Characterization of beta-lactamase and biofilm producing Enterobacteriaceae isolated from organized and backyard farm ducks

This study was undertaken to detect the occurrence of beta-lactamase and biofilm producing Enterobacteriaceae in healthy ducks. A total 202 cloacal swabs were collected from ducks kept in organized (n = 92) and backyard (n = 110) farms in West Bengal (India). The ducks had no history of antibiotic intake. Among the 87 phenotypically beta-lactamase producing Escherichia coli, 19 (17 center dot 43%), 6 (5 center dot 05%) and 15 (13 center dot 76%) isolates possessed bla(TEM), bla(SHV) and bla(CTX-M) respectively. Whereas, 5 (38 center dot 46%) Salmonella isolates were found to harbour bla(CTX-M). In K. pneumoniae 10 (33 center dot 33%), 3 (13 center dot 33%), 4 (13 center dot 33%) isolates possessed bla(TEM), bla(SHV) and bla(CTX-M) respectively. The sequences of selected PCR products were found 98% cognate with bla(CTX-M-9,) bla(SHV-12) and bla(TEM-1). Beta-lactamase producing E. coli isolates belonged to 14 different serogroups such as O1, O2, O3, O5, O7, O8, O35, O83, O84, O88, O119, O128, O145 and O157. Moreover, 87 E. coli (79 center dot 82%), six Samonella (46 center dot 15%) and 13 K. pneumoniae (43 center dot 33%) isolates were detected as AmpC producers possessing bla(AmpC). Majority of E. coli (46 center dot 79%), Salmonella (46 center dot 15%) and K. pneumoniae (70%) isolates were detected as biofilm producers and possessed the associated genes (csgA, sdiA, rcsA, rpoS). Significantly higher occurrence of beta-lactamase and biofilm producing Enterobacteriaceae isolates was detected in backyard ducks than organized farms. Significance and Impact of the Study Consumption of antibiotic through feed or during therapy is considered as potential reason for generation of antimicrobial resistant bacteria in birds. This study provides valuable evidence that exposure to contaminated environment may be an additional source for generation of antimicrobial resistant bacteria in backyard ducks. The backyard ducks are reared by marginal farmers in India who cannot offer antibiotics to them either through feed or during therapy due to high cost. The study also reveals a significant correlation between biofilm formation and possession of antimicrobial resistance genes in the bacterial isolates from the ducks.