Farm environments: Reservoir for Multidrug‐Resistant and Virulent Escherichia coli in Bangladesh

Farm environments, especially dairy and poultry farms, are the major sources of multidrug‐resistant (MDR) pathogenic Escherichia coli . At present, knowledge regarding the prevalence of MDR E. coli , phylogroup, and pathotype in various farm environments of Bangladesh is inadequate. Highlighting the issue, the present investigation was carried out to determine the prevalence of MDR E. coli , phylogroup distribution, and pathotype diversity in various farm environments. Thirteen types of samples were collected from poultry, dairy, and aquaculture in Cumilla, Bangladesh, during three seasons (rainy, summer, and late autumn). Following identification by cultural, biochemical, and molecular techniques, the isolates were investigated for AMR profile, ESBL production, biofilm‐forming capability, antibiotic resistance, virulence and adhesin genes, and phylogroup pattern. Sixty‐three E. coli isolates, mostly from dairy and poultry, were identified from the collected samples. Among the 19 antibiotics tested, resistance to ciprofloxacin (55.54%) was the most common, whereas all the isolates were sensitive to ceftazidime (30  μ g). The MAR index and the percentage of MDR isolates were higher in the rainy season samples than in the summer. Between sources, the prevalence of MDR isolates was more common in poultry (78.79%) than in cattle farms (25%). Poultry isolates showed a significantly higher frequency of antibiotic resistance genes than dairy isolates ( p − value < 0.05). In the biofilm‐forming phenotypic test, 93.7% of the isolates were biofilm formers. The biofilm‐forming ability was higher in Phylogroup B1 than in Phylogroup C ( p − value < 0.05). Among the phylogroups, B1 (73.02%) was the most common, followed by C (19.02%) and A (3.17%). Almost 50.7% of isolates were pathogenic with EHEC (34.92%) being most prevalent. The most common resistance genes were tetA , qnrS , sul-2 , dfrA17 , dfrA1 , blaSHV , and blaTEM . These results emphasize the need for focused surveillance and mitigation efforts to control the spread of MDR E. coli in farm environments, especially in poultry.