Distribution of extended-spectrum β-lactamase producing Escherichia coli genes in an integrated poultry-fish farming system in Bogor, Indonesia.

Background and aim: The excessive use of antimicrobials in livestock farming leads to the emergence and dissemination of antimicrobial-resistant organisms. This study aimed to detect extended-spectrum β-lactamase (ESBL)-producing Escherichia coli genes in integrated poultry-fish farms in Bogor, Indonesia.

Materials and methods: A total of 256 samples were collected from six poultry-fish farms. One hundred and seventy-five chicken cloaca swabs, 60 fish skin swabs, six pond water samples, and 15 farmer's hand swabs. ESBL-producing E. coli was confirmed through double-disk diffusion. The specific primers and probe genes for quantitative polymerase chain reaction detection of ESBL-producing E. coli targeted blaTEM, blaCTX-M, blaSHV, and blaOXA-48 genes.

Results: Among the 256 samples tested, 145 (56.6%) were positive for E. coli, and 67.6% (98/145) were identified as ESBL-producing E. coli. The most ESBL-producing E. coli isolates were obtained from chicken cloaca (78.3%, 72/92), followed by pond water (66.7%, 4/6), fish skin (47.6%, 20/42), and farmer's hand swabs (40%, 2/5). About 100% of the isolates carried the genes blaTEM and blaCTX-M, whereas 17.3% and 24.5% carried blaSHV and blaOXA-48, respectively.

Conclusion: ESBL-producing E. coli genes were investigated in chicken cloaca, fish, pond water, and farmers' hands within an interconnected poultry-fish farming operation. The ESBL-producing E. coli in chickens can transfer resistant genes to aquatic environments. The transfer could harm other aquatic species and food chains, potentially threatening human health.