Beta-lactamase and integron-associated antibiotic resistance genes of Klebsiella pneumoniae isolated from Tilapia fishes (Oreochromis niloticus)

Tilapia fishes (Oreochromis niloticus) are commonly consumed and exported in Thailand.Bacterial isolation and drug resistance from farmed tilapia fished in Thailand were previously reported.This study was purposed to study on the distribution of human pathogenic bacteria in tilapia fishes, which were collected from Thai farms (n = 180) and fresh markets (n = 160) by identification, antibiotic susceptibility test; and conduct to identify virulence genes by molecular technique.Pathogen isolations were collected from internal organs of fish samples for identification and test of antibiotic susceptibility according to Clinical and Laboratory Standards Institute (CLSI) criteria.bla CTX-M and Int1 genes detection of antibiotic resistance bacteria was performed by molecular based techniques.Klebsiella pneumoniae, Edwardsiella tarda, and coagulase-negative Staphylococci were most frequent bacteria isolated from farming tilapia fishes, respectively.However, Escherichia coli, coagulase-negative Staphylococci, and K. pneumonia were frequently distributed from tilapia fishes in markets of Bangkok area.Klebsiella pneumoniae, E. coli, and Proteus mirabilis were resisted to penicillin and ampicillin.Klebsiella pneumoniae is the most important isolated bacteria due to the distribution in tilapia fishes and positive for bla CTX-M and Int1 gene detection.However, E. coli and P. mirabilis were lack of bla CTX-M and Int1 genes, possibly there may reserve other antibiotic resistance genes.