石家庄市猪链球菌分离鉴定及快速诊断方法研究

Study on Isolation and Identification and the Rapid Detection for Streptococcosis Suis in Different District of Shijiazhuang

从石家庄市地区各县市猪场送检的疑似病例中分离得到72株猪源链球菌,选择其中具有一定区域、特定致病类型的代表性菌株18株,进行了病原分离和分群鉴定,并与标准株进行了对比试验.初步证实本地区流行菌株仍以兰氏分群C群及D群居多,以C群链球菌为主占50%,但D群有上升趋势占33.3%,此外还出现1株G群占5.6%,另有2株未定群的猪链球菌,其分布无明显的地域性.为检测石家庄地区SS分离株的毒力因子,选取了猪链球菌8种主要毒力因子基因,设计并合成8对引物,用PCR方法进行检测.结果显示:已知21株SS2菌株中90.5%表现为cps2/gdh+/gapdh+/ef+/mrp+/sly+/fbps+/orf2+;送检的疑似SS2的病例中,仅有10%左右表现为cps2/gdh+/gapdh+/ef+/mrp+/sly+/fbps+/orf2+.可见,石家庄地区的猪链球菌与国内其他地区SS2分离株的基因型不同,表明石家庄目前SS2的主要流行菌株是具有部分毒力因子的弱毒菌株.

First of all,from those suspicious samples in hose from the different district of Shijiazhuang,72 positive samples which by the direct microscopical check and sample culture microscopical check are gotten.Through its isolation,those of 18 typical separating trunks are identified and show that the cause of the disease of streptococcus in Shijiazhuang focuses on C group（50 %）,D group（33.3 %）,G group（5.6 %） and two unidentified strains,and with its no obvious distribution figure.To investigate the distribution of virulence associate factors of Streptococcus suis（SS）,8 virulence factors are selected to be detected by PCR assay.The results show that 21 virulent isolates of SS2 in the different district of China are detected.The positive detection rates of cps2/gdh＋/gapdh＋/ef＋/mrp＋/sly＋/fbps＋/orf2＋ are 90.5 %;the results show the distribution of virulent associate factors of virulent streptococcus suis in Shijiazhuang is different from isolates of the other district of China.The virulence associate factors profile is conform,which suggest that only the 10 % strains of SS2 in Shijiazhuang is virulent stains which have all 8 virulence factors,the most part of strains of SS2 in Shijiazhuang is low virulent stains which do not have all 8 virulence factors.