Antimicrobial susceptibility profiles of Escherichia coli and Enterococcus spp. isolated from companion animals in Indonesia.

This study aimed to investigate the antimicrobial susceptibility profile in Escherichia coli and Enterococcus spp. isolated from healthy cats and dogs in Indonesia. A total of 186 rectal swab samples were individually collected from June to October 2025 at 13 animal clinics from three regions. Bacterial isolation was performed using selective agar media, and the species was confirmed by polymerase chain reaction. In this study, we obtained 71 of 164 (43.3%) antimicrobial-resistant (AMR) E. coli and 53 of 94 (56.4%) AMR enterococci by disc diffusion test. The highest resistance of E. coli was observed for ampicillin (36.6%), followed by streptomycin (21.3%), tetracycline (15.9%), cefazolin (13.4%), nalidixic acid (12.8%), cefotaxime (11.0%), gentamicin (11.0%), aztreonam (8.5%), doxycycline (8.5%), chloramphenicol (7.9%), sulfamethoxazole-trimethoprim (6.7%), amoxicillin-clavulanic acid (3.7%), ciprofloxacin (3.0%) and enrofloxacin (2.4%). On the other hand, the highest resistance of enterococci was identified for tetracycline (24.5%), followed by high-level streptomycin (21.3%), erythromycin (21.3%), ciprofloxacin (10.6%), enrofloxacin (9.6%), penicillin (7.4%), linezolid (6.4%), ampicillin (5.3%), fosfomycin (4.3%) and chloramphenicol (3.2%). Multidrug-resistant (MDR) E. coli was detected in 44 of 164 (26.8%) isolates, which were dominated by extraintestinal pathogenic strains (phylogroup B2 and D), while MDR enterococci were detected from 13 of 94 (13.8%) isolates. Our study offers valuable insights into the resistance profiles of Indonesian companion animals. A continuous monitoring strategy for AMR is needed to control the development of AMR bacteria in companion animals.