Comparison of Drug Resistance of Escherichia coli Isolated from Livestock and Poultry in Pudong New Area and Songjiang District of Shanghai from 2016 to 2023
To investigate the trends in drug resistance of Escherichia coli(E.coli)from livestock and poultry in Pudong New Area and Songjiang Districts of Shanghai(hereafter referred to as the"two districts")from 2016 to 2023,this study collected 401 and 490 anal swab samples from livestock and poultry farms in the two districts,respectively.E.coli isolates were identified,and the antimicrobial usage on these farms was surveyed.The drug susceptibility of the isolated E.coli strains against 14 antimicrobial agents across 10 classes was determined using the broth microdilution method.The results showed that antimicrobial usage varied across farms in the two districts.A total of 333 and 350 E.coli isolates were obtained from the two districts,with isolation rates of 83.04%and 71.43%,respectively.High resistance rates were observed for tetracycline(87.09%,82.00%),sulfisoxazole(77.78%,82.00%),ampicillin(82.58%,70.30%),and trimethoprim/sulfamethoxazole(70.87%,76.90%).Low resistance rates were found for ceftazidime(6.61%,6.90%)and colistin(0.90%,0.90%),and no resistance to meropenem was detected.Multidrug-resistant strains accounted for 87.99%and 81.71%of isolates,respectively.Over the eight years,the overall resistance rates,proportion of multidrug-resistant strains,and resistance spectrum breadth showed a declining trend,with a more significant reduction in Songjiang District.These findings indicate that E.coli from livestock and poultry in Pudong New Area and Songjiang Districts exhibit high resistance rates to certain antimicrobials and severe multidrug-resistant issues.However,under the framework of antimicrobial reduction policies,the drug resistance levels have shown improvement,with Songjiang District experiencing a more substantial decrease.
Escherichia colidrug resistanceveterinary antimicrobial drugsreduction actionPudong New AreaSongji-ang District