云南省德钦县犬感染嗜吞噬细胞无形体的调查

Investigation of infection with Anaplasma phagocytophilum in dogs in Deqin,Yunan

目的了解云南省德钦县犬感染嗜吞噬细胞无形体的状况。方法对2013—2014年期间在德钦县采集的315份犬血标本，应用巢式聚合酶链反应进行嗜吞噬细胞无形体16SrRNA基因扩增和测序分析，并将所测序列与GenBank中注册的基因序列进行同源性和进化树分析。结果315份犬血样本中共有18份扩增到目的片段，总阳性率为5．71％（18／315），其中中华田园犬的阳性率为7．14％（12／168），藏犬的阳性率为5．13％（4／78），哈巴犬的阳性率为2．99％（2／67），狼犬中未检出HGA。所检出的嗜吞噬细胞无形体16SrRNA基因与GenBank中收录的部分嗜吞噬细胞无形体16SrRNA基因序列的同源性高达99％～100％。进化树分析结果显示，当地无形体分为2类流行株，将其命名为YunnanHGA1和YunnanHGA2，分别占检出菌株的16．67％和83．33％。YunnanHGA1与在乌拉圭、西伯利亚和远东地区发现的全沟硬蜱中检测到的无形体片段（HM366583）同源性为100％，YunnanHGA2与加拿大发现的肩突硬蜱中检测到的无形体片段（HG916766）同源性为99％。结论云南省德钦地区犬存在嗜吞噬细胞无形体的感染，进一步开展相应媒介、宿主及人群感染调查十分必要。

Objective To understand the prevalence of Anaplasma phagocytophilum infection in dogs in Deqin, Yunnan province. Methods A total of 315 dog blood samples were collected in Deqin from 2013 and 2014 to amplify 16S rRNA gene of A. phagocytophilum with nested polymerase chain reaction （nPCR）, the sequencing of nPCR amplification products was conducted and the results were aligned with the 16S rRNA gene sequence in GenBank. Results Among the 315 dog blood samples, 18 were positive （5.71%）. The positive rate was 7.14% （12/168） in chinese rural dog, 5.13% （4/78） in tibetan mastiff and 2.99% （2/67） in pug, no positive sample was found in wolfhond. The nucleotide sequences shared 99% - 100% similarity with those in GenBank. Two genetic types of A. phagocytophilum （Yunnan HGA1 and Yunnan HGA2） were detected, accounting for 16. 67% and 83.33% in the tested isolates respectively. Yuunan HGA1 shared 100% homology with HM366583 detected in ixodes persulcatus in Ural, Siberia and Far East of Russia, and Yunnan HGA2 shared 99% homology with HG916766 detected in ixodes scapularis in Canada. Conclusion The infection with A. phagocytophilum was detected in dogs in Deqin, it is necessary to conduct A. phagocytophilum infection survey among vectors, hosts and local population.