ABSTRACT
<p><b>OBJECTIVE</b>To investigate the prevalence of Anaplasma phagocytophilum in small mammals from the forest area of Hengduan Mountains in southwestern China.</p><p><b>METHODS</b>Small mammals captured from Gaoligong and Xianggelila mountainous area of Yunnan province were detected by PCR amplification. The sequences of 16S rRNA and Msp4 gene fragments from positive samples were compared with corresponding sequences deposited in GenBank.</p><p><b>RESULTS</b>A total number of 436 small animals, which belongs to 5 orders 18 genera 35 species were tested, 32 (7.34%) were positive in 6 genera 11 species. There were 8.64% (26/301) positive in 25 species at Goligong mountainous areas, and 4.44% (6/135) were positive in 19 species at the Xianggelila mountainous areas. Positive small mammals were most rodents. The nucleotide sequences of A.phagocytophilum 16S rRNA gene amplified from small mammals varied from 99% - 100% and were 99% - 100% similar with the corresponding segments of A. phagocytophilum from Jilin deposited in GeneBank. The sequences of A. phagocytophilum Msp4 gene showed that there was 95% - 97% similarity with the corresponding sequences registered in GenBank.</p><p><b>CONCLUSION</b>A. phagocytophilum was firstly identified in 6 genera 11 species small mammals from a forest area of Hengduan Mountainous areas in southwestern China. Rodents might serve as the primary hosts indicating the potential risk to the domestic animals and human beings in this area.</p>