猪链球菌血清9型菌株分离鉴定及强毒株筛选  

Isolation,Identification and Screening of Virulent Strains of Streptococcus suis Serotype 9

作　　者：李倩倩 梁巩 刘锦锦 金清 龙云志 杨柳 黄英 余道兵 宋文博 黄超 汤细彪 LI Qian-qian;LIANG Gong;LIU Jin-jin;JIN Qing;LONG Yun-zhi;YANG Liu;HUANG Ying;YU Dao-bing;SONG Wen-bo;HUANG Chao;TANG Xi-biao(Wuhan Keqian Biological Co.,Ltd,Wuhan,Hubei,430000,China)

机构地区：[1]武汉科前生物股份有限公司,湖北武汉430000

出　　处：《动物医学进展》2022年第7期6-13,共8页Progress In Veterinary Medicine

基　　金：湖北省技术创新专项重大项目(2018ABA109)。

摘　　要：为了筛选猪链球菌血清9型(SS9)强毒株并研究其生物学特性,对全国各地发病猪的病料中进行猪链球菌分离培养。通过形态学观察、革兰氏染色镜检、PCR鉴定及血清型分型确定了29株猪链球菌血清9型菌株,分别命名为SS9-1~SS9-29。通过玉米大蜡螟幼虫和Balb/c小鼠对29株猪链球菌血清9型菌株进行初筛和复筛,筛选出2株猪链球菌血清9型强毒株,分别为SS9-20、SS9-22。为进一步了解SS9-22的生物学特性,对其进行生长曲线绘制、毒力基因检测及小鼠致病性试验。结果显示,SS9-22菌株在37℃培养6 h时,菌液密度可达到最高值。毒力基因检测发现SS9-22的毒力基因型为gapdh^(+)/sly^(+)/fbps^(^(+))/orf2^(+)/mrp﹣/89K﹣/gdh^(+)/epf^(+)。SS9-22菌株经腹腔接种Balb/c小鼠,24 h内可引起小鼠精神萎靡、扎堆、被毛耸立、运动迟缓、死亡等临床症状,该菌株的LD50为3.2×10^(7)CFU,表明该菌株为强毒株。研究结果丰富了猪链球菌的菌种库,为猪链球菌血清9型的防控提供研究材料,为后续猪链球菌9型的致病机制研究及疫苗的开发奠定了基础。In order to screen the virulent strains of Streptococcus suis serotype 9 and study its biological characteristics,Streptococcus suis was isolated and cultured from diseased pigs all over the country.Through morphological observation,Gram staining microscopy,PCR identification and serotyping,29 strains of Streptococcus suis serotype 9 were identified and named SS9-1-SS9-29,respectively.Through preliminary screening and re-screening in Galleria mellonella and Balb/c mice,the most virulent strains SS9-20 and SS9-22 was screened.To further understand the biological characteristics of SS9-22,its growth curve,virulence genes and mouse pathogenicity were evaluated.The growth curve showed that the strain reached its peak when cultured at 37℃for 6 hours.Virulence gene testing showed that genotype of SS9-22 was gapdh^(+)/sly^(+)/fbps^(+)/orf2^(+)/mrp﹣/89K﹣/gdh^(+)/epf^(+).SS9-22 was intraperitoneally inoculated to Balb/c mice,and within 24 hours,it could cause the mice to suffer from malaise,get together,stand up hair,slow movement,death and other clinical symptoms.The LD50 is 3.2×10^(7)CFU,indicating that the strain is virulent.The research results enriched the strain library of different serotypes of Streptococcus suis,and laid the foundation for subsequent research on the pathogenic mechanism of Streptococcus suis serotype 9 and the development of vaccines.

关 键 词：猪链球菌9型 分离鉴定 毒力基因 致病性试验 

分 类 号：S852.611[农业科学—基础兽医学] S858.28[农业科学—兽医学]