2015—2022年河南省食品和临床鼠伤寒沙门菌及单相鼠伤寒沙门菌的耐药特征比较分析

Comparative analysis of antimicrobial resistance of Salmonella enterica serovar typhimurium and its monophasic variant in food and clinical patients in He’nan Province from 2015 to 2022

目的 了解2015-2022年河南省临床和食品来源的鼠伤寒沙门菌和单相鼠伤寒沙门菌的流行情况和耐药特征。方法 对2015-2022年河南省食品和临床分离的399株鼠伤寒沙门菌疑似菌株进行血清复核和药敏实验,采用血清凝集法和多重荧光PCR方法进行血清分型,采用微量肉汤稀释法进行抗生素药物的敏感试验,耐药性比较采用χ^(2)检验。结果 399株鼠伤寒沙门菌疑似菌株中包含单相鼠伤寒沙门菌225株(56.39%),鼠伤寒沙门菌174株。两种沙门菌对氨苄西林、氯霉素和四环素的耐药率较高,均达到50%以上。2017年开始出现对亚胺培南和甲氧苄啶/磺胺甲噁唑的耐药菌株,单相鼠伤寒沙门菌对氨苄西林和庆大霉素的耐药率高于鼠伤寒沙门菌,差异有显著性(P<0.05)。鼠伤寒沙门菌对头孢唑啉的耐药率高于单相鼠伤寒沙门菌,差异有显著性(P<0.05),两种沙门菌对3类及以上抗生素耐药率达到60%以上,共同多重优势耐药谱为耐氨苄西林-氯霉素-甲氧苄啶/磺胺甲噁唑-四环素。结论 单相鼠伤寒沙门菌检出率略高于鼠伤寒沙门菌,成为河南省鼠伤寒沙门菌临床分离株的优势血清型,两种沙门菌均普遍耐药且多重耐药现象严重,应加强监测单相鼠伤寒沙门菌的耐药情况和食品来源鼠伤寒沙门菌的检出情况,防止菌株进一步扩散。

Objective To study the prevalence and antimicrobial resistance characteristics of Salmonella enterica serovar typhimurium(S.typhimurium)and monophasic S.typhimurium from clinical patients and food in Henan Province from 2015 to 2022.Methods Three hundred and ninety-nine strains of Salmonella from food and clinical patients in Henan Province were serotyped according to the Kauffmann White scheme by slide agglutination and multiplex real-time PCR method.Microbroth dilution method was used to test antimicrobial resistance of S.typhimurium.Statistical analysis was carried out using Chi‑square test.Results Three hundred and ninety-nine strain were composed of two hundred twenty-five monophasic S.typhimurium(56.39%)and one hundred seventy-four S.typhimurium.The imipenem and trimethoprim/sulfamethoxazole resistant isolates were found since 2017.The antimicrobial resistance rate of two Salmonella strains to ampicillin,chloramphenicol and tetracycline was higher,reaching more than 50%.The antimicrobial resistance rate of monophasic S.typhimurium to ampicillin and gentamicin was significantly higher than that of S.typhimurium(P<0.05).The resistance rate of S.typhimurium to cefazolin was significantly higher than that of monophasic S.typhimurium(P<0.05).Two serotypes of S.typhimurium were resistant to over 60%of three classes or more antimicrobial agents.The common multiple dominant antimicrobial resistance spectrum was ampicillinchloramphenicol-trimethoprim/sulfamethoxazole-tetracycline pattern.Conclusion Monophasic S.typhimurium had replaced S.typhimurium as predominant serotype in clinical patients in Henan Province.Two serotypes of S.typhimurium strains are generally antimicrobial resistant and the multi-antimicrobial resistance patterns serious.In order to make effective interventions and reduce the spread of S.typhimurium.The study results suggest that the detection rate of foodborn S.typhimurium should be strengthen as well as the antimicrobial resistance of monophasic S.typhimurium.