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

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. Yunnan 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.