内蒙古大兴安岭林区牙克石段的蜱种及蜱携病原体感染调查

Investigation of tick species and pathogen infection status in the Yakeshi Section of the Greater Khingan Mountains,Inner Mongolia,China

目的调查内蒙古东部大兴安岭林区牙克石段的蜱种分布及病原体感染状况。方法2016-2019年,在东部林区蜱活跃高峰期(5-6月)采用布旗法采集游离蜱标本,使用体视显微镜对蜱初步分类;提取蜱全基因组DNA,采用斑点热立克次体、无形体属、埃立克体属、莱姆病螺旋体和新型回归热螺旋体病原体的特异性基因进行PCR检测。结果本次共采集蜱虫2786只,通过体视显微镜和基因检测分析,隶属于1科3属4种,分别为全沟硬蜱(Ixodes persulcatus)、嗜群血蜱(Haemaphysalinae concinna)、日本血蜱(Haemaphysalinae japonica)、森林革蜱(Dermacentor silvarum)。其中,全沟硬蜱(78.6%,2191/2786)、嗜群血蜱(15.9%,442/2786)为本地区的优势蜱种。在大兴安岭林区牙克石段的7个采样地区的蜱中,乌奴耳镇斑点热立克次体检出率最高,为74.2%(222/299);博克图镇无形体属检出率较高,为18.9%(39/206);库都尔镇埃立克体属、莱姆病螺旋体、新型回归热螺旋体的检出率均较高,分别为26.1%(12/46)、76.1%(35/46)、13.0%(6/46)。除新型回归热螺旋体外,其他4种病原体的检出率雄蜱均高于雌蜱(P<0.05);成蜱的无形体、埃立克体、莱姆病螺旋体检出率均高于幼蜱(P<0.05)。大兴安岭林区牙克石段蜱的复合感染率为19.5%(544/2786)。其中,免渡河镇蜱携2种病原体复合感染率为40.6%(186/458),乌奴耳镇蜱携3种及以上病原体复合感染率分别是47.4%(36/76)、90%(9/10)。结论大兴安岭林区牙克石段共存在4种蜱,蜱携莱姆病螺旋体最普遍,其中免渡河镇和乌奴耳镇的蜱普遍携带多种病原体,需重点加强该地区蜱媒传染病的监测和预防。

This study aimed to investigate the distribution of tick species and detect the status of pathogen infections in the Yakeshi Section of the forest area in the Greater Khingan Mountains in eastern Inner Mongolia.Free ticks were captured with the flag method during the peak period of tick activity(May to June),and preliminarily morphological classification was performed with a stereomicroscope.The whole genome DNA of ticks was extracted and RT-PCR was used to detect pathogen genes associated with Rickettsia(gltA),Anaplasma(msp2),Ehrlichia(Omp1),Lyme disease miyamotoi(flaB),and Borrelia miyamotoi(glpQ).A total of 2786 ticks were collected and analyzed by stereomicroscopy and gene detection,belonging to 4 species,3 generaone,1 family.Among them,Ixodes persulcatus(78.6%,2191/2786)and Haemaphysalis concinna(15.9%,442/2786)were the dominant ticks in this region.Among the seven sampling areas in yakeshi section of the Greater Khingan Mountains,the positive rate of Rickettsia gltA in Unur was the highest(74.2%,222/299),the positive rate of Anaplasma msp2 in Boketu was the highest(18.9%,39/206),the positive rates of Ehrlichia Omp1,Lyme disease Spirochete flaB and Borrelia miyamotoi glpQ were the highest,accounting for 26.1%(12/46),76.1%(35/46)and 13.0%(6/46),respectively.Except that the comparison of Borrelia miyamotoi was not statistically significant,the detection rates of male ticks were higher than that of female ticks for the other four pathogens(P<0.05).The positivity rates of adult tick Anaplasma msp2,Ehrlichia omp1,and Lyme disease Miyamotoi flaB pathogen were higher than those of nymphs and larvae(P<0.05).The co-infection rate was 19.5%(544/2786)in the Yakeshi Section of the Greater Khingan Mountains.The co-infection rate of two pathogens was 40.6%(186/458)in Minduhe,the co-infection rate of three or more pathogens in Unur was 47.4%(36/76)and 90%(9/10),respectively.The pathogen of Lyme disease miyamotoi had the most severe infection in the Yakeshi Section.The towns of Mianduhe and Wunu'er were the areas with the most severe combined infection.Therefore,monitoring of tick-borne infectious diseases must be strengthened in this area.