵ Stange EF, Riemann J, von Herbay A, et al. Diagnosis and therapy of ulcerative colitis—results of an evidence-based consensus conference of the German Society of Digestive and Metabolic Diseases. Z Gastroenterol2001;39:19–20. ↵ Travis SP, Jewell DP. Salicylates for ulcerative colitis—their mode of action. Pharmacol Ther1994;63:135–61. ↵ Shanahan F . Probiotics and inflammatory bowel disease: is there a scientific rationale? 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Read the full text or download the PDF: Log in using your username and password AbstractAllergic asthma is characterized by a strong Th2 and Th17 response with inflammatory cell recruitment, airways hyperreactivity and structural changes in the lung. The protease allergen papain disrupts the airway epithelium triggering a rapid eosinophilic inflammation by innate lymphoid cell type 2 (ILC2) activation, leading to a Th2 immune response. Here we asked whether the daily oral administrations of the probiotic Escherichia coli strain Nissle 1917 (ECN) might affect the outcome of the papain protease induced allergic lung inflammation in BL6 mice. We find that ECN gavage significantly prevented the severe allergic response induced by repeated papain challenges and reduced lung inflammatory cell recruitment, Th2 and Th17 response and respiratory epithelial barrier disruption with emphysema and airway hyperreactivity. In conclusion, ECN administration attenuated severe protease induced allergic inflammation, which may be beneficial to prevent allergic asthma. IntroductionAllergic asthma is one of the most common chronic respiratory diseases with a significant impact on public health1,2. In recent years, the incidence of allergic asthma in developed countries has dramatically increased and it is predicted that the number of affected people worldwide will increase by 100 million by 20253. Risk alleles have been identified for the development of asthma4 but the rapidity of its increased incidence does not support solely a genetic basis and suggest the involvement of environmental factors. Long-term observations support the notion that urban life is associated with increased prevalence of chronic immunological disorders including asthma incidence as compared to children living in farms5. Early in life microbial exposure might modulate allergic disorders6. In addition, such favorable socioeconomic factors, like enriched dietary habits or increased level of hygiene are presumably important factors for a considerable shift in the gut microbiota and increased asthma susceptibility. Epidemiological and clinical studies indicate an association between alteration of intestinal microbial communities and increased incidence of allergic asthma7. Several studies revealed changes in gut microbiota composition in adults suffering from allergic diseases at distant body sites (eczema, rhinitis, asthma)8,9, which precede the development of allergic diseases10,11. Gut bacteria outnumber the human body cells and the microbiome encode approximately 100 times more genes than the human genome12. This impressive genetic capacity contribute to essential functions for the host including nutrients supply like short-chain fatty acids (SCFAs)13,14, vitamins and hormones15, energy balance16,17,18, metabolic signaling19, resistance to pathogens colonization20,21,22 and has a key role in promoting the postnatal maturation of the intestinal mucosal barrier23,24, etiology is complex, but exposure to allergens or air pollution, are clearly important factors for the pathogenesis5. Sensitization to allergen is one of the first steps involved in asthma. Various allergens, including house dust mite (HDM), fungi, cockroach and pollen have proteolytic activities26. Protease properties of allergens cause injury of the airway epithelium with increased permeability, airway remodeling, type 2 cytokine and chemokine production and cell recruitment27. Papain, a cysteine protease, induces a type 2 response characterized by interleukin (IL)-5 and IL-13 production, mediated by an IL-2-dependent IL-9 production28 and specific IgE production29,30. There is evidence that the commensal microflora is critical in the maintenance of systemic immune tolerance, which is instrumental in protecting against allergic asthma. Escherichia coli strain Nissle 1917 (Mutaflor®, ECN) is successfully used for the treatment of intestinal inflammation, especially in patients suffering from ulcerative colitis31. In the present study, we investigated the impact of the colonization by ECN on the allergic lung inflammatory response induced by single or repeated challenges to the protease allergen papain. We show here that chronic ECN administration reduces severe allergic lung inflammation, improves the respiratory epithelial barrier function and modulates emphysema in response to repeated papain colonization has a dual effect in acute papain-induced lung inflammationTo study the impact of the administration of the ECN strain on the development of allergic inflammation, we compared the susceptibility ECN treated mice to acute papain-induced lung inflammation in comparison to non-treated controls according to the protocol shown in Fig. 1a. ECN was administered by gavage over 6 days (108 cfu of live ECN/day) then the mice were challenged twice by intranasal instillation ( of the protease allergen