云南省思茅地区啮齿动物多杀巴斯德菌分离株毒力测定

Detection of virulence of Pasteurella multocida isolates from wild rodents in Yunnan

目的 对2016年云南省思茅区大面积野鼠死亡事件中分离的多杀巴斯德菌的毒力进行测定。方法 选取在死亡野鼠中分离并经分子鉴定为血清型A型和F型的2株多杀巴斯德菌,采用常规的动物接种试验对2株菌及其混合菌(1∶1)接种Balb/C小鼠,计算各组的半数致死量(LD_(50))。结果 A血清型和F血清型多杀巴斯德菌株及其混合菌株对Balb/C小鼠的LD50分别为1.1×10^(2)、5.0×10^(6)、5.8×10^(2)。经统计学分析,A血清型菌株毒力最强,F血清型菌株毒力低于A血清型菌株,也低于混合菌株接种组。结论 该疫情分离到的A血清型和F血清型多杀巴斯德菌株对Balb/C小鼠具有较强的毒力,尤其A血清型菌株属于强毒型多杀巴斯德菌。

Objective To understand the virulence of Pasteurella multocida isolates from the wild rodents in a rodent epidemic in Simao of Yunnan province in 2016. Methods Two strains of P. multocida were isolated from dead wild rodents,which belonged to serotype A and F by molecular typing. Balb/C mice were inoculated with the two strains and their mixture(1∶1) by routine challenge test, and the median lethal dose(LD50) of each group was calculated. Results The LD_(50) of P. multocida serotype A, serotype F strains and their mixture to Balb/C mice were 1.1×10^(2), 5.0×10^(6) and 5.8×10^(2). By statistical analysis, the virulence of serotype A strain was strongest, and the virulence of serotype F strain was lower than that of serotype A strain and the mixture. Conclusion P. multocida serogroup A and F strains isolated in this rodent epidemic had strong virulence to Balb/C mice, especially serotype A strain, belonging to very virulent P. multocida.