Abstract

Background:
Escherichia coli (E. coli) is a common commensal bacterium in poultry, including quails, and is widely used as an indicator to monitor antimicrobial resistance (AMR) in the livestock sector. The rise of extended-spectrum β-lactamase (ESBL)–producing strains, particularly those carrying CTX-M genes, represents a major concern within the One Health context. However, data on the occurrence of CTX-M–producing E. coli in quails sold in traditional markets in Surabaya remain limited.

Aim:
This study aimed to detect CTX-M genes in E. coli isolates obtained from quail cloacal swabs from traditional markets in Surabaya and to assess their antimicrobial resistance profiles.

Methods:
A total of 100 cloacal swab samples were collected from quails in five traditional markets. Isolation and identification of E. coli were performed using EMBA, Gram staining, and biochemical tests (TSIA, SCA, SIM, MR–VP). Antimicrobial susceptibility was assessed using the Kirby–Bauer disk diffusion method following CLSI 2020 guidelines. Isolates resistant to aztreonam were further examined using PCR targeting CTX-M genes.

Results:
Of the 100 samples, 98% were confirmed as E. coli. High resistance was observed to ciprofloxacin (50%), tetracycline (33.67%), and aztreonam (20.4%). Four isolates (4.08%) demonstrated multidrug resistance. Among 20 aztreonam-resistant isolates, eight tested PCR-positive for CTX-M genes. Resistance patterns varied among markets, suggesting differing antimicrobial usage or exposure.

Conclusion:
The high prevalence of E. coli and detection of CTX-M–positive isolates indicate that traditional markets may act as reservoirs of ESBL-producing bacteria in quails. These findings underscore the need for strengthened AMR surveillance, improved hygiene practices, and One Health–oriented interventions along the quail production and distribution chain.

Key words: E. coli; ESBL; MDR; Quail; Public health.