papain (25 µg on day 7 and 8 and the inflammatory response was analyzed 24 h later as described before32. Microscopic examinations of the lungs revealed focal inflammatory cell infiltration around bronchi, capillaries and in alveoli, as well as mucus hypersecretion (Fig. 1b). The lung inflammation as assessed by a semi-quantitative score of microscopic lesions was not reduced in ECN fed mice (Fig. 1b,c), except for the production of mucus (Fig. 1d).Figure 1ECN colonization as a dual effect in acute papain-induced lung inflammation. (a) Experimental settings of acute papaïn-induced lung inflammation and ECN treatment. (b) Lung tissues were histologically examined 24 h after the last papaïn challenge. Lung sections stained with HE from controls (NaCl/NaCl), papaïn (NaCl/Papaïn) and ECN (ECN/Papaïn)-treated mice are represented. (c) Histological score of lung inflammation infiltration was performed on paraffin embedded section after HE staining. (d) Histological score of lung mucus production was performed on paraffin embedded section after PAS staining. (e) Total cells and differential cell count of eosinophils, neutrophils, lymphocytes and macrophages were determined in BALF by numeration of MGG stained cytospin. Lung homogenate level of (F) CCL11, (g) CCL17 and (h) CXCL1 were measured by ELISA. Data are expressed as mean + SEM from a single experiment representative of 2 experiments with n = 5 mice per group. The parametric one-way or two-way ANOVA test with multiple Bonferroni’s comparison test was used. *, ** and *** refer to P < P < and P < size imagePapain-induced lung inflammation is associated with enhanced cell recruitment in the lung, involving especially eosinophils32. Cell recruitment into the broncho-alveolar lavage fluid (BALF) was modulated with increased total cells, especially neutrophils upon ECN treatment as compared to control mice (Fig. 1e) with increased myeloperoxidase (MPO) (Supplementary Figure 1) and neutrophil chemoattractant CXCL1 levels (Fig. 1h). By contrast, the recruitment of eosinophils in the BALF was significantly decreased in ECN-treated animals as compared to papain controls (Fig. 1e). This was correlated with a lowered production of CCL17 (Fig. 1g) while CCL11 levels was not modified (Fig. 1f).Interestingly, mice treated with a non-probiotic K12 E. coli strain MG1655 and tested in the acute papain model (Supplementary Figure 2A) develop a similar lung neutrophilia as compared to ECN-treated animals (Supplementary Figure 2B–D), suggesting that this effect is probably mediated an E. coli genus dependent molecular determinant. On the contrary, MG1655 treatment has no protective effect on eosinophilia as observed with cell count and chemokine production (Supplementary Figure 2B,E,F). Taken together, these results suggest that gut colonization by ECN may modulate lung inflammation by enhancing neutrophil, but importantly reducing eosinophil cell recruitment in BALF and tissue. This data motivated studies in a chronic model of lung allergic lung inflammation induced by repeated papain challenges is attenuated by ECN administrationTo determine whether ECN modulates chronic airway inflammation induced by a protease allergen papain, BL6 mice were immunized with papain (25 µg on days 6, 7 by intranasal route), followed by two intranasal challenges at day 20 and 25 (25 µg). Control mice received vehicle (NaCl). In addition, mice were orally administered with 108 cfu of live ECN (Fig. 2a). 24 h after the last papain challenge, the mice were sacrificed and the extent of the lung inflammation was assessed. Histological analysis revealed a prominent lung inflammation characterized by perivascular, peribronchial and alveolar infiltration of eosinophils, neutrophils and air space enlargement with epithelial damage and disruption of alveolar septa, a hallmark of emphysema upon papain challenge (Fig. 2b,c). ECN-treated mice largely prevented lung inflammation, epithelial injury and emphysema (Fig. 2b–d). Finally, the extensive goblet cell hyperplasia and mucus production observed in primed/challenged mice was lowered in ECN probiotic treated mice (Fig. 2b,e). Diminished mucus expression was confirmed at the mRNA level for Muc5ac in lung (Fig. 2f). Interestingly, mice treated with E. coli strain MG1655 and tested in the chronic papain model develop a similar lung inflammation as compared to untreated animals, as revealed by the histological analysis (Supplementary Figure 3A–E), suggesting that the protective effect observed with ECN is due to intrinsic probiotic properties rather than a non-specific effect due to daily gavage E. coli species on the gut microbiota. The absence of protection with MG1655 is unlikely related to the lack of gut colonization, as we quantified equivalent Enterobacteria and E. coli colony counts in both ECN- and MG1655-treated animals along the treatment (Supplementary Figure 4).Figure 2Repeated papain challenges causing severe lung inflammation is attenuated by ECN administration. (a) Experimental settings of chronic papaïn-induced lung inflammation and ECN treatment. (b) Lung tissues were histologically examined 24 h after the last papaïn challenge. Lung sections stained with HE from controls (NaCl/NaCl), papaïn (NaCl/Papaïn) and ECN (ECN/Papaïn)-treated mice are represented. (c) Histological score of lung inflammation infiltration was