四川省松潘县牦牛体表蜱、高原鼠兔携带巴尔通体和无形体的PCR检测与进化分析

旨在了解四川省松潘县牦牛体表蜱、高原鼠兔巴尔通体和无形体感染情况。采集牦牛体表的蜱和捕获高原鼠兔,对蜱进行形态学初步鉴定后,提取蜱和高原鼠兔脾总DNA,PCR扩增蜱16S rRNA、巴尔通体rpoB和无形体16S rRNA基因,对PCR产物阳性产物测序、比对及构建系统进化树,从而确定蜱种类及蜱和高原鼠兔感染巴尔通体和无形体的种类及感染率。结果显示:在松潘县进安乡、山巴乡、下八寨乡各采集到蜱102、97和131只,共计330只,经鉴定均为青海血蜱。蜱巴尔通体仅检出1种巴尔通体,与B.melophagi亲缘关系最近,进安乡、山巴乡和下八寨乡检出率分别为16.7%、8.2%和18.3%,其中下八寨乡检出率显著高于进安乡(P<0.05);蜱源无形体进安乡、山巴乡和下八寨乡检出率分别为9.8%、12.4%和26.7%,下八寨乡检出率显著高于进安乡(P<0.01),检出的无形体均为1种,与牛无形体(A.bovis)亲缘关系最近;下八寨乡检出的鼠兔源巴尔通体与B.queenslandens亲缘关系最近,感染率为6.7%;进安乡、山巴乡和下八寨乡检出的鼠兔源巴尔通体与B.grahamii亲缘关系最近,感染率分别为8.7%、17.9%和13.3%,3个点检出率无显著差异;未定种Bartonella sp.(MN296294)和Bartonella sp.(MN296293)仅分别在进安乡和下巴乡检出;与蜱均检出无形体不同,高原鼠兔均未检出无形体。此外,蜱和高原鼠兔均未发现2种及2种以上病原混合感染。松潘县青海血蜱携带巴尔通体和无形体,高原鼠兔感染巴尔通体,且首次在高原鼠兔体内检测到疑似B.queenslandens的病原体,提示当地居民有感染这两类病原风险。

PCR Detection and Phylogenetic Analysis of Bartonella spp. and Anaplasma spp. in Ixodid Ticks Collected from Yak and Plateau Pika in Songpan County of Sichuan Province

This study aimed to investigate Bartonella and Anaplasma infection in ticks and plateau pika in Songpan county of Sichuan province. Plateau pikas were trapped and the ticks collected from yaks were classified by morphological identification. The total DNA of ticks and Plateau pika spleens was extracted, partial sequences of 16S rRNA of ticks and Anaplasma, and rpoB gene of Bartonella were amplified by PCR, respectively. The positive products were sequenced and compared through the NCBI database. Phylogenetic trees were constructed based on 16S rRNA and rpoB for determination species of ticks, Anaplasma and Bartonella, respectively. A total of 330 ticks were collected from 3 villages and only Haemphysalis qinghaiensis was found. As for tick samples, the infection rates of Bartonella of Jinan, Shanba, and Xiabazhai were 16.7%,8.2%, and 18.3%, respectively and only B. melophagi was detected. Compared with Jinan village, the infection rate of Bartonella in Xiabazhai was higher (P<0.05); The infection rates of Anaplasma in Jinan, Shanba, and Xiabazhai were 9.8%, 12.4%, and 26.7%, respectively and only A.bovis was detected. Compared with Jinan, the infection rate of Anaplasmain Xiabazhai was higher (P<0.01); As for plateau pika, B. grahamii was detected in Jinan, Shanba, and Xiabazhai with infection rates of 8.7%, 17.9%, and 13.3%, respectively, and no significant difference observed. B. queenslandens was detected only in Xiabazhai with an infection rate of 6.7%; Bartonella sp. (MN296294) and Bartonella sp. (MN296293) were detected in Jinan and Xiabazhai, respectively. No Anaplasma spp. were detected in plateau pika and no co-infection was observed in tick and plateau pika. In Songpan, H. qinghaiensis is biological vector of Anaplasma and plateau pika being a reservoir host of Bartonella spp. B. queenslandens was detected firstly in plateau pika and there exists a risk of human infection.