2021年8月珠海一起食源性疾病暴发事件中金黄色葡萄球菌病原学特征分析  

Pathogenic characteristics of Staphylococcus aureus isolates from a foodborne disease outbreak in Zhuhai City in August,2021

作　　者：方艳梅[1] 龙冬玲 京舒娉 陈晶京 杨春晓[1] 黄辉涛 黄利群[1] 黄开松 FANG Yanmei;LONG Dongling;JING Shuping;CHEN Jingjing;YANG Chunxiao;HUANG Huitao;HUANG Liqun;HUANG Kaisong(Microbiology Lab,Zhuhai Center for Disease Control and Prevention,Guangdong Zhuhai 519064,China;Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics,Guangdong Medical University,Guangdong Dongguan 523822,China)

机构地区：[1]珠海市疾病预防控制中心微生物检验所,广东珠海519064 [2]广东医科大学广东省医学分子诊断重点实验室,广东东莞523822

出　　处：《中国食品卫生杂志》2024年第6期735-740,共6页Chinese Journal of Food Hygiene

基　　金：广东省科技计划(2021B1212030002)。

摘　　要：目的研究一起食源性疾病事件金黄色葡萄球菌(金葡菌)病原学特征和同源性。方法采用国标方法分离鉴定病原菌,微量肉汤稀释法检测菌株对16种药物的敏感性,全基因组测序和生物信息学分析病原菌分子遗传特征和同源性。结果该事件分离得到16株金黄色葡萄球菌,包括8株患者分离株,1株厨工分离株和7株食品分离株。MLST和Spa分型结果为ST7-t91、ST5-t548、ST398-t588和ST965-t62,患者株分为ST7-t91型和ST5-t548型;ST7分离株均对四环素和青霉素耐药,携带耐药基因aadD、te(t K)、blaZ和lnu(A),ST5株对16种抗生素均敏感;cgMLST分析发现ST7型菌株间等位基因差异≤3;毒力基因注释发现ST7株携带sea、chp、scn和sak毒力基因,ST5株携带chp、scn、sak、seg、selk、selm、selo和seln毒力基因。结论该事件由多个ST型金葡菌混合感染引起,以ST7-t91型为主,该克隆株致病力强,但对头孢类抗生素和喹诺酮类等临床一线抗生素敏感。Objective To characterize the pathogenic characteristics and homology of Staphylococcus aureus(SA)isolated from a foodborne outbreak.Methods A selection medium was applied to culture the possible infectious agent according to national standard methods,and the micro broth dilution method was applied to determined the isolate’s sensitivity to 16 drugs.Whole genome sequencing and bioinformatics analysis were employed to investigate the isolates’molecular genetic characteristics and homology.Results A total of 16 SA strains were isolated in this outbreak,including eight strains isolated from patients,one from the kitchen worker,and seven from food.MLST and Spa typing analysis identified five distinct types in this outbreak,namely ST7-t91,ST5-t548,ST398-t588 and ST965-t62,in which the ST7-t91 and ST5-t548 types account for strains from humans;All ST7 isolates were resistant to tetracycline and penicillin,carrying resistance genes aadD,tet(K),blaZ,and lnu(A)respectively,while the ST5 strain was sensitive to all tested antibiotics;cgMLST analysis revealed that the difference of these ST7 strains was less than three loci.Gene annotation revealed that ST7 strains contained the sea,chp,scn,and sak virulence genes,while ST5 possessed chp,scn,sak,seg,selk,selm,selo,and seln genes.Conclusion This outbreak was caused by mixed infections of multiple ST types of SA,with ST7-t91 as the predominant type,and this clone present a high pathogenicity and was sensitive to somefirst-line clinical antibiotics tested,such as cephalosporins and quinolones.

关 键 词：食源性疾病 金黄色葡萄球菌 全基因组测序 cgMLST 肠毒素 

分 类 号：R155[医药卫生—营养与食品卫生学]