Molecular Survey Of Tick-borne Diseases In Wild Small Mammals And Dogs From Natural Protected Territory, "three Parallel River"

Objective The study was to investigate the natural infection and genetic characteristics of Borrelia burgdorferi, Anaplasma phagocytophilum, Ehrlichia sp and spotted fever group rickettsiae in wild small mammals and domestic dogs from Three Parallel Rivers Landscape,China.The results were used to monitor natural infection of mammals in mountain emerging tick-borne disease situation. Methods Wild small mammals and domestic dogs were caputured from Gaoligong mountain, Yunling mountain,Zhongdian snow mountain,Nushan mountain in the Natural Protected Territory, "Three Parallel River Region"(altitude:1000-4500m). Box traps and the cages were used to capture wild small mammals. After identification of species, the spleen was removed from each wild small mammal and stored at -196℃until tested. Domestic dog's blood samples were collected using vacuum blood extraction.Samples were transported to laboratory by low temperature freezing. All samples were tested by polymerase chain reactions (PCRs) for tick-borne agents(Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Ehrlichia sp and spotted fever group rickettsiae). Positive samples were sequenced and compared with corresponding sequences deposited in Genbank. Results A total number of 688 small mammals, which belongs to 5 orders 18 genera 40 species were collected. Among them,17 species(3 orders 10 genera) of small mammals related with three kinds of tick-borne diseases. 1)Lyme Disease (10 species in 8 genera of small mammals naturally infected with Borrelia burgdorferi, infection rate was 2.47%); 2)Human granulocytic anaplasmosis (11 species in 6 genera of small mammals naturally infected Anaplasma phagocytophilum, infection rate was 4.65%); 3)Ehrlichiosis (4 species in 3 genera of small mammals naturally infected with Ehrlichia sp, infection rate was 0.73%); The positive rate of Borrelia burgdorferi,Anaplasma phagocytophilum, Ehrlichia sp in small mammals was significant difference by theχ2 test. Spotted fever group rickettsia was not found in small mammals in this study. In addition,63 domestic dog's blood were tested.9 naturally infected with Borrelia burgdorferi. The positive rate was 14.29%.The sequence analysis showed that the B. burgdorferi s.1. in dogs all belonged to B. garinii genotypes. Anaplasma phagocytophilum, Ehrlichia sp and spotted fever group rickettsiae were not found in dogs.Conclusion Borrelia burgdorferi,Anaplasma phagocytophilum, Ehrlichia sp was firstly identified in 17 species(3 orders 10 genera) from Three Parallel Rivers Landscape,China. B. garinii was firstly identified in dogs in this areas.There were more than one tick-borne pathogen prevalence in Three Parallel Rivers Landscape,which should be paid attention by local public health authorities.