内蒙古部分地区草原革蜱携带无形体检测与进化分析

Identification and evolution analysis of Anaplasmas carried by Dermacentor nuttalli in some areas of Inner Mongolia

目的探究内蒙古地区草原革蜱无形体感染情况,鉴定蜱传无形体种属并进行系统进化分析。方法基于无形体16S rRNA基因、groEL基因和MSP4基因合成特异引物,对内蒙古地区采集的蜱虫标本进行PCR扩增,将阳性样本进行测序和分析并构建系统发育进化树。结果将采集的905只蜱虫经形态学鉴定后将168只饱血蜱与737只未饱血蜱分为220个蜱虫混合样本,经检测有41个无形体阳性样本均来自于单只饱血蜱样本,总阳性检出率为4.53%(41/905),其中呼伦贝尔地区阳性率为1.03%(3/292);赤峰地区阳性率为3.13%(17/543);鄂尔多斯地区阳性率为30%(21/70),Blast比对分析结果显示与绵羊无形体同源性高达99%以上。系统发育进化树和同源性比对分析结果显示内蒙古地区16S rRNA基因的序列与新疆绵羊无形体xjmns03(JN400674)同源性最高,为99.49%;groEL基因序列与苏丹青尼罗州绵羊无形体G-BN-40(MG383903)同源性最高,为98.77%;MSP4基因序列与与陕西绵羊无形体D/SX786(MN307493)同源性最高,为100.00%。结论内蒙古地区存在蜱传绵羊无形体,鄂尔多斯地区阳性率最高,为避免蜱传疾病对动物及人类健康造成危害,应重点对鄂尔多斯地区进行科学防控。

To explore the infection of anaplasmas carried by Dermacentor nuttalli in Inner Mongolia and determine the species and genera of anaplasmas.Based on the genes of 16S rRNA,GroEL and MSP4,the primers were synthesized to amplify ticks collected in Inner Mongolia by PCR,and then sequenced and analyzed.905 ticks were identified as Dermacentor nuttalli after morphological identification,and they were divided into 220 tick sample pools.41 positive samples were detected from single full of blood Dermacentor nuttalli pools.The total positive rate was 4.53%(41/905),of which the positive rate in Hulun Buir area was 1.03%(3/292),Chifeng area was 3.13%(17/543),Ordos Area was 30%(21/70),and the homology with Anaplasma ovis was more than 99%by Blast comparison analysis.Phylogenetic tree and homology analysis showed that the sequence of 16S rRNA gene in Inner Mongolia had the highest homology with Anaplasma ovis isolate xjmns03(JN400674)with 99.49%;the sequence of groEL gene with Anaplasma ovis isolate G-BN-40(MG383903)with the highest homology of 98.77%;The highest homology between MSP4 gene sequence and Anaplasma ovis isolate D/SX786(MN307493)was 100.00%.The infection rate of anaplasmas is relatively high in Ordos Area,and the genotype of anaplasmas is Anaplasma ovis.To avoid the harm of tick-borne diseases to human health and animals,we should focus on the scientific prevention and control of ticks in Ordos Areas.