Dynamics, Diversity, and Virulence of . in Homestead Pond Water in Coastal Bangladesh.

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 spp. The bacterial counts showed bi-modal annual growth peak, pre- and post-monsoon, strongly correlating ( < 0.0005) with temperature. Of 200 isolates characterized, bv. sobria (27%) was predominant among co-existent (20%), (17%), (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 bv. sobria, , and . Pathogenic strains were distinguishable by possessing at least three of the major virulence genes: , and , together with accessory virulence factors. PFGE of I-digested genomic DNA revealed high genetic diversity and distant lineage of potentially toxigenic clones. Therefore, along with increased global warming, 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.