Molecular identification of the blaTEM gene in Escherichia coli isolated from quail in Surabaya

Abstract

Antimicrobial resistance (AMR) represents a major global public health concern driven in part by extensive antibiotic use in food-producing animals. Poultry production, including quail farming, plays a significant role in the dissemination of resistant bacteria due to intensive management systems and frequent antimicrobial exposure. Escherichia coli, a common intestinal commensal and opportunistic pathogen, is widely used as an indicator organism for monitoring AMR, particularly extended-spectrum β-lactamase (ESBL) production mediated by genes such as blaTEM. However, data on ESBL-associated resistance in quails marketed in Indonesia remain limited. This study aimed to detect the presence of the blaTEM gene in E. coli isolated from quails sold in traditional markets in Surabaya, Indonesia. A total of 150 cloacal swab samples were collected from five traditional markets between November and December 2024. Isolation and identification of E. coli were performed using conventional bacteriological and biochemical methods. Antimicrobial susceptibility testing was conducted using the Kirby–Bauer disk diffusion method in accordance with CLSI guidelines. Polymerase chain reaction (PCR) was used to detect the blaTEM gene among aztreonam-resistant isolates. E. coli was isolated from 148 of 150 samples (99%). The highest resistance rates were observed against ciprofloxacin (33.1%), tetracycline (22.2%), and aztreonam (13.5%), while resistance to kanamycin and chloramphenicol remained low. Multidrug-resistant (MDR) E. coli was identified in 2.7% of isolates. PCR analysis revealed the presence of the blaTEM gene in five aztreonam-resistant isolates, confirming the circulation of ESBL-associated resistance. These findings indicate that quails marketed in traditional markets may serve as reservoirs of antimicrobial-resistant E. coli. Continuous surveillance, prudent antimicrobial use, and improved hygiene practices are essential to mitigate the spread of ESBL-producing bacteria within a One Health framework.