一株不表达K88、K99、987P粘附因子牦牛肠毒素型大肠杆菌的分离鉴定

Isolation and Identification of a K88, K99, 987P Adhesin negative Enterotoxigenic Escherichia coli Isolated from Yak

从西藏地区腹泻死亡牦牛中分离出一株肠毒素型大肠杆菌。该菌在形态特征、培养特性和生化特性方面与大肠杆菌基本一致。血清学试验表明 ,该菌的O抗原属O148,K88、K99、987P单因子血清均不能凝集本菌。在MSHA反应中 ,本菌能凝集绵羊、豚鼠、马、鸡的红细胞 ,而K88、K99、987P抗血清均不能抑制其对绵羊、豚鼠、马、鸡红细胞的凝集。腹腔接种对小白鼠具有高致病性。乳鼠胃内投服试验和兔回肠结扎试验证明 ,该菌能产生热稳定肠毒素和热敏性肠毒素。总之 ,该菌是一株不表达K88、K99、987P的、能产生ST和LT的肠毒素型大肠杆菌。

A enterotoxigenic Escherichia coli was isolated from died yak with diarrhea in Tibet area. The strain had almost the same morphological, cultural and biochemical characteristics as Escherichia coli . The serotype of the strain was O148. The isolate did not react with antiserum specific for K88, K99 and 987P. The strain had the ability to hemagglutinate erythrocytes of sheep, gunia pig, horse and chicken in mannose sensitive hemagglutination test. Moreover, the hemagglutination activity with the erythrocytes above by the isolate was not inhibited by antiserum to K88, K99 and 987P respectively. Pathogenicity for KM mice was high through abdominal injection. The strain was able to produce the heat stable enterotoxin as well as the heat labile enterotoxin as revealed in the sucking mouse test and rabbit ileum test. These fact suggested that the strain be an ETEC strain of bearing no K88, K99 and 987P fimbriae adhesins.