performed on paraffin embedded section after HE staining. (d) Histological score of airway remodeling was performed on paraffin embedded section after HE staining. (e) Histological score of lung mucus production was performed on paraffin embedded section after PAS staining. (f) Muc5ac relative gene expression levels in lung tissues was measured by qPCR. Data are expressed as mean + SEM from a single experiment representative of 2 experiments with n = 5 mice per group. The parametric one-way or two-way ANOVA test with multiple Bonferroni’s comparison test was used. *, ** and *** refer to P < P < and P < size imageECN-treated mice develop reduced airway eosinophilia and Th2-driven airway inflammation upon papain chronic challengesPapain-induced chronic inflammation is characterized by a type 2 inflammatory response28. To determine whether ECN inhibited inflammatory cell recruitment, BALF cell counts were assessed for cell phenotyping. Saline sensitized and challenged mice present negligible leukocyte numbers in BALF, whereas papain-treated mice presented a dramatic increase of total cells, eosinophils and fewer neutrophils and macrophages (Fig. 3a). By contrast, ECN-treated mice had ~ less total BALF cell counts with a 2-fold reduction in eosinophils, neutrophils and macrophages. This was consistent with significant lower levels of eosinophils attracting chemokines CCL24 and CCL11 (Fig. 3b,d), EPO levels (Supplementary Figure 5) and neutrophils/monocytes chemoattractant CXCL1 (Fig. 3e), while CCL17 was unchanged in the lungs of ECN-treated mice as compared to controls. Moreover, Th2 cytokines such as IL-5 and to a lesser extent IL4 were significantly reduced in the lung of ECN-treated mice as compared to papain controls (Fig. 3f,g). The production of IFNγ was reduced, while IL17A level was unchanged in ECN probiotic-treated mice (Fig. 3h,i).Figure 3ECN-treated mice develop reduced airway eosinophilia and Th2-driven airway inflammation upon papaïn chronic challenges. (a) Total cells and differential cell count of eosinophils, neutrophils, lymphocytes and macrophages were determined in BALF by numeration of MGG stained cytospin. Lung homogenate level of (b) CCL24, (C) CCL17, (D) CCL11, (e) CXCL1, (f) IL-4, (g) IL-5, (h) IL-17 and (i) IFNγ were measured by ELISA. Data are expressed as mean + SEM from a single experiment representative of 2 experiments with n = 5 mice per group. The parametric one-way or two-way ANOVA test with multiple Bonferroni’s comparison test was used. *, ** and *** refer to P < P < and P < size imageTaking together, these data indicate that ECN gut colonization reduces papain induced Th2 immune airways hyperreactivity and respiratory barrier injury is attenuatedA hallmark of allergic lung inflammation is airways hyperreactivity (AHR), which is due functional changes of the respiratory barrier. AHR was assessed by invasive plethysmography in untreated and ECN-treated mice upon chronic papain exposure. Airway resistance and compliance in response to methacholine as a measure of AHR and were increased upon papain challenge. ECN administration reduced airway resistance and compliance indicating a significant amelioration of the lung function (Fig. 4a,b).Figure 4Papaïn-induced pulmonary dysfunction is attenuated by ECN. (a) Airway hyper-responsiveness to increasing doses of methacholine (Mch; 0−200 mg/ml) was measured by recording changes in lung resistance and (b) airway compliance. The pulmonary epithelial integrity was assessed by the leak of (c) Evans blue and (d) total protein in BAL. (e) Immunofluorescent staining for E-cadherin (green) on lung cryosections. (f) Quantitative evaluation of E-cadherin expression on lung sections. Data are expressed as mean + SEM from a single experiment representative of 2 experiments with n = 5 mice per group. The parametric one-way or two-way ANOVA test with multiple Bonferroni’s comparison test was used. *, ** and *** refer to P < P < and P < size imageThe protease papain induces inflammation and injury of the lung epithelium and capillaries with increased vascular permeability. The probiotic ECN has the ability to strengthen the epithelial barrier33. We used Evans Blue (EB), which binds to serum albumin, as a tracer of the capillary leak of macromolecules from the circulation into the BALF. Our data reveal that ECN treatment reduced the acute lung capillary/epithelial leak of intravenous administered EB upon papain exposure (Fig. 4c). Furthermore, total protein in BALF was also reduced (Fig. 4d). To get further insights into the role of ECN in the improvement of lung epithelial barrier function during allergic asthma, lung histological sections were analyzed for the expression of E-cadherin, a critical component of the epithelial barrier, which is crucial in the maintenance of the immunologic tolerance during airway allergic sensitization34. Immunofluorescence analysis revealed reduced E-cadherin expression concomitant with epithelial cell injury upon papain exposure, while ECN feeding attenuated the reduction of E-cadherin expression (Fig. 4e), which was confirmed by a semi-quantitative assessment of E-cadherin immunostaining (Fig. 4f).Therefore ECN colonization attenuated papain protease induced allergic lung inflammation with reduced Th2 response and airways hyperreactivity. Importantly the protease induced injury of the alveolar