摘要
某大型鸡场的28个分场分离到的菌株,经生化检验为大肠杆菌的有87株,经O血清测定定型65株,4株自凝,18株未能定型,其中O78占20株,O1占14株,O2占5株,这些分离株中O78、O1、O2有39株占定型菌株的60.0%,因此可以认定O78、O1和O2为该大型鸡场的优势血清型,以不同场分离的菌株,以每分离株107菌落形成单位(CFU)细菌气管接种1日龄易感鸡,根据接种后7天内发生死亡和病变鸡的比例,确定出高致病株、中等致病株和低致病株分别为87.36%、8.05%和4.59%。
The purpose of this investigation was to characterize avian Eschserichia coli isolate s collected from one large farm.65out of87strains were identified as Escherichia coli isolates.Among E.coli.isolates,65strains were determined while18were not determined and4were self-aggu ltinated,which had20O 78 isolates,14O 1 isolates,5O 2 isolates,and these three isolates occupied60.0%among the65isolates.The relative pahtogenicity of serogroups Escherichia coli isolates from different factories was evaluated in susceptiable1-day-old chickens.Six birds were innoculated intratracheally with10 7 colony-forming unit(10 7 CPU)of E.coli.Based on mortality and lesions occurring during7-days period.The isolates were characterized as high,intermediate,and low pathogenicity respectively.The result suggested that87.36%are high pathogenetic,80.5%intermediate,4.59%low.
出处
《中国家禽》
北大核心
2003年第13期12-14,共3页
China Poultry
