AUTHOR=Dey Subarna Sandhani , Hossain Zenat Zebin , Akhter Humaira , Jensen Peter K. M. , Begum Anowara 

TITLE=Abundance and biofilm formation capability of Vibrio cholerae in aquatic environment with an emphasis on Hilsha fish (Tenualosa ilisha)

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.933413

DOI=10.3389/fmicb.2022.933413

ISSN=1664-302X

ABSTRACT=<p>The potentially deadly and sporadic diarrhea-causing agent, <italic>Vibrio cholerae</italic>, is present in a great number in the freshwater aquatic environment and can be transmitted to humans by different aquatic organisms. In the perspective of Bangladesh, an anadromous fish species Hilsha (<italic>Tenualosa ilisha</italic>) can act as a transmission vehicle of <italic>V. cholerae</italic> from the aquatic to the household kitchen environment. The present study was carried out to investigate the presence of <italic>V. cholerae</italic> in the aquatic habitat of Bangladesh with a major emphasis on freshly caught Hilsha fish, along with river water and plankton samples from the fish capture site. The study also detected the biofilm formation capability of <italic>V. cholerae</italic> within Hilsha fish that might help the transmission and persistence of the pathogen in aquatic habitat. Twenty out of 65 freshly caught fish (30.8%) and 1 out of 15 water samples (6.67%) showed the presence of <italic>V. cholerae</italic> and none of the plankton samples were positive for <italic>V. cholerae</italic>. The isolated strains were identified as non-O1 and non-O139 serogroups of <italic>V. cholerae</italic> and contain some major toxin and virulence genes. A few strains showed cellular cytotoxicity on the HeLa cell line. All strains were able to form biofilm on the microtiter plate and the detection of three genes related to biofilm formation (<italic>vpsA</italic>, <italic>vpsL</italic>, and <italic>vpsR</italic>) were also assayed using qPCR. In this study, the <italic>in vitro</italic> biofilm formation ability of the isolated strains may indicate the long-term persistence of <italic>V. cholerae</italic> in different parts of Hilsha fish. The abundance of <italic>V. cholerae</italic> only in freshly caught Hilsha fish and the absence of the pathogen in the surrounding aquatic environment could stipulate the role of Hilsha fish as one of the major transmission routes of <italic>V. cholerae</italic> from the freshwater aquatic environment of Bangladesh to the household kitchen environment.</p>