东阳市一例人感染猪链球菌病的病原学及分子生物学鉴定分析

Analysis and identification of pathogenic and molecular biologic of human Streptococcus suis infection in Dongyang

目的:对东阳市一例人感染猪链球菌病的分离株进行病原学及分子生物学鉴定,以了解其生物学特性。方法:将患者血液和脑脊液进行增菌培养,并对分离的菌株进行涂片染色形态观察、rapid ID 32 STREP试条生化鉴定、药敏试验、PCR技术检测分离株的种属特异性基因、毒力基因及89K候选致病岛特异基因片段。结果:仅从患者的脑脊液中分离出病原菌,经rapid ID 32 STREP试条鉴定为猪链球菌Ⅱ型(id=99.9%,T=0.89;极好鉴定结果)并从该分离株检测到种属特异性基因tuf和16SrRNA;cps2J、mrp、sly、gapdh和ef等毒力基因;89K(1&2)、89K(3&4)、89K(5&6)候选致病岛特异基因片段。结论:该患者是由SS2引起的,且该分离株属强毒株。

Objective：The isolated strains of human Streptococcus suis infection from patient in Dongyang were identified by pathogenic and molecular biologic methods to study the biological characteristics. Methods： Specimens of blood and CSF from patient were collected for microbiologic culture. Then the isolated strains were detected by smear and morphology, biochemical test with Rapid ID Strep32, drug sensitivity test and PCR to identify the specific genes of species - virulent genes and DNA fragment of 89K candidate pathogenicity. Results：Strains were isolated from the patient＇s CSF specimen, and they were diagnosed as Streptococcus suis serotype 2 （SS2） by biochemical test with Rapid ID Strep32 （id = 99.9%, T = 0. 89, excellent results of the identification）. Species - specific tuf andl6S rDNA, 89K sequence, and virulent genes, including cp2J, sly, gapdh, and ef, were detected. Conclusion：The patient was caused by SS2 and the virulence of the isolated strain was very strong.