猪源链球菌的分离鉴定及生物学特性研究

通过生化试验、药敏试验、PCR分型、毒力基因的PCR检测及动物试验对分离的猪源链球菌进行药物敏感性、血清型和分子流行病学初步研究。从不同省份猪链球菌病疑似病例猪的心血、肝、淋巴结、脑和关节液组织分离出97株链球菌,药敏试验结果表明各菌株对13种抗菌素的耐药谱不同,但对先锋霉素V和环丙沙星的耐药率均低于5%。通过对分离菌株进行PCR鉴定和分型,确认26株为猪链球菌,其中1株为1型,16株为2型,4株为7型,没有9型,另5株为其它型。进一步对1型、2型和7型猪链球菌mrp、epf和sly3种毒力基因的分布情况进行了PCR检测。动物试验表明能100%致死小白鼠的猪链球菌基因型均为epf^＋mrp^＋sly^＋2型猪链球菌,1株2型和1株7型猪链球菌均能复制出典型的猪链球菌病例。

Isolation, Identification and Biological Characterization of Streptococcus from Swine in China

Studies on drug susceptibility,serotype and molecular epidemiology of Streptococcus from swine were investigated through biochemical reaction test,drug susceptibility test,PCR typing,PCR test of virulence factor genes and animal test assays.97 strains of Streptococcus were isolated from heart blood,liver, lymph node,brain and joint of swine from different provinces in China.Drug susceptibility test for 97 strains showed their resistance patterns were different,but their drug resistance rate to cephalosporin V and ciprofloxacin is lower than 5% respectively.PCR typing assay indicated that 26 strains were Streptococcus suis including 1 serotype 1 strain,16 serotype 2 strains,4 serotype 7 strains and 5 other serotype strains.The genotypes of their mrp,epf and sly were identified by PCR method as well.Result of mouse virulence test showed that the genotypes of streptococcus,which were lethal to all of the mice,were mrp ,epf and sly serotype 2 strains.1 serotype 2 strain and 1 serotype 7 strain could reproduce typical swine streptococcosis.