septae reflected by emphysema and of the respiratory barrier were significantly diminished by the probiotic strain mice has reduced Th2 lymphocytes and ILC2 activation upon papain chronic challengesTh2 lymphocytes and ILC2 accumulate in lungs after papaïn exposure and produce IL-5 and IL-1335. We determine the relative contribution of ECN on Th2 and ILC2 activation 24 h after the last allergen challenge. Lung cells were restimulated by papain and the production of cytokines was analyzed. IL-5 (Fig. 5a) and to a lesser extent IL-13 (Fig. 5b) was significantly reduced upon ECN treatment while IL-33 levels remain unchanged (Fig. 5c). Total Th2 and ILC2 producing IL-5 and IL-13 were analyzed by flow cytometry (Supplementary Figures 6 and 7). The frequency of CD3+ CD4+ IL5+ or IL13+ cells were significantly reduced in ECN-treated mice as compared to untreated controls (Fig. 5d–f). This was associated with a similar decrease of ILC2+ and ILC2+ IL13+ (Fig. 5g–i). These data indicate that ECN was able to dampen Th2 and ILC2 activation and the production of the prototypal pro-allergenic IL-5 and 5ECN-treated mice has reduced Th2 lymphocytes and ILC2 activation upon papain chronic challenges. IL-5 (a), IL-13 (b) and IL-33 (c) levels after lung mononuclear cell restimulation with papaïn for 72 h. Frequency of CD3+ CD4+ lymphocytes (d) producing IL-5 (e) or IL-13 (f) are shown. Frequency of ILC2 (g) producing IL-5 (h) or IL-13 (i) are shown. Data are expressed as mean + SEM from a single experiment with n = 5 mice per group. The parametric one-way or two-way ANOVA test with multiple Bonferroni’s comparison test was used. * and ** refer to P < and P < size imageDiscussionAllergic asthma is a major health issue with increasing incidence especially in developed countries with an epidemic feature36. Asthma etiology is complex including both genetic and environmental factors, such as exposure to allergens and/or air pollution, are important for the pathogenesis5. Data regarding the use of probiotics in the prevention of allergic diseases and asthma are conflicting37. Several different bacterial strains or combinations have been used in clinical trials to assess protective effects in the context of allergic asthma with significant reduction of both incidence and severity of allergic diseases38 which were not confirmed by others39. A meta-analysis concluded that probiotic are not efficient for the prevention of allergy40. This discrepancy may be related to the dose and duration of probiotic administration, immunomodulatory differences41 among strains, mostly Lactobacillus or Bifidobacterium probiotics42. Here we evaluated the probiotic potential of the Gram negative ECN to prevent allergic lung inflammatory allergic response induced by the protease papain. ECN drastically reduced the severity of chronic lung inflammation through the modulation of the Th2 inflammatory response, injury of the respiratory barrier and airways hyperreactivity. The beneficial effects of ECN has been demonstrated before in intestinal inflammatory disorders, especially in ulcerative colitis43. Two previous studies investigated ECN in experimental asthma. Bickert et al. using the inert protein allergen OVA observed a protection upon oral administration of ECN, but no inhibition of the Th2 immune response44. Adam et al. evaluated the prophylactic potential of ECN on recombinant house mite antigen Derp1 as mucosal antigen. ECN strongly reduced the antigen specific humoral response45. Here, using oral prophylactic administration of ECN we demonstrate for the first time a reduction of papain-induced lung inflammation and amelioration of AHR. In contrast, mice administered K12 E. coli strain MG1655 were as sensitive to lung inflammation as untreated papain challenged mice suggesting that the genetic background of the strain is of particular importance and determines its ability to act as a probiotic. Nevertheless, we observed that both E. coli strains has the ability to induce a potent lung neutrophilia. These results are in line with several papers demonstrating that ECN capsule antigen K5 was an important contributor the recruitment of neutrophil46,47. More generally, it has also been suggested that the presence of capsular antigen may induce an increased influx of pulmonary neutrophils48,49. The mechanisms by which capsular antigen modulate neutrophil response are not completely understood but may include direct effect such an upregulation of shed bacterial formylmethionyl-leucyl-phenylalanine50, a potent neutrophil chemotactic factor; or indirect by modulating the host’s generation of chemokines, including CXCL1 or IL-8 which was observed upon ECN or MG1655 of the best-characterized features contributing to the effectiveness of ECN is its ability to strengthen the epithelial barrier function51. This probiotic property of ECN has been extensively demonstrated in the context of intestinal inflammatory diseases. Asthma is often associated with mucosal barrier dysfunction52. We found that respiratory barrier dysfunction due to papain-induced inflammation and injury is alleviated by ECN with reduced protein leak and upregulation of E-cadherin. Recent studies suggests that this adhesion molecule contributes to the structural and immunological function of the airway epithelium, acting as a rheostat through the regulation of epithelial