猪链球菌2型四川分离株猪体回归试验

Experimental Infection with Isolates of Streptococcus suis 2 in Sichuan Province

选用35～38日龄的健康断奶仔猪21头，分3组，用2005四川分离株SSsc0501分别经静脉、肌肉注射和口服3种途径感染，进行猪体回归试验。肌肉注射组（含菌0．6×10^8个／mL）16h开始出现症状，至36h全部死亡，发病率、病死率均为100％；静脉注射组（含菌0．2×10^8个／mL）25h开始出现症状，48h内全部死亡，发病率和病死率均为100％；口服攻毒组（含菌2×10^8个／mL）90h后开始有发病症状，第9天有1头死亡，发病率75％，病死率33％。从感染病死猪的肝脏、脾脏、肾脏、心血、大脑、脑脊液、淋巴结、肺脏和关节液中均分离到链球菌，经鉴定为试验攻毒的目的菌，表明猪体能够很好地用于猪链球菌2型动物感染模型，同时说明该菌侵害器官广泛，为进一步探讨该病的综合防制提供了重要技术依据。

SSsc0501 ,a strain of Streptococcus suis serotype 2 ,isolated through the 2005 outbreak in Sichuan province was inoculated to 3 groups of a month-old weaned pigs via introvenous,intramuscular or oral route to observe clinical and pathological changes after infection. Symptom was appeared at 16 h,and all died after 36 h in the intramuscular group（0.6×10^8个/mL.）, both morbidity and mortality were 100%. Symptom was appeared at 25 h and all died after 48 h in the introvenous group（0.2 ×10^8个/mL）,both morbidity and mortality were 100% ,too. Symptom were appeared at 90 h and one pig died after 9 days in oral route group （2 ×10^8个/mL）, morbidity and mortality was 75 % and 33 %, respectively. Pathogens isolated from viscera in experimental pigs were identificated to be Streptococcus suis serotype 2,which is the same with the inoculates. The result showed that weaned pigs can be successfully used as animal experimental models of Streptococcus suis 2,and the pathgens make inroad the various organs,thereby provides scientific basis for comprehensive precaution for Streptococcus suis 2.