人猪链球菌感染性综合征研究

Studies on human streptococcal infectious syndrome caused by infected pigs

目的 描述人 猪链球菌感染性综合征的临床表现 ,探讨病原特征 ,以及感染来源。方法 观察 2 5例原因不明的“急性感染性中毒性出血性休克综合征” ,用十几种培养基进行病原分离、菌种鉴定、药敏试验和动物试验 ,用PCR指纹图技术分析人源与猪源株的同源性 ,用流行病学方法调查感染来源等。结果 猪链球菌感染性综合征临床表现主要有 :链球菌中毒性休克综合征和链球菌脑膜炎型综合征。从患者的血液和脑脊液中各分离到 3株链球菌 ,经生长培养特性 ,形态特征 ,生化特性 ,菌体脂肪酸分析 ,血清凝集等系统鉴定 ,此 6株菌均为猪链球菌Ⅱ型。经流行病学调查等证实 ,本起疾病为感染性疾病 ,人与人之间未见传染性 ,与接触患病、死猪有关。随机引物PCR技术分析显示 ,人源与猪源菌株系同源。结论 本起疾病的病原体为猪链球菌Ⅱ型 ,感染来源为直接接触病。

Objectives To demonstrate the clinical manifestations of S suis infectious syndrome; to study the characteristics of causative organism and its source Methods 25 cases of unknown causes of food poisoning were identified in the central area of Jiangsu province, China in July 1998 Biological specimens was collected in some patients, and the causative organism was isolated using a number of different culture medium Isolated organisms were identified by serum antibody tests, API biochemical tests, drug sensitivity tests and animal model experiments The human born strains and the pig born strains were compared by RAPD technique Epidemiological methods were applied to trace the source of causative organisms Results Cases were clinically categorized into two types: Streptococcal toxic shock syndrome (STSS) and streptococcal meningitis syndrome(SMS) Three strains of streptococci were isolated respectively from the blood and cerebrospinal fluid of 6 cases All these 6 strains were confirmed to be S suis type 2 by culture characteristics, morphology, biochemical characteristics, serum antibody tests and fatty acid profile analysis Animal model experiment showed that these strains were sensitive to rabbits and pigs, but not to rats RAPD fingerprint test revealed an identity between human born and pig born strains Conclusions The aetiological agent of these human cases was S suis type 2 Human cases were contracted by direct contact with the infected pigs or the corpse of infected pigs