junctions and production of pro-inflammatory mediators34. Alterations of the airway epithelium enhance both allergic sensitization and airway remodeling including goblet cell hyperplasia, mucus hyperproduction and subepithelial fibrosis53 thus contributing to severe airways hyperreactivity. ECN conferred a significant reduction of inflammatory cell recruitment in BALF, lung tissue inflammation and disruption of alveolar septa with epithelial cells participate in the innate immune response of the lung and have barrier function. Barrier dysfunction favors the access of noxious or immunogenic protein or chemicals to the mucosa-associated lymphoid tissues. Thus, regulation of airway epithelial barrier function is an important checkpoint of the immune response during asthma54. In the present study, we show that ECN treatment affects a prevalent Th2 response known for papain induced lung inflammation28. We observed a significant reduction of eosinophils and eosinophil-related chemokines/cytokines associated with diminished recruitment of neutrophils and CXCL1 and IFN-γ levels. The data are consistent with previous studies showing that colonization by ECN lead to a modification of the cytokines repertoire55,56. In addition, we show for the first time that ECN treatment reduce Th2 CD4+ lymphocytes as well as ILC2 activation, resulting in decreased IL-5 and IL-13 production. The latter population is known to precede Th2 activation which is the cardinal feature of allergic asthma, culminating in airway hyperresponsiveness and Th2 cytokines and chemokines. In this setting, we investigated IL-33, which is known to be involved in ILC2 activation35 but we did not find any difference upon ECN treatment, which was also the case in another reduced allergic asthma molecular rationale behind the immunomodulatory properties of ECN has not yet been elucidated and is under investigation58. The beneficial effect of ECN could rely on the improvement of the intestinal barrier function and the resulting prevention of a continuous stimulation of the host innate immune system by the gut components. Indeed, we have recently demonstrated that ECN was able to prevent CNS inflammation through the improvement of the intestinal permeability59 showing that modulation of the gut microbiota with ECN exerts remote immunological imprinting. ECN genome encodes the production of specialized molecules that may modulate immune functions60,61,62. The intestinal mucosa represents an interface between bacterial-derived metabolites and mucosal immune processes that will influence immunological processes on the host conclusion, our findings indicate that ECN is able to prevent papain-induced lung inflammation after high dose per os administration supporting a gut-lung mucosal communication64. In addition, our results suggest that the prevention of the respiratory barrier dysfunction by probiotic treatment may be important to control allergic lung inflammation. Therefore, ECN might be considered as a valuable prophylactic or diet supplement to prevent allergic (B6) mice were bred in our specific pathogen free animal facility at TAAM-CNRS, Orleans, France (agreement D-45-234-6 delivered on March, 10 of 2014). Mice were maintained in a temperature-controlled (23 °C) facility with a strict 12 h light/dark cycle and were given free access to food and water. The experiments were performed with female mice aged 8–10 weeks using 5 mice per group, and the experiments were repeated at least twice. All animal experimental protocols were carried out in accordance with the French ethical and animal experiments regulations (see Charte Nationale, Code Rural R 214-122, 214-124 and European Union Directive 86/609/EEC) and were approved by the “Ethics Committee for Animal Experimentation of CNRS Campus Orleans” (CCO), registered (N°3) by the French National Committee of Ethical Reflexion for Animal Experimentation (CLE CCO 2013-1006).Bacterial preparation, growth conditions and administrationThe strains used in this study are the probiotic Escherichia coli Nissle 1917 (ECN) and the archetypal K12 E. coli strain MG1655. Both strains were engineered to exhibit a mutation in the rpsL gene, which is known to confer resistance to streptomycin62. Before oral administrations, ECN and MG1655 strains were grown for 6 h in LB broth supplemented with streptomycin (50 µg/mL) at 37 °C with shaking. This culture was diluted 1:100 in LB broth without antibiotics and cultured overnight at 37 °C with shaking. Bacterial pellets from this overnight culture were diluted in sterile PBS to the concentration of 109 colony forming units (cfu)/ml. Mice were treated by oral gavage with 108 cfu of ECN or MG1655 in 100 µl of PBS or 100 µl of PBS as negative lung inflammation model in miceMice were anesthetized by an iv injection of ketamine/xylazine followed by an intranasal administration of 25 µg of papain (Calbiochem, Darmstadt, Germany) in 40 µL of saline solution. Mice were euthanized by CO2 inhalation 24 h after papain administration and BALF was collected. After a hearth perfusion with ISOTON II (Acid free balanced electrolyte solution Beckman Coulter, Krefeld, Germany) lung were collected and sampled for alveolar lavage (BAL)BAL was performed by 4 lavages of lung with 500 µL of saline solution via a cannula introduced into mice trachea. BAL fluids were centrifuged