青海玉树地区草原革蜱与旱獭的蜱传病原谱研究OA

This study was aimed at characterizing the microbial communities carried by dominant tick species and investigating the prevalence of tick-borne pathogens in Nangqian County,Yushu Prefecture,Qinghai Province,China.Additionally,we sought to in-vestigate the roles of local Himalayan marmots in the cycle of transmission of tick-borne diseases,to provide a basis for the prevention and control of these diseases in the region.From 2018 to 2020,we collected questing ticks via the white flag method at Jiangxi Forest Farm,Nangqian County,Yushu Prefecture,Qinghai Province.Tick species identification was performed according to morphological characteristics and species-specific 16S rDNA assays.Meanwhile,102 Marmota himalayana were captured in the same region.Kidney and spleen tissues were aseptically dissected for analysis.Genomic DNA was extracted from 50 randomly chosen ticks and marmot kid-ney/spleen tissues.Microbial diversity in ticks was identified with high-throughput sequencing of the 16S rDNA V3-V4 hypervariable regions.On the basis of sequencing results and epidemiological data,we compared the positivity rates of the five tick pathogens carried by ticks and marmots.We collected more than 600 ticks,which were identified as Dermacentor nuttalli both morphologically and mo-lecularly.High-throughput sequencing of the 16S rDNA V3-V4 regions revealed microbial communities spanning at least 116 genera.All 50 tested ticks carried bacteria of the genera Coxiella and Rickettsia.Only 17 ticks were positive for Ehrlichia,and 14 were positive for Anaplasma.No Borrelia fragments were detected in 16S rDNA sequencing data.We identified 17 ticks positive for Borrelia burgdor-feri,46 positive for spotted fever group rickettsia(SFGR),and 3 positive for Anaplasma phagocytophilum.However,we identified only three marmots positive for B.burgdorferi and four marmots positive for A.phagocytophilum.D.nuttalli was identified as the dominant tick species in Nangqian County,Yushu Tibetan Autonomous Prefecture,Qinghai Province.SFGR and B.burgdorferi were the primary tick-borne pathogens in this region.Crucially,B.burgdorferi and A.phagocytophilum were detected in spleen and kidney tissues of Hi-malayan marmots.However,whether marmots actively contribute to the transmission cycle of tick-borne diseases in this ecosystem re-quires further investigation.