start-ver=1.4 cd-journal=joma no-vol=3 cd-vols= no-issue=2 article-no= start-page=239 end-page=246 dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=20140218 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Isolation of viable but nonculturable Vibrio cholerae O1 from environmental water samples in Kolkata, India, in a culturable state en-subtitle= kn-subtitle= en-abstract= kn-abstract= Previously, we reported that viable but nonculturable (VBNC) Vibrio cholerae was converted into a culturable state by coculture with several eukaryotic cell lines including HT-29 cells. In this study, we found that a factor converting VBNC V. cholerae into a culturable state (FCVC) existed in cell extracts of eukaryotic cells. FCVC was nondialyzable, proteinase K-sensitive, and stable to heating at <60°C for 5 min. We prepared thiosulfate citrate bile salts sucrose (TCBS) plates with FCVC (F-TCBS plates). After confirming that VBNC V. cholerae O1 and O139 formed typical yellow colonies on F-TCBS plates, we tried to isolate cholera toxin gene-positive VBNC V. cholerae from environmental water samples collected in urban slum areas of Kolkata, India and succeeded in isolating V. cholerae O1 El Tor variant strains harboring a gene for the cholera toxin. The possible importance of VBNC V. cholerae O1 as a source of cholera outbreaks is discussed. en-copyright= kn-copyright= en-aut-name=SenohMitsutoshi en-aut-sei=Senoh en-aut-mei=Mitsutoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=Ghosh-BanerjeeJayeeta en-aut-sei=Ghosh-Banerjee en-aut-mei=Jayeeta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MizunoTamaki en-aut-sei=Mizuno en-aut-mei=Tamaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=ShinodaSumio en-aut-sei=Shinoda en-aut-mei=Sumio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MiyoshiShin-ichi en-aut-sei=Miyoshi en-aut-mei=Shin-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=HamabataTakashi en-aut-sei=Hamabata en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=NairG. Balakrish en-aut-sei=Nair en-aut-mei=G. Balakrish kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=TakedaYoshifumi en-aut-sei=Takeda en-aut-mei=Yoshifumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Collaborative Research Center of Okayama University for Infectious Diseases in India, Okayama University kn-affil= affil-num=2 en-affil=National Institute of Cholera and Enteric Diseases, kn-affil= affil-num=3 en-affil=Collaborative Research Center of Okayama University for Infectious Diseases in India, Okayama University kn-affil= affil-num=4 en-affil=Collaborative Research Center of Okayama University for Infectious Diseases in India, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=Research Institute, National Center for Global Health and Medicine kn-affil= affil-num=7 en-affil=Translational Health Science and Technology Institute kn-affil= affil-num=8 en-affil=Collaborative Research Center of Okayama University for Infectious Diseases in India, Okayama University kn-affil= en-keyword=Factor converting VBNC into culturable kn-keyword=Factor converting VBNC into culturable en-keyword=VBNC Vibrio cholerae kn-keyword=VBNC Vibrio cholerae END start-ver=1.4 cd-journal=joma no-vol=51 cd-vols= no-issue=4 article-no= start-page=243 end-page=249 dt-received= dt-revised= dt-accepted= dt-pub-year=2011 dt-pub=201110 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Enterotoxigenic Escherichia coli CS6 gene products and their roles in CS6 structural protein assembly and cellular adherence en-subtitle= kn-subtitle= en-abstract= kn-abstract=Enterotoxigenic Escherichia coli (ETEC) produces a variety of colonization factors necessary for attachment to the host cell, among which CS6 is one of the most prevalent in ETEC isolates from developing countries. The CS6 operon is composed of 4 genes, cssA, cssB, cssC, and cssD. The molecular mechanism of CS6 assembly and cell surface presentation, and the contribution of each protein to the attachment of the bacterium to intestinal cells remain unclear. In the present study, a series of css gene-deletion mutants of the CS6 operon were constructed in the ETEC genetic background, and their effect on adhesion to host cells and CS6 assembly was studied. Each subunit deletion resulted in a reduction in the adhesion to intestinal cells to the same level of laboratory E. coli strains, and this effect was restored by complementary plasmids, suggesting that the 4 proteins are necessary for CS6 expression. Bacterial cell fractionation and western blotting of the mutant strains suggested that the formation of a CssA–CssB–CssC complex is necessary for recognition by CssD and transport of CssA–CssB to the outer membrane as a colonization factor. en-copyright= kn-copyright= en-aut-name=WajimaTakeaki en-aut-sei=Wajima en-aut-mei=Takeaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SabuiSubrata en-aut-sei=Sabui en-aut-mei=Subrata kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FukumotoMegumi en-aut-sei=Fukumoto en-aut-mei=Megumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KanoShigeyuki en-aut-sei=Kano en-aut-mei=Shigeyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=RamamurthyThandavarayan en-aut-sei=Ramamurthy en-aut-mei=Thandavarayan kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ChatterjeeNabendu Sekhar en-aut-sei=Chatterjee en-aut-mei=Nabendu Sekhar kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=HamabataTakashi en-aut-sei=Hamabata en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil= kn-affil=Graduate School of Comprehensive Human Sciences, University of Tsukuba affil-num=2 en-affil= kn-affil=National Institute of Cholera and Enteric Diseases affil-num=3 en-affil= kn-affil=Graduate School of Comprehensive Human Sciences, University of Tsukuba affil-num=4 en-affil= kn-affil=Graduate School of Comprehensive Human Sciences, University of Tsukuba affil-num=5 en-affil= kn-affil=National Institute of Cholera and Enteric Diseases affil-num=6 en-affil= kn-affil=National Institute of Cholera and Enteric Diseases affil-num=7 en-affil= kn-affil=Graduate School of Comprehensive Human Sciences, University of Tsukuba en-keyword=Enterotoxigenic Escherichia coli kn-keyword=Enterotoxigenic Escherichia coli en-keyword=Colonization factor kn-keyword=Colonization factor en-keyword=CS6 kn-keyword=CS6 END