Comparative analysis of antibiotic resistance of Escherichia coli and Enterococcus from food animals in Quzhou City from 2022 to 2023
Objective To evaluate the antimicrobial resistance of bacteria in food animal in Quzhou City,Zhejiang Province from 2022 to 2023.Methods In the past two years,690 swab samples from 40 livestock and poultry farms were randomly collected,and Escherichia coli and Enterococci were separated using selective culture medium.They were then identified by polymerase chain reaction and matrix-assisted laser desorption ionization time-of-flight mass spectrometry.The minimum inhibitory concentration(MIC)of different antibiotics against these two bacteria was determined using broth microdilution method.Results In 2022,the highest antimicrobial resistance rate of Escherichia coli isolated from swab samples to tetracycline was 87.2%,with sulfamethoxazole following at 81.1%.One strain was resistant to meropenem and 5 strains were resistant to colistin.In 2023,the antimicrobial resistance rates of Escherichia coli isolated from swab samples to spectinomycin,florfenicol,trimethoprim/sulfamethoxazole,ceftiofur,and ofloxacin were all lower than those in 2022,and the antimicrobial resistance rates to meropenem and colistin were both 0%.The resistance rates of Enterococci isolated from swab samples to erythromycin,clindamycin,ofloxacin,cefotaxime,sulfamethoxazole,and tiamulin were all lower in 2023 than in 2022,while the resistance rates to penicillin,tetracycline,and linezolid were higher.No vancomycin-resistant enterococci were detected in either year.From the analysis of the antimicrobial resistance rates,MIC distribution,and antimicrobial susceptibility profiles of Escherichia coli and Enterococci over the two years,it could be concluded that both bacteria demonstrated decreased resistance to most antibiotics,with Escherichia coli showing a more significant reduction.Conclusion In 2023,the overall resistance level of Escherichia coli and enterococci of food-animal origin in the Quzhou Area has declined significantly compared to 2022.However,multi-drug resistance still exists and the spectrum of resistance is rather broad,posing a threat to food safety and human health.
food animalEscherichia coliEnterococcusantimicrobial resistanceQuzhou City