AUTHOR=Sadique Abdus , Neogi Sucharit Basu , Bashar Tanvir , Sultana Marzia , Johura Fatema-Tuz , Islam Saiful , Hasan Nur A. , Huq Anwar , Colwell Rita R. , Alam Munirul 

TITLE=Dynamics, Diversity, and Virulence of Aeromonas spp. in Homestead Pond Water in Coastal Bangladesh

JOURNAL=Frontiers in Public Health

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2021.692166

DOI=10.3389/fpubh.2021.692166

ISSN=2296-2565

ABSTRACT=<p>Aeromonads are aquatic bacteria associated with frequent outbreaks of diarrhea in coastal Bangladesh, but their potential risks from environmental sources have remained largely unexplored. This study, over 2 years, examined homestead pond waters in the region for monthly dynamics and diversity of <italic>Aeromonas</italic> spp. The bacterial counts showed bi-modal annual growth peak, pre- and post-monsoon, strongly correlating (<italic>p</italic> &lt; 0.0005) with temperature. Of 200 isolates characterized, <italic>Aeromonas veronii</italic> bv. sobria (27%) was predominant among co-existent <italic>Aeromonas schubertii</italic> (20%), <italic>Aeromonas hydrophila</italic> (17%), <italic>Aeromonas caviae</italic> (13%), and three more. PCR screening of virulence-related genes identified 15 genotypes (I to XV), however, enterotoxigenicity in animal model was observed for five genotypes, ca. 18% (nine of 50) strains, prevalent in <italic>A. veronii</italic> bv. sobria, <italic>A. hydrophila</italic>, and <italic>A. caviae</italic>. Pathogenic strains were distinguishable by possessing at least three of the major virulence genes: <italic>ascV, hlyA, ela, ast</italic>, and <italic>alt</italic>, together with accessory virulence factors. PFGE of <italic>Xba</italic>I-digested genomic DNA revealed high genetic diversity and distant lineage of potentially toxigenic clones. Therefore, along with increased global warming, <italic>Aeromonas</italic> spp. having multi-factorial virulence potential in coastal ponds that serve as drinking water sources pose a potential health risk, and underscores the need for routine monitoring.</p>