表观健康猪群携带猪链球菌情况流行病学调查  

Epidemiological investigation on the carrier status of Streptococcus suis in healthy pigs

作　　者：杨珍[1,2] 王楷宬[2] 范伟兴[2] 姜平[1] 

机构地区：[1]南京农业大学动物医学院,南京210095 [2]中国动物卫生与流行病学中心,青岛266032

出　　处：《中国人兽共患病学报》2009年第10期977-979,999,共4页Chinese Journal of Zoonoses

基　　金：农业部“重大动物疫病防治关键技术引进”项目(2006-G57);公益性行业(农业)科研专项“猪链球菌病生物灾害防控技术研究与示范”项目(20080316)

摘　　要：目的了解我国不同地区表观健康猪群携带猪链球菌的情况。方法从我国20个不同地区屠宰场采集248份扁桃体,进行增菌培养后用PCR方法进行猪链球菌种型鉴定并用血清凝集试验复检,最后用多位点序列分型(Multilocus se-quence typing,MLST)系统研究各菌株之间的遗传关系。结果从248份扁桃体中共检出14株猪链球菌(检出率为5.65%),其中3株为猪链球菌2型,2株为猪链球菌7型,1株为猪链球菌9型,8株未定血清型;对6株定型菌株进行毒力因子(mrp、epf、sly、orf2、fbps、gapdh)检测发现5种毒力基因型:A1Cps2+mrp-epf+sly+orf2+fbps+gapdh+、A2Cps2+mrp-epf+sly-orf2-fbps+gapdh-、A3Cps7+mrp+epf-sly-orf2-fbps-gapdh+、A4Cps9+mrp-epf-sly-orf2-fbps+gapdh+、A5Cps7+mrp-epf-sly-orf2+fbps+gapdh+,A1和A2型的分离株为弱毒株,其他型菌株的毒力无法确定;经MLST分析,3株猪链球菌2型属于ST1,1株猪链球菌7型属于ST29,1株猪链球菌9型(CQ15)属于一个国际上未报道过的新ST型,该型被猪链球菌MLST数据库(http://ssuis.mlst.net)收录并编号为ST128。结论不同地区表观健康猪群平均带菌率为5.65%,分离到的猪链球菌2型均为弱毒株。To explore the carrier status of Streptococcus suis in healthy pigs in different area of our country, 248 samples of tonsils were collected from 20 slaughter houses in different areas of China and the type identification of S. suis was assayed by PCR after the amplification of genomic DNA in the isolates and it was further identified by serum agglutination test. Finally, the genetic relationships of isolates were investigated by multi locus sequence typing （MLST）. It was found that 14 strains of S. suis were isolated from 248 tonsil samples with a detection rate of 5.65 %, in which 3 strains were proved to be type 2, 2 strains were type 7; one strain was type 9 and 8 strains were un-typeable. To these typeable strains, virulence factors, such as mrp, epf, sly, orf2, fbps, gapdh, were detected and 5 genotypes of virulence factor could be detected; they were A1, A2, A3, A4 and A5, in which the A1 and A2 genotype isolates were proved to be weak virulent strains, while the virulenees of other genotypes were difficult to determine. As determined by MLST analysis, 3 strains of S. suis type 2 belonged to ST1 type; one strain of S. suis type 7 belonged to ST29 and one strain of S. suis type 9 was proved to be a new ST type which was not reported previously and submitted to the MLST database of S. suis （ http//ssuis, mlst, net） assigned as ST128 type.

关 键 词：猪链球菌 PCR 血清凝集试验 毒力基因型 MLST 

分 类 号：R378[医药卫生—病原生物学]