China antimicrobial resistance surveillance network for pets (CARPet), 2018 to 2021

Abstract China Antimicrobial Resistance Surveillance Network for Pets (CARPet) was established in 2021 to monitor the resistance profiles of clinical bacterial pathogens from companion animals. From 2018 to 2021, we recovered and tested 4,541 isolates from dogs and cats across 25 Chinese provinces, with Escherichia coli (18.5%) and Staphylococcus pseudintermedius (17.8%) being the most predominant bacterial species. The Enterobacterales were highly susceptible to tigecycline, meropenem, colistin, and amikacin (70.3%–100.0%), but showed moderate resistance to ampicillin, ceftriaxone, doxycycline, florfenicol, levofloxacin, enrofloxacin, and trimethoprim-sulfamethoxazole (29.3%–56.7%). About 66.3% of Acinetobacter spp. were resistant to florfenicol, with relatively low resistance to another 11 antibiotics (1.2%–23.3%). The Pseudomonas spp. showed high susceptibility to colistin (91.7%) and meropenem (88.3%). The coagulase-positive Staphylococcus spp. showed higher resistance rates to most antimicrobial agents than coagulase-negative Staphylococcus isolates. However, over 90.0% of Staphylococcus spp. were susceptible to linezolid, daptomycin and rifampin, and no vancomycin-resistant isolates were detected. E. faecium isolates demonstrated higher resistance rates to most antimicrobial agents than E. faecalis isolates. Streptococcus spp. isolates showed low resistance to most antimicrobial agents except for doxycycline (78.2%) and azithromycin (68.8%). Overall, the tested clinical isolates showed high rates of resistance to commonly used antimicrobial agents in companion animals. Therefore, it is crucial to strengthen the monitoring of bacterial resistance in pets. By timely and effectively collecting, analyzing, and reporting antimicrobial resistance dynamics in pets, the CARPet network will become a powerful platform to provide scientific guidance for both pet medical care and public health.