{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T06:01:38Z","timestamp":1777442498068,"version":"3.51.4"},"reference-count":30,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2021,7,2]],"date-time":"2021-07-02T00:00:00Z","timestamp":1625184000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"Prevalence of toxigenic Vibrio cholerae<\/jats:italic> O1 in aquatic reservoirs in Bangladesh apparently increases coinciding with the occurrence of seasonal cholera epidemics. In between epidemics, these bacteria persist in water mostly as dormant cells, known as viable but non-culturable cells (VBNC), or conditionally viable environmental cells (CVEC), that fail to grow in routine culture. CVEC resuscitate to active cells when enriched in culture medium supplemented with quorum sensing autoinducers CAI-1 or AI-2 which are signal molecules that regulate gene expression dependent on cell density. V<\/jats:italic>. cholerae<\/jats:italic> O1 mutant strains with inactivated cqsS<\/jats:italic> gene encoding the CAI-1 receptor has been shown to overproduce AI-2 that enhance CVEC resuscitation in water samples. Since V<\/jats:italic>. cholerae<\/jats:italic> non-O1 non-O139 (non-cholera-vibrios) are abundant in aquatic ecosystems, we identified and characterized naturally occurring variant strains of V<\/jats:italic>. cholerae<\/jats:italic> non-O1 non-O139 which overproduce AI-2, and monitored their co-occurrence with V<\/jats:italic>. cholerae<\/jats:italic> O1 in water samples. The nucleotide sequence and predicted protein products of the cqsS<\/jats:italic> gene carried by AI-2 overproducing variant strains showed divergence from that of typical V<\/jats:italic>. cholerae<\/jats:italic> O1 or non-O1 strains, and their culture supernatants enhanced resuscitation of CVEC in water samples. Furthermore, prevalence of V<\/jats:italic>. cholerae<\/jats:italic> O1 in the aquatic environment was found to coincide with an increase in AI-2 overproducing non-O1 non-O139 strains. These results suggest a possible role of non-cholera vibrios in the environmental biology of the cholera pathogen, in which non-O1 non-O139 variant strains overproducing AI-2 presumably contribute in resuscitation of the latent pathogen, leading to seasonal cholera epidemics. Importance<\/jats:bold>. Toxigenic Vibrio cholerae<\/jats:italic> which causes seasonal epidemics of cholera persists in aquatic reservoirs in endemic areas. The bacteria mostly exist in a dormant state during inter-epidemic periods, but periodically resuscitate to the active form. The resuscitation is enhanced by signal molecules called autoinducers (AIs). Toxigenic V<\/jats:italic>. cholerae<\/jats:italic> can be recovered from water samples that normally test negative for the organism in conventional culture, by supplementing the culture medium with exogenous AIs. V<\/jats:italic>. cholerae<\/jats:italic> belonging to the non-O1 non-O139 serogroups which do not cause cholera are also abundant in natural waters, and they are capable of producing AIs. In this study we characterized V<\/jats:italic>. cholerae<\/jats:italic> non-O1 non-O139 variant strains which overproduce an autoinducer called AI-2, and found that the abundance of the cholera pathogen in aquatic reservoirs correlates with an increase in the AI-2 overproducing strains. Our results suggest a probable role of these variant strains in the environmental biology and epidemiology of toxigenic V<\/jats:italic>. cholerae<\/jats:italic>, and may lead to novel means for surveillance, prevention and control of cholera.<\/jats:p>","DOI":"10.1371\/journal.pone.0254068","type":"journal-article","created":{"date-parts":[[2021,7,2]],"date-time":"2021-07-02T18:09:20Z","timestamp":1625249360000},"page":"e0254068","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":8,"title":["Environmental prevalence of toxigenic Vibrio cholerae O1 in Bangladesh coincides with V. cholerae non-O1 non-O139 genetic variants which overproduce autoinducer-2"],"prefix":"10.1371","volume":"16","author":[{"given":"Iftekhar Bin","family":"Naser","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1347-1739","authenticated-orcid":true,"given":"Tushar Ahmed","family":"Shishir","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6316-1459","authenticated-orcid":true,"given":"Shah Nayeem","family":"Faruque","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M. 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