2019-2020云南省部分地区啮齿动物感染无形体的多样性

Diversity of Anaplasma in rodents in some areas of Yunnan province,China,2019-2020

目的了解云南省小型兽类感染无形体的情况,为当地无形体病的防控提供科学依据。方法2019—2020年在云南省西部2个县(市),北部5个县(市)选点,采用笼日法和夹夜法捕获小型兽类,经形态鉴定后取肝、脾脏器组织,提取DNA,用半巢式聚合酶链式反应(PCR)扩增无形体属16S rRNA基因660 bp目的片段,对阳性产物进行测序,所得序列作同源性分析和遗传进化分析。结果共捕获小型兽类1142只,经鉴定分属3目8科21属39种。PCR扩增阳性21份,总阳性率1.84%。其中14份为嗜吞噬细胞无形体,6份为绵羊无形体,1份为牛无形体。阳性小型兽类分属1目2科3属6种,均是啮齿动物。在孟连县和元谋县的斯氏家鼠、黄胸鼠、褐家鼠中检出嗜吞噬细胞无形体;在元谋县的斯氏家鼠、黄胸鼠、社鼠和大绒鼠中检出绵羊无形体;在孟连县的白腹鼠中检出牛无形体。统计学分析表明,孟连县和元谋县的小型兽类无形体感染率差异有统计学意义(P<0.01);不同阳性鼠种的感染率差异有统计学意义(P<0.01),白腹鼠和斯氏家鼠感染率较高;不同性别、年龄、生境和海拔的啮齿目小型兽类感染率差异无统计学意义。结论云南省啮齿动物携带多种可导致人群和家畜致病的无形体,宿主种类多,但地域分布相对集中,应当重点关注人群、家畜的无形体病的预防控制。

Objective To investigate the infection status of Anaplasma spp.in small mammals in Yunnan province,and provide scientific basis for the prevention and control of anaplasmosis.Methods From 2019 to 2020,small mammals were captured by snap traps and rat cages in 2 counties in the west of Yunnan and 5 counties in the north of Yunnan.After morphological identification,DNA was extracted from liver and spleen tissues of small mammals,and then the 660 bp target fragment of 16S rRNA gene of Anaplasma was amplified by semi-nested PCR.The positive amplicons was sequenced,and the recovered sequence was analyzed for homology and genetic evolution.Results A total of 1142 small mammals belonging to39 species,21 genera,8 families,3 orders were collected,and 21 samples from the small mammals were positive by PCR(1.84%).Among of the small mammals,14 were infected with A.phagocytophilum,6 were infected with A.ovis and 1 was infected with A.bovis.The positive small mammals belonging to 6 species,3 genera,2 families,1 order and all were rodents.A.phagocytophilum was detected in R.brunneusculus,R.tanezumi and R.norvegicus in Menglian and Yuanmou counties.A.ovis were detected in R.brunneusculus,R.tanezumi,N.confucianus and E.miletus in Yuanmou county.A.bovis was detected in N.coxingi in Menglian county.Statistical analysis showed that there was a statistical difference in detection rate of Anaplasma in small mammals between Menglian county and Yuanmou county,and there was a statistical difference in detection rate of Anaplasma among small mammals,the detection rate was higher in N.coxingi and R.brunneusculus.No gender,age,habitat and altitude specific differences in detection rate of Anaplasma small mammals of Rodentia were observed.Conclusion Many kinds of rodents in Yunnan carry a variety of anaplasmosis pathogens that can cause disease in human and domestic animals.The various hosts are mainly distributed in some areas,where the prevention and control of anaplasmosis in local people and livestock should be strengthened.