鸡大肠埃希氏菌致病性、菌毛表达及血凝特性

STUDY ON PATHOGENICITY,FIMBRIA EXPRESSION AND HEMAGGLUTINATION CHARACTERISTICS OF AVIAN Escherichia coli ISOLATES

观察比较了鸡大肠埃希氏菌某些分离株腹腔接种、气管接种对1日龄鸡的致病性，研究了在体外不同培养条件下，菌株菌毛的表达情况、菌株的血凝谱及血凝特性。结果表明，菌株经腹腔接种及气管接种途径对鸡的致病性一致；致病性与菌毛有关，具有致病性的菌株，在体外经37℃72h培养，均能表达菌毛，其中大部分菌株表达Ⅰ型菌毛，对鸡不具有致病性的菌株在体外不表达菌毛；不同菌株的血凝谱及血凝方式具有一定的差异，大部分菌株的血凝能被D-甘露糖抑制，表现为甘露糖敏感型血凝（MSHA）。还分析了菌株血凝谱与致病宿主之间的关系。

Some strains of avian E. coli were studied with respect to their pathogenicity to one-day-old chickens inoculated via abdomenal and trachea,hemagglutination(HA) scope,HA characteristics and fimbria expression in different culture conditions. The results revealed that the pathogenicity of E. coli isolates to one-day-old chickens after abdominal inoculation accorded with that after tracheal inoculation; the pathogenicity was related with the fimbriae which were only expressed by the isolates showing pathogenicity to one-day-old chickens;the majority of these strains expressed F 1 (type I )fimbriae and exhibited mannose-sensitivehemagglutination (MSHA); the HA scopes and HA characteristics of various isolates were different. Besides these,the relation between HA scope and host animal was also discussed in this paper.