食源性沙门氏菌分离株致病性研究和毒力相关基因检测

Foodborn Salmonella Isolates: Pathogenicity Evaluation and Detection of Virulence Genes

为研究零售鲜肉源沙门氏菌(Salmonella)优势血清型分离株的致病性及相关毒力基因的相关性,本研究分别取4种优势血清型S.derby、S.agona、S.enteritidis、S.typhimurium沙门氏菌分离株对SPF级昆明小鼠进行致病性实验,采用改良寇氏法计算半数致死量,判断4种血清型沙门氏菌的毒力,并通过聚合酶链式反应检测实验菌株中9种毒力相关基因的分布情况并分析其相关性。结果表明,4种不同血清型的沙门氏菌分离株对小鼠均有40%~70%的致死率,S.enteritidis、S.agona、S.derby对昆明小鼠的致病力相似,S.typhimurium较弱,且发现致病力的强弱与毒力岛SPI-2中的sse L基因密切相关。

The purpose of this study was to evaluate the pathogenicity of the predominant serotypes of Salmonella isolated from retail fresh meat and the relationship between the pathogenicity and virulence genes.The pathogenicity of the dominant serotypes including S.agona,S.derby,S.enteritidis and S.typhimurium against specific pathogen free(SPF)Kunming mice was evaluated by improved Karber’s method,and the distribution of 9 virulence genes was detected by polymerase chain reaction(PCR).The results demonstrated that four predominant Salmonella serovars showed high mortalities of up to 40%?70%.S.enteritidis,S.agona and S.derby had similar pathogenicity,while weaker pathogenicity was observed for S.typhimurium.The pathogenicity of Salmonella was associated with the sseL gene on Salmonella pathogenicity island(SPI-2).