广东屠猪肉样品中大肠杆菌耐药性与毒力特征的分析

摘要

This study investigated the prevalence of antimicrobial resistance serotypes, virulence genes and phylogenetic background of 112 Escheriehia coil isolates from pork in Guangdong area.The O serotypes were identified by slide agglutination tests, the resistance phenotypes were tested by agar dilution.All isolates were screened for virulence genes by PCR, and the phylogenetic background determinated by multiplex PCR.Fifteen O serotypes were identified from 95 E.coli isolates, of which 065, O131, 08 and O158 were dominant serogroups.Almost all isolates were highly resistant to fiorfenieol, doxycycline, and tetracycline, but susceptible to eeftriaxone.Multiple antimierobial-resistant phenotypes (≥5 antimicrobials) were found in 79 isolates of E.coli strains.The most detectied virulence genes were stx2e and EAST1, with 38％ positive isolates carried two ormore virulence genes.The combinations of EAST1+Stx2e and hlyF+Stx2e were more than others.The majority of isolates belonged to phylogenetic group A and B1.%为分析广东地区屠猪肉中大肠杆菌(E.coli)药物敏感菌株的血清型、毒力基因和系统进化背景,本研究从屠猪肉样品中分离出112株E.coli,采用玻片凝集法鉴定血清型,琼脂稀释法测定10种抗菌药的敏感性,PCR方法检测7种毒力相关基因,多重PCR方法进行系统进化背景判定.结果显示,112株E.coli中,定型菌株95株,分别属于15种血清型,其中O65、O131、O8和O158为优势血清型.几乎所有菌株对氟苯尼考、多西环素和四环素高度耐药,而对头孢曲松高度敏感,其中多重耐药菌株多数耐5种以上药物,常见的多重耐药表型是氟苯尼考/氯霉素/多西环素/四环素/氨苄西林.PCR鉴定结果表明,含有毒力基因的菌株中38%至少具有两个毒力基因,其中EAST1+Stx2e和hlyF+Stx2e比较常见.比较常见的毒力基因为Stx2e和EAST1,STb基因仅在一株茵中检测到.多重PCR鉴定结果显示,屠猪肉样品中E.coli主要分布为共生型的A组和B1组.本研究为大肠杆菌病的控制和合理使用抗生素提供实验依据.