Genotyping of extended-spectrum beta-lactamase-producing Escherichia coli isolated from wastewater of dairy farms in East Java, Indonesia.

BACKGROUND AND AIM: Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in dairy farm wastewater represents a significant threat to environmental and public health due to the dissemination of antibiotic-resistance genes. This study investigates the molecular profiles of ESBL-producing E. coli isolates harboring bla CTX-M, bla TEM, and bla SHV genes from dairy farm wastewater in East Java, Indonesia.

MATERIALS AND

METHODS

Wastewater samples (n = 342) were collected from six major dairy regions in East Java: Pasuruan, Malang, Tulungagung, Blitar, Batu, and Kediri. The samples underwent bacterial isolation, identification, and ESBL phenotypic screening using the double-disk synergy test (DDST). Molecular genotyping of bla CTX-M, bla TEM, and bla SHV was conducted using a polymerase chain reaction.

RESULTS

Of the samples, 69.30% (237/342) tested positive for E. coli, with 32.91% (78/237) identified as ESBL producers through DDST. Molecular genotyping confirmed ESBL genes in 28.20% (22/78) of the isolates. The genotypic distribution was 77.2% (17/22) bla TEM, 4.5% (1/22) bla CTX-M, 9.0% (2/22) bla TEM + bla SHV, and 9.0% (2/22) bla TEM + bla CTX-M. These findings highlight the dominance of bla TEM and the presence of multi-gene combinations in East Java's dairy farm wastewater.

CONCLUSION

The identified molecular profiles underscore dairy farm wastewater as a critical reservoir for antibiotic resistance genes, particularly bla TEM. Addressing this issue necessitates stringent antimicrobial use policies, improved wastewater management, and enhanced biosecurity measures. These findings support a One Health approach to mitigate environmental and public health risks associated with AMR.