中国畜牧兽医2019，Vol.46Issue(1)：80-88,9.DOI:10.16431/j.cnki.1671-7236.2019.01.010
猪链球菌4型分离株生物学特性研究
Study on Biological Characteristics of Streptococcus suis Type 4 Isolates
摘要
Abstract
In order to analyze the pathogenic biological characteristics of Streptococcus suis type 4 (SS4) .10 strains of SS4 from different regions in China were subjected to multilocus sequence typing.Seven conserved housekeeping genes aroA, gki, dpr, mutS, recA, thrA and cpn60 of Streptococcus suis were amplified by PCR.The sequencing results were uploaded to MLST database to find the sequence type, and the clustering analysis map was constructed to clarify the genetic relationship in strains.The seven major virulence genes gdh, mrp, epf, sly, fbps, gapdhand orf2 were identified by PCR, and the distribution of virulence factors of SS4 was analyzed by virulence factor spectrum.BALB/c mice were subjected to animal pathogenicity test with 10 strains ofpurified bacteria, and the strongest strains were selected according to the lethal number of mice and subjected to New Zealand rabbit pathogenicity test.The results of multilocus sequence typing showed that 6strains were ST850, 3strains were ST1006, and 1strain was ST94.According to the location analysis, the strains in Guangdong and Jiangsu had high homology, and the strains in Jiangsu and Shanghai showed differentiation, which showed genetic diversity.gdh, gapdh and orf2 genes were detected in 10 strains, slygene was detected in 7strains, and fbps gene were detected in 4strains.According to the virulence factor spectrum, a total of 3virulence genotypes were found, 6strains were gdh+sly+gapdh+orf2+type, 3strains were gdh+fbps+gapdh+orf2+type, and 1strain was gdh+sly+fbps+gapdh+orf2+type.Animal pathogenicity test results showed that 10 strains could all cause the death of BALB/c mice.The LD50 of SH1510was as low as 1×108 CFU, which was the most pathogenic to mice, and SH1510 could cause typical neurological symptoms and death in New Zealand rabbits.The above results provided new data for the genetic evolution and virulence studies of Streptococcus suis, which had enriched the study of Streptococcus suis.关键词
猪链球菌4型(SS4)/多位点序列分型/毒力因子/致病性Key words
Streptococcus suis serotype 4 (SS4) /MLST/virulence factor/pathogenicity分类
农业科技引用本文复制引用
孙珂,何孔旺,倪艳秀,祝昊丹,王丹丹,关琳,俞正玉,周俊明,吕立新,王春凤..猪链球菌4型分离株生物学特性研究[J].中国畜牧兽医,2019,46(1):80-88,9.基金项目
公益性行业(农业)科研专项经费(201303041) （农业）
江苏省生猪产业技术体系生物安全创新团队(SXGC(2017)263) （SXGC(2017）