at 400 g for 10 min at 4 °C, the supernatants were stored at −20 °C for ELISA analysis and pellets were recovered to prepare cytospin (Thermo scientific, Waltham, USA) glass slides followed by a Diff-Quik (Merz & Dade Dudingen, Switzerland) staining. Differential cell counts were performed with at least 400 eosinophil peroxidase (EPO) activityEPO activity was determined in order to estimate the recruitment of eosinophil counts in lung parenchyma as expressionTotal RNA was isolated from homogenized mouse lung using Tri Reagent (Sigma) and quantified by NanoDrop (Nd-1000). Reverse transcription was performed withSuperScript III Kit according to manufacturers’ instructions (Invitrogen). cDNA was subjected to quantitative PCR using primers for Muc5ac (sense 5′-CAGCCGAGAGGAGGGTTTGATCT-3′ and anti-sense 5′-AGTCTCTCTCCGCTCCTCTCA-3′; Sigma). Relative transcript expression of a gene is given as 2−ΔCt(ΔCt = Cttarget−Ctreference), and relative changes compared with control are 2−ΔΔCtvalues (ΔΔCt = ΔCttreated−ΔCtcontrol) {John, 2014 #340}.Enzyme-linked Immunosorbent assay (ELISA)Homogenized lung or cell supernatant were tested for MPO, CXCL1, CCL24, CCL11, CCL17, IL-4, IL17A and IFNγ (R&D systems Abingdon, UK), IL-13, IL-5, IL-33 (eBiosciences, San-5, Diego, USA) using commercial ELISA kits according to the manufacturer’s left lobe of lung was fixed in 4% buffered formaldehyde and paraffin embedded under standard conditions. Tissue sections (3 µm) were stained with PAS. Histological changes such as inflammation and emphysema were assessed by a semi-quantitative score from 0 to 5 for cell infiltration (with increasing severity) as described before66. The slides were examined by two blinded investigators with a Leica microscope (Leica, Germany).Determination of bronchial hyperresponsiveness (AHR)For invasive measurement of dynamic resistance, mice were anesthetized with intra-peritoneal injection of solution containing ketamine (100 mg/kg, Merial) and xylasine (10 mg/kg, Bayer), paralyzed using D-tubocuranine ( Sigma), and intubated with an 18-gauge catheter. Respiratory frequency was set at 140 breaths per min with a tidal volume of ml and a positive end-expiratory pressure of 2 ml H2O. Increasing concentrations of aerosolized methacholine ( 75 and 150 mg/ml) were administered. Resistance was recorded using an invasive plethysmograph (Buxco, London, UK). Baseline resistance was restored before administering the subsequent doses of immunofluorescence stainingLungs were fixed for 3 days in 4% PFA and submerged in 20% sucrose for 1 week. Lungs were embedded in OCT (Tissue-Teck) and 10 µM sections were prepared with cryotome (Leica). Slides were incubated 30 min in citrate buffer at 80 °C, washed in TBS-Tween and then incubated overnight with mouse-anti-mouse-E-cadherin (1 µg/ml, ab76055, Abcam). After washing with slides were treated with 0,05% pontamin sky blue (Sigma) for 15 min and then incubated with secondary AF-546 goat anti-mouse antibody (Abcam) for 30 min at room temperature. After washing, slides were incubated with DAPI (Fisher Scientific) and mounted in fluoromount® (SouthernBiotech). Lung sections were observed on a fluorescence microscope Leica (Leica, CTR6000) at x200 magnification. The slides were analyzed and semi-quantitatively scored and the MFI was epithelial barrier functionTotal protein in BAL fluid and Evans blue EB leak in BAL fluid was determined as described mononuclear cell isolation and stimulationLung mononuclear cells were isolated from mice 24 h after the last challenge as described previously67. Briefly the aorta and the inferior vena cava were sectioned and the lungs were perfused with 10 mL of saline. The lobes of the lungs were sliced into small cubes and then incubated for 45 min in 1 ml of RPMI 1640 solution and digested in 1,25 mg/ml of Liberase TL (Roche Diagnostics) and 1 mg/ml DNAse 1 (Sigma) during 1 h at 37 °C. Red blood cells were lysed with lysing buffer (BD Pharm LyseTM – BD Pharmingen). Isolated lung mononuclear single live cells were plated in round bottom 96-well plates (1 × 106/ml) and restimulated 3 h at 37 °C with PMA (50 ng/mL) and ionomicyn (750 ng/mL) in the presence of Brefeldin A (1 μl/1 × 106 cells, BD Biosciences) for intracellular flow cytometry analysis. Lung mononuclear cell (1 × 106 cells) were restimulated with 25 µg of papain in RPMI and 10% SVF at 37 °C in a 96 well plate for 3 days. Supernatants were analyzed for the presence of IL-5, IL-13 and IL-33 by ELISA (invitrogen).Flow cytometry analysis on lung mononuclear cellsLung mononuclear cells were stained with V450-conjugated anti-CD45 (clone 30F11), PerCp anti-CD3e (clone 145-2C11), FITC-conjugated anti-CD4 (clone RM4-5), PE-Cy7 -conjugated anti-ICOS (clone FITC-conjugated anti-ST2 (clone U29-93), anti B220 (clone RA3-6B2), anti FcεRI (clone MAR-1), anti CD11b (clone M1/70), anti Siglec-F (clone E50-2440) and Fixable Viability Dye eFluor™ 780 (eBioscience). After washing, cells were permeabilized for 20 min with cytofix/cytoperm kit (BD Biosciences) and stained with, eFluor 660-conjugated anti-IL13 (clone eBio13A, eBiosciences) and PE-conjugated anti-IL-5 (clone All antibodies used in this were from BD Biosciences, unless otherwise specified. Data were acquired using FACS Canto II flow cytometer and analyzed using Diva and FlowJo analysisData were analyzed using Prism version 5 (Graphpad Software, San Diego, USA). The parametric one-way ANOVA test with multiple Bonferroni’s comparison test was used. Values are expressed as mean ± SEM. Statistical significance was defined at a p-value < ReferencesAccordini, S. et al. The cost of persistent asthma in Europe: an international population-based study in adults. International archives of allergy and immunology 160, 93–101, (2013).Article PubMed Google Scholar Barnett, S. B. & Nurmagambetov, T. A. Costs of asthma in the United States: 2002–2007. 