云南省梁河县鼠疫疫源地野外鼠形动物嗜吞噬细胞无形体感染调查

Investigation of Anaplasma phagocytophilum infection in wild small mammals in the plague foci of Lianghe County, Yunnan Province

目的了解云南省梁河县鼠疫疫源地野外鼠形动物嗜吞噬细胞无形体自然感染情况。方法应用单纯随机抽样法,从665份野外鼠形动物肝脾标本中抽取407份,采用巢式PCR对样本进行嗜吞噬细胞无形体16SrRNA基因检测,并对扩增产物测序,应用生物软件MEGA7.0将所测序列与GenBank注册的其它无形体属种株进行序列对比分析。结果检测野外鼠形动物3目5科12属17种407只,阳性率为3.19%(13/407),其中大足鼠、黄胸鼠和斯氏家鼠阳性率分别为21.43%(3/14)、6.00%(6/100)和4.94%(4/81),其它鼠形动物均未检测出阳性;不同海拔梯度(P=0.219)、不同性别(χ^2=0.441,P=0.506)及不同生境间(χ^2=0.386,P=0.534)鼠形动物嗜吞噬细胞无形体感染率差异无统计学意义;不同季节野外鼠形动物嗜吞噬细胞无形体感染率差异具有统计学意义(P=0.044);序列对比分析显示所有样本基因序列与GenBank中收录的国内外部分嗜吞噬细胞无形体16SrRNA基因序列同源性达100%,进化分析显示与国内外部分嗜吞噬细胞无形体处同一个分支。结论云南省梁河县鼠疫疫源地野外鼠形动物存在嗜吞噬细胞无形体低度感染。

To investigate Anaplasma phagocytophilum infection of wild small mammals in the plague foci of Lianghe county,Yunnan Province,four hundred and seven liver and spleen were selected from 665 wild small mammals by simple random sampling method.Nest-PCR was used to detect the 16S rRNA gene of Anaplasma phagocytophilum.The positive PCR products were sequenced and compared by biological software MEGA7.0 with the corresponding parts of the 16S rRNA sequence in GenBank.A total of 407 wild small mammals,belonging to 17species,12 genus,5 families,and 3 orders,were detected.The results showed that the positive rate was 3.19%(13/407).The infection rate of R.nitidus,Rattus tanezumi and R.brunneusculus was 21.43%(3/14),6.00%(6/100)and 4.94%(4/81),respectively.None of the other wild small mammals was positive.There were no statistical significance for the infection rates of small mammals between different elevation gradients(P=0.2188),gender(χ^2=0.441,P=0.506)and habitat(χ^2=0.386,P=0.534),but statistical significance among different seasons(P=0.044)were dound.Results by sequence analysis indicated that the similarities of the nucleotide sequences with parts of the Anaplasma phagocytophilum sequence in GenBank were 100%,and the strains in this study were located in the same clade as Anaplasma phagocytophilum in the phylogenetic tree.In conclusion,there is a low infection rate of Anaplasma phagocytophilum from wild small mammals in Lianghe county plague foci,Yunnan Province.