黑龙江省部分地区牛无形体感染的分子流行病学调查

Molecular epidemiological investigation of Anaplasma species from cattle in some areas of Heilongjiang province

为了解黑龙江省蜱传牛无形体的感染情况,本研究于2019年采集黑龙江省大兴安岭、哈尔滨、齐齐哈尔、牡丹江和黑河5个地区共174份牛的全血样品。通过PCR扩增无形体16S rRNA基因,将获得的所有PCR产物均测序后经Blast分析,并与GenBank中已登录的不同种属无形体相应基因比对,分析其同源性,统计不同地区无形体及其不同种属的感染率。选择同源性最高的16S rRNA基因构建进化树进一步分析感染无形体的种属。PCR结果显示,40份全血样品出现350 bp的目的条带,26份全血样品出现270 bp的目的条带。测序后经Blast比对结果显示,所测这两种基因序列均与无形体相应基因序列的同源性最高,表明上述66份全血样品均为无形体感染。统计结果显示,黑龙江省牛无形体的总感染率为37.93%(66/174),其中大兴安岭、哈尔滨、齐齐哈尔、牡丹江、黑河的阳性率分别为52.38%(22/42)、33.33%(9/27)、22.45%(11/49)、40.63%(13/32)、45.83%(11/24);无形体不同种属16S rRNA基因的同源性分析结果显示,66份牛全血样品中共有3种无形体:嗜吞噬细胞无形体、边缘无形体和牛无形体,阳性率分别为12.12%(8/66)、 60.60%(40/66)和27.27%(18/66)。基于无形体16S rRNA基因构建的系统进化树结果与同源性分析结果一致,即感染的无形体有上述3种。以上结果表明,黑龙江省5个地区的牛均有无形体的感染,且感染的无形体为上述3种,提示蜱传无形体在黑龙江省牛群中的普遍存在。本研究为黑龙江省蜱传无形体病的防控提供科学依据,并更新了黑龙江省家畜蜱传无形体病的数据。

To investigate Anaplasma infection of cattle in Heilongjiang province, we collected 174 blood samples of cattle from five regions: Daxing’anling, Harbin, Qiqihar, Mudanjiang, and Heihe in 2019. The 16 S rRNA genes of Anaplasma were amplified, and the PCR products were sequenced, blasted with the sequences obtained from GenBank. The infection rates of Anaplasma from different regions and species were counted. Subsequently, a phylogenetic tree was constructed based on the sequences with the highest homology for further analysis of the Anaplasma infection. The PCR product size from 40 whole blood samples was 350 bp, while the PCR product from 26 whole blood samples showed a 270 bp size. The PCR products were sequenced and blasted online based on 16 S rRNA gene. The result showed that the sequences have the highest homology with the Anaplasma.The total Anaplasma infection rate of cattle in Heilongjiang province was 37.93%(66/174). The positive rate was 52.38%(22/42)in Daxing’anling, followed by 45.83%(11/24) in Heihe, 40.63%(13/32) in Mudanjiang, 33.33%(9/27) in Harbin, 22.45%(11/49)in Qiqihar. There are three Anaplasma species(Anaplasma phagocytophilum, Anaplasma marginale and Anaplasma bovis) in cattle blood according to the phylogenetic tree based on 16 s r RNA gene from Anaplasma. A total of 66 positive samples and the positive rate was 12.12%(8/66), 60.60%(40/66) and 27.27%(18/66), respectively. The results showed that all five regions of Heilongjiang province had Anaplasma infection, suggesting a prevalence of tick-borne Anaplasma in Heilongjiang province. This study provided a scientific basