Diversity of Anaplasma in rodents in some areas of Yunnan province, China, 2019−2020

  Objective  To investigate the infection status of Anaplasma spp. in small mammals in Yunnan province, and provide scientific basis for the prevention and control of anaplasmosis.

  Methods  From 2019 to 2020, small mammals were captured by snap traps and rat cages in 2 counties in the west of Yunnan and 5 counties in the north of Yunnan. After morphological identification, DNA was extracted from liver and spleen tissues of small mammals, and then the 660 bp target fragment of 16S rRNA gene of Anaplasma was amplified by semi-nested PCR. The positive amplicons was sequenced, and the recovered sequence was analyzed for homology and genetic evolution.

  Results  A total of 1142 small mammals belonging to 39 species, 21 genera, 8 families, 3 orders were collected, and 21 samples from the small mammals were positive by PCR (1.84%). Among of the small mammals, 14 were infected with A. phagocytophilum, 6 were infected with A. ovis and 1 was infected with A. bovis. The positive small mammals belonging to 6 species, 3 genera, 2 families, 1 order and all were rodents. A. phagocytophilum was detected in R. brunneusculus, R. tanezumi and R. norvegicus in Menglian and Yuanmou counties. A. ovis were detected in R. brunneusculus, R. tanezumi, N. confucianus and E. miletus in Yuanmou county. A. bovis was detected in N. coxingi in Menglian county. Statistical analysis showed that there was a statistical difference in detection rate of Anaplasma in small mammals between Menglian county and Yuanmou county, and there was a statistical difference in detection rate of Anaplasma among small mammals, the detection rate was higher in N. coxingi and R. brunneusculus. No gender, age, habitat and altitude specific differences in detection rate of Anaplasma small mammals of Rodentia were observed.

  Conclusion  Many kinds of rodents in Yunnan carry a variety of anaplasmosis pathogens that can cause disease in human and domestic animals. The various hosts are mainly distributed in some areas, where the prevention and control of anaplasmosis in local people and livestock should be strengthened.