H3N2亚型犬流感病毒南京分离株的鉴定及遗传演化分析

Identification and genetic evolution analysis of H3N2 canine influenza virus isolated in Nanjing of China

为了解南京地区犬流感病毒的亚型,采集17只具有呼吸道症状犬的鼻咽拭子,接种SPF鸡胚分离病毒,并对分离株进行亚型鉴定和序列分析。结果,获得2株犬流感病毒,其半数鸡胚感染量(EID50)分别为10-4.54/0.1mL和10-1.42/0.1mL;血凝素(HA)基因和神经氨酸酶(NA)基因序列分析显示,2株病毒与已报道的所有H3N2亚型犬流感病毒相应序列的同源性在98%以上,但个别抗原位点有突变;遗传演化分析显示,2株病毒与近年来从犬和猫分离的犬流感病毒中国分离株及韩国分离株的亲缘关系均较近,位于同一进化分支。

In order to investigate canine influenza virus（CIV） infection in Nanjing of China, a total of 17 nasopharyngeal swabs from dogs with severe respiratory syndrome were collected from the Animal Clin- ics of Nanjing Agricultural University in 2011. Two viral strains were isolated from specific pathogen free （SPF） embryonated chicken eggs. The 50% embryo infectious doses（EID50 s） were 10^-4.54/0. 1 mL and 10^-1. 42/0.1 mL, respectively. Sequence analysis of hemagglutinin （HA） gene and neuraminidase （NA） gene showed that two CIV isolates shared high similarity（above 98%） to the known H3N2 CIV strains, but there were individual antigenic site mutations. The HA and NA genetic evolution analysis indicated that the two isolates were most similar to the newly isolated canine H3N2 viruses from dogs and cats in Korea and China,and they were in the same evolutionary branching. The result provided a foundation for further in- vestigation of biological characteristics of CIV.