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The authors are grateful to Dieudonnée Togbé for helpful discussions and suggestions. This work was supported by ANR (ANR-GUI-AAP-06-Coliforlife), le Centre National de la Recherche Scientifique, the University of Orléans, la Région Centre (2013-00085470), European funding in Region Centre-Val de Loire (FEDER N° 2016-00110366), le Ministère de l’Education Nationale, de la Recherche et de la Technologie to RA as PhD fellowship, l’Institut National de la Santé et de la Recherche Médicale to ACM as a postdoctoral informationAuthor notesThomas SecherPresent address: INSERM, UMR 1100, Research Center for Respiratory Diseases, and University of Tours, Tours, FranceAuthors and AffiliationsIRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, FranceThomas Secher, Michèle Boury & Eric OswaldCNRS, UMR7355, Experimental and Molecular Immunology and Neurogenetics, Orleans, FranceIsabelle Maillet, Claire Mackowiak, Jessica Le Bérichel, Amandine Philippeau, Corinne Panek, Francois Erard, Marc Le Bert, Valérie Quesniaux, Aurélie Couturier-Maillard & Bernhard RyffelCHU Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse, FranceEric OswaldCentre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UPS, Inserm, CNRS, Toulouse, FranceAbdelhadi SaoudiUniversity of Orleans, Orleans, FranceValérie Quesniaux & Bernhard RyffelUniversity of Cape Town, IDM, Cape Town, Republic of South AfricaBernhard RyffelAuthorsThomas SecherYou can also search for this author in PubMed Google ScholarIsabelle MailletYou can also search for this author in PubMed Google ScholarClaire MackowiakYou can also search for this author in PubMed Google ScholarJessica Le BérichelYou can also search for this author in PubMed Google ScholarAmandine PhilippeauYou can also search for this author in PubMed Google ScholarCorinne PanekYou can also search for this author in PubMed Google ScholarMichèle BouryYou can also search for this author in PubMed Google ScholarEric OswaldYou can also search for this author in PubMed Google ScholarAbdelhadi SaoudiYou can also search for this author in PubMed Google ScholarFrancois ErardYou can also search for this author in PubMed Google ScholarMarc Le BertYou can also search for this author in PubMed Google ScholarValérie QuesniauxYou can also search for this author in PubMed Google ScholarAurélie Couturier-MaillardYou can also search for this author in PubMed Google ScholarBernhard RyffelYou can also search for this author in PubMed Google ScholarContributionsConceived and designed the experiments: and Performed the experiments: and Analyzed the data: Wrote the paper: and authorsCorrespondence to Thomas Secher or Bernhard declarations Competing Interests The authors declare no competing interests. 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To view a copy of this license, visit Reprints and PermissionsAbout this articleCite this articleSecher, T., Maillet, I., Mackowiak, C. et al. The probiotic strain Escherichia coli Nissle 1917 prevents papain-induced respiratory barrier injury and severe allergic inflammation in mice. Sci Rep 8, 11245 (2018). citationReceived: 12 September 2017Accepted: 16 July 2018Published: 26 July 2018DOI: CommentsBy submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate. Engineered Escherichia coli Nissle 1917 with urate oxidase and an oxygen-recycling system for hyperuricemia treatment Rui Zhao et al. Gut Microbes. 2022 Jan-Dec. Free PMC article Abstract Hyperuricemia is the second most prevalent metabolic disease to human health after diabetes. Only a few clinical drugs are available, and most of them have serious side effects. The human body does not have urate oxidase, and uric acid is secreted via the kidney or the intestine. Reduction through kidney secretion is often the cause of hyperuricemia. We hypothesized that the intestine secretion could be enhanced when a recombinant urate-degrading bacterium was introduced into the gut. We engineered an Escherichia coli Nissle 1917 strain with a plasmid containing a gene cassette that encoded two proteins PucL and PucM for urate metabolism from Bacillus subtilis, the urate importer YgfU and catalase KatG from E. coli, and the bacterial hemoglobin Vhb from Vitreoscilla sp. The recombinant E. coli strain effectively degraded uric acid under hypoxic conditions. A new method to induce hyperuricemia in mice was developed by intravenously injecting uric acid. The engineered Escherichia coli strain significantly lowered the serum uric acid when introduced into the gut or directly injected into the blood vessel. The results support the use of urate-degrading bacteria in the gut to treat hyperuricemia. Direct injecting bacteria into blood vessels to treat metabolic diseases is proof of concept, and it has been tried to treat solid tumors. Keywords: Escherichia