Molecular detection of genes encoding resistance to tetracycline and determination of plasmid-mediated resistance to quinolones in avian pathogenic Escherichia coli in Sukabumi, Indonesia

Aim: This study aimed to identify genes encoding resistance to tetracycline (TE) and plasmid-mediated resistance to quinolones in Escherichia coli isolates from clinical cases of avian colibacillosis in Sukabumi, Indonesia. Materials and Methods: A total of 25 E. coli archive isolates were collected in 2013-2017 from clinical cases of avian colibacillosis in Sukabumi, Indonesia. All isolates were tested for TE and quinolone resistance using the disk diffusion method. TE-resistant E. coli isolates were screened for the presence of tet(A) and tet(B) genes by single polymerase chain reaction (PCR). The qnr(A). qnr(B), and qnr(S) genes were detected by multiplex PCR in quinolone-resistant E. coli isolates. Results: Result of this study shows that 19 of 25 (76%) E. coli isolates arc resistant to oxytetracycline and 64% arc resistant to TE; among them, 63.2% and 31.5% were positive tet(A) and tet(B), respectively. 13 out of 25 (52%) are resistant to ciprofloxacin and 36% are resistant to enrofloxacin either norfloxacin; among them, 61.6% were positive qnr(A), 7.7% were positive qnr(B), 23% were positive qnr(S), and 7.7% were positive both of qnr(A) and qnr(S). Conclusion: This study shows that a few pathogens of E. coli am resistant to TE and quinolone. The frequency of tet and qnr genes that are responsible for this resistance among avian pathogenic E. coli isolates in Sukabumi, Indonesia, was high.