天津地区猪链球菌9型分离株致病性的研究  

Study on pathogenicity of Streptococcus suis serotype 9 strains from Tianjin of China

作　　者：董志民[1,2,3] 李秀丽 田向学[1,2,3] 杨春蕾 燕晓翠[4] 谭世旭 张万江[5] 刘思国 鄢明华 DONG Zhi-min;LI Xiu-li;TIAN Xiang-xue;YANG Chun-lei;YAN Xiao-cui;TAN Shi-xu;ZHANG Wan-jiang;LIU Si-guo;YAN Ming-hua(Tianjin Animal Science and Veterinary Research Institute,Tianjin 300381,China;Tianjin Scientific Observation Experiment Station for Veterinary Medicine and Diagnosis Technology,the Ministry of Agriculture of the People`s Republic of China,Tianjin,300381,China;Tianjin Engineering Research Center for Livestock and Poutry Health Breeding,Tianjin 300381,China;Lutai No.1 Middle School of Ninghe District in Tianjin,Tianjin 301500,China;Division of Bacterial Diseases,State Key Laboratory of Veterinary Biotechnology,Harbin Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Harbin 150069,China)

机构地区：[1]天津市畜牧兽医研究所,天津300381 [2]农业部兽用药物与诊断技术天津科学观测实验站,天津300381 [3]天津市畜禽健康养殖技术工程中心,天津300381 [4]天津市宁河区芦台第一中学,天津301500 [5]中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/动物细菌病研究室,黑龙江哈尔滨150069

出　　处：《中国兽医科学》2019年第11期1397-1405,共9页Chinese Veterinary Science

基　　金：十三五国家重点研发计划项目（2017YF0500102）;中国农业科学院重大平台推进计划项目（Y2017PT50）;天津市生猪产业技术体系病毒病防控岗位项目（ITTPRS2017003）

摘　　要：猪链球菌是引起人和动物发生猪链球菌病的主要病原,给养猪业带来巨大的经济损失,并严重危害人类公共卫生安全。本实验室从天津地区212个养猪场送检的470份临床病料中分离鉴定出8株9型猪链球菌,通过昆明小鼠LD50测定试验、PCR方法分析菌株携带的主要毒力基因、黏附力试验和溶血性试验等,对分离株的致病能力、基因特性、黏附能力和溶血能力等进行了研究。结果显示,8株9型猪链球菌分离株对昆明小鼠的LD50差异较大,最小值6.4×10^6 CFU/mL,最大值为5.7×10^8 CFU/mL;受试菌株中gdh、cps9J、gapdh、fbps、orf2、mrp、sly和ef基因的检出率依次为100.0%、100.0%、62.5%、50.0%、37.5%、0.0%、0.0%和0.0%,分为5种毒力基因型,毒力基因型与菌株对昆明鼠的致病能力无直接关系。8株9型猪链球菌对PK-15细胞均具有黏附作用,黏附能力为1.2×10^3~3.9×10^4CFU/mL,其中CHTJS55菌株最强,CHTJS9-ZL次之,CHTJS72S最弱。溶血性试验结果表明,随着孵育时间的增长,各菌株的溶血能力均增强,且孵育3 h时,CHTJS41菌株的溶血能力最强,CHTJS70菌株最弱。上述研究结果为临床制定合理、有效的猪链球菌病防控措施以及候选疫苗株的筛选提供了参考依据。Streptococcus suis is the major pathogen in human and animals,and it can bring huge economic losses to the breeding industry and have caused serious harm to human public health security.To clarify pathogenicity related characteristics,our laboratory technicians collected 8 isolates of Streptococcus suis serotype 9 from the 470 clinical samples from 212 farms,by Kunming mice LD50 test,PCR method for virulence genes,adhesion ability test,and hemolysis ability test,etc.The results of Kunming mice LD50 test showed that the LD50 values of 8 strains of Streptococcus suis type 9 were significantly different,with the minimum value(LD50 of CHTJS9-ZL was 6.4×10^6 CFU/mL)and the maximum value(CHTJS72 and CHTJS72S were 5.7×10^8 CFU/mL)and both of them had a 100-fold difference.The results of detection of virulence genes showed that the detection rates of gdh,cps9J,gapdh,fbps,orf2,mrp,sly and ef genes in 8 isolates were 100.0%,100.0%,62.5%,50.0%,37.5%,0.0%,0.0%and 0.0%,respectively.These isolates were classified into 5 virulence genotypes,and virulence genotypes of strains had no direct relationship with the pathogenicity of Kunming mice.The results of adhesion test showed that 8 strains had adhesion to PK-15 cells,and the value between 1.2×103 and 3.9×10^4 CFU/mL was the result of adhesion ability,among which CHTJS55 strain was the strongest and CHTJS9-ZL was the second one,and CHTJS72S was the weakest,in this study.The hemolytic test showed that the hemolysis ability of each strains increased with the increase of incubation time,and the CHTJS41 strain had the strongest hemolysis ability and the CHTJS70 strain was the weakest when incubated for 3 h.These study resuts laid the foundation for further development of the pathogenic mechanism of Streptococcus suis serotype 9 strains,and provided a reference for the clinical development of reasonable and effective prevention and control measures for Streptococcus suis and screening of candidate vaccine strains.

关 键 词：猪链球菌9型 致病性 黏附能力 溶血性 毒力基因 

分 类 号：S852.612[农业科学—基础兽医学]