coli nissle 1917; catalase; hemoglobin; hyperuricemia; urate oxidase; uric acid. Conflict of interest statement No potential conflict of interest was reported by the author(s). Figures Figure 1. The schematic diagram of an engineered EcN strain for hyperuricemia was engineered to degrade UA via the pathway in Bacillus subtilis. The ygfU gene was co-expressed to facilitate UA transport, VHb was used to improve oxygen utilization, and H2O2, a byproduct of UOX, was eliminated by KatG. The new method to induce hyperuricemia in mice was established by intravenously injecting high concentrated UA. The recombinant strain was used to treat the hyperuricemia mice by oral administration or intravenous injection. Both therapies decreased UA levels of the mice. Figure 2. The optimization of UA degradation by engineering EcN cells. (a-b). UA degradation by using crude enzymes (a) or whole cells (b) of engineered EcN expressing PucLT in different plasmids under the control of different promoters. (c) UA degradation by EcN whole cells with PucL, PucLT, and PucLM. (d) UA degradation by EcN whole cells by co-expressing ygfU. The degradation curves were determined in HEPES buffer (pH = at OD600 = for whole cells or with proteins at mg/mL for enzymatic assays. The UA degradation ability of these whole cells or crude enzyme were assayed at defined time intervals. Three parallel experiments were executed to obtain averages and calculate STDEV. The one-way ANOVA method was used to calculate the p value. The Q values were calculated to get the false discovery rate (FDR). Q ‘NS’ was marked; Q ‘ns’ was marked; Q .05, ‘ns’ was marked; p .05, ‘ns’ was marked; p < .05, ‘*’ was marked; p < .01, ‘**’ was marked; p < .001, ‘***’ was marked. Similar articles Management of hyperuricemia with rasburicase review. de Bont JM, Pieters R. de Bont JM, et al. Nucleosides Nucleotides Nucleic Acids. 2004 Oct;23(8-9):1431-40. doi: Nucleosides Nucleotides Nucleic Acids. 2004. PMID: 15571272 Review. Construction and expression of recombinant uricase‑expressing genetically engineered bacteria and its application in rat model of hyperuricemia. Cai L, Li Q, Deng Y, Liu X, Du W, Jiang X. Cai L, et al. Int J Mol Med. 2020 May;45(5):1488-1500. doi: Epub 2020 Feb 24. Int J Mol Med. 2020. PMID: 32323736 Free PMC article. Cloning and expression of a urate oxidase and creatinine hydrolase fusion gene in Escherichia coli. Cheng X, Liu F, Zhang Y, Jiang Y. Cheng X, et al. Ren Fail. 2013;35(2):275-8. doi: Epub 2013 Jan 9. Ren Fail. 2013. PMID: 23297748 Identification of a Formate-Dependent Uric Acid Degradation Pathway in Escherichia coli. Iwadate Y, Kato JI. Iwadate Y, et al. J Bacteriol. 2019 May 8;201(11):e00573-18. doi: Print 2019 Jun 1. J Bacteriol. 2019. PMID: 30885932 Free PMC article. Serum uric acid-lowering therapies: where are we heading in management of hyperuricemia and the potential role of uricase. Bomalaski JS, Clark MA. Bomalaski JS, et al. Curr Rheumatol Rep. 2004 Jun;6(3):240-7. doi: Curr Rheumatol Rep. 2004. PMID: 15134605 Review. Cited by Effect and Potential Mechanism of Lactobacillus plantarum Q7 on Hyperuricemia in vitro and in vivo. Cao J, Bu Y, Hao H, Liu Q, Wang T, Liu Y, Yi H. Cao J, et al. Front Nutr. 2022 Jul 6;9:954545. doi: eCollection 2022. Front Nutr. 2022. PMID: 35873427 Free PMC article. References Gustafsson D, Unwin R.. The pathophysiology of hyperuricaemia and its possible relationship to cardiovascular disease, morbidity and mortality. BMC Nephrol. 2013;14(1):164. doi: - DOI - PMC - PubMed Kang E, S-s H, Kim DK, K-h O, Joo KW, Kim YS, Lee H. Sex-specific relationship of serum uric acid with all-cause mortality in adults with normal kidney function: an observational study. J Rheumatol. 2017;44(3):380–19. doi: - DOI - PubMed Hafez RM, Abdel-Rahman TM, Naguib RM. Uric acid in plants and microorganisms: biological applications and genetics - A review. J Adv Res. 2017;8(5):475–486. doi: - DOI - PMC - PubMed Singh G, Lingala B, Mithal A. Gout and hyperuricaemia in the USA: prevalence and trends. Rheumatology. 2019;58(12):2177–2180. doi: - DOI - PubMed Shirasawa T, Ochiai H, Yoshimoto T, Nagahama S, Watanabe A, Yoshida R, Kokaze A. Cross-sectional study of associations between normal body weight with central obesity and hyperuricemia in Japan. BMC Endocr Disord. 2020;20(1):2. doi: - DOI - PMC - PubMed Publication types MeSH terms Substances Grant support This work was supported by the National High Technology Research and Development Program of China [2018YFA0901200]; the National Natural Science Foundation of China [31870085]; the National Natural Science Foundation of China [31961133015]; Qilu Youth Scholar Startup Funding of SDU. LinkOut - more resources Full Text Sources Europe PubMed Central PubMed Central Taylor & Francis Medical MedlinePlus Health Information Approval Year Name Type Language ESCHERICHIA COLI STRAIN NISSLE 1917 Source: Common Name English MUTAFLOR Source: Common Name English E. COLI NISSLE 1917 Source: Common Name English ESCHERICHIA COLI NISSLE 1917 Source: Common Name English DSM-6601 Source: Code English ESCHERICHIA COLI STRAIN NISSLE 1917 WHOLE Source: Common Name English Code System Code Type Description EVMPD Source: SUB76233 Created by admin on Sun Jun 27 00:47:46 UTC 2021 , Edited by admin on Sun Jun 27 00:47:46 UTC 2021 PRIMARY SUBSTANCE RECORD

escherichia coli nissle 1917