摘要
目的研究汉中地区零售鸡肉源性耐甲氧西林金黄色葡萄球菌(MRSA)分离、耐药及分子流行特征,为食源性感染的预防提供线索。方法采集汉中市售鸡肉样品196份,进行MRSA的分离鉴定,抗菌药物敏感性试验联合全基因组测序技术对分离出的MRSA菌株进行耐药特征、ST分型、毒力基因、全基因组进化树分析。结果MRSA分离率为18.9%(37/196),药敏结果显示,对青霉素、红霉素、克林霉素、四环素、庆大霉素耐药率超过50%。共识别到4个ST型,ST9(40.5%,15/37)、ST59(37.8%,14/37)、ST398(13.5%,5/37)、ST5(8.1%,3/37),以ST9型和ST59型菌株为优势株,与ST59型菌株相比ST9型肠毒素基因簇携带率高;ST59型耐药基因携带较少,免疫逃逸毒力基因sak-scn携带率高;ST398型不携带肠毒素基因;ST5型携带毒力基因种类最多。共检出23种毒力基因,所有菌株均携带溶血毒素基因(hlgA、hlgB、hlgC)和金属蛋白酶基因(aur),新型肠毒素的携带率高于传统型肠毒素,杀白细胞素基因和胞外酶基因也被检出。进化树显示相同ST型的菌株聚类为相同的分支。结论ST9型是汉中地区2019—2024年鸡肉源性MRSA分离率最高的菌株类型,肠毒素基因簇携带率高;同时ST59型也逐渐成为本地区零售鸡肉中流行的优势克隆,其免疫逃逸基因携带率高。
Objective To clarify the prevalence,drug resistance,and epidemiological characteristics of methicillinresistant Staphylococcus aureus(MRSA)isolated from chicken meat in Hanzhong,and provide useful insights for prevention of foodborne infections.Methods A total of 196 retail chicken samples were collected from Hanzhong for isolation and identification of Staphylococcus aureus and MRSA.Antimicrobial susceptibility testing combined with wholegenome sequencing was used to analyze antimicrobial resistance characteristics,perform sequence typing(ST),and identify toxin genes.The phylogenetic relationships among MRSA strains identified in this study were analyzed.Results The MRSA detection rate was 18.9%(37/196).More than 50% of these methicillin-resistant strains showed resistance to penicillin,erythromycin,clindamycin,tetracycline,and gentamicin.A total of four STs[(ST9(40.5%,15/37),ST59(37.8%,14/37),ST398(13.5%,5/37),and ST5(8.1%,3/37)]were detected.ST9 and ST59 were the dominant clones identified in this study.The ST9 strain exhibited a higher prevalence of enterotoxin gene clusters than the ST59 strain,which carried fewer drug resistance genes but demonstrated a higher prevalence of the immune escape virulence genes sak and scn.Notably,the ST398 strain lacks enterotoxin genes,whereas the ST5 strain harbors the most diverse repertoire of virulence genes.In total,23 virulence genes were identified.All strains carried the hemolysin genes hlgA,hlgB,hlgC,and the metalloproteinase gene aur.The prevalence of novel enterotoxins was higher than that of traditional enterotoxins.Genes encoding leukocidin and exoproteinases were also identified.The phylogenetic analysis reveals that strains sharing the same ST type are consistently grouped into a single clade within the evolutionary tree.Conclusion The ST9 strain exhibited the highest isolation rate among chicken-associated MRSA in the Hanzhong region between 2019 and 2024,and was characterized by a high prevalence of enterotoxin gene clusters.During this period,the ST59 strain became the predominant clone in retail chickens in this region,with its notably high prevalence of immune escape genes.
作者
余瑶
辜依海
翁蕊
侯轩
王辉
陶浚齐
邓明惠
牟建
张微
YU Yao;GU Yihai;WENG Rui;HOU Xuan;WANG Hui;TAO Junqi;DENG Minghui;MOU Jian;ZHANG Wei(Department of Microbiology,3201 Hospital,Shaanxi Hanzhong 723000,China;Zhejiang University,Zhejiang Hangzhou 310058,China)
出处
《中国食品卫生杂志》
北大核心
2025年第5期438-445,共8页
Chinese Journal of Food Hygiene
关键词
食源性菌株
耐甲氧西林金黄色葡萄球菌
耐药性
毒力基因
Foodborne strains
methicillin-resistant Staphylococcus aureus
antimicrobial resistance
virulence genes
作者简介
余瑶,女,主管检验师,研究方向为病原生物学,E-mail:yy15769206849@126.com;通信作者:张微,女,副主任技师,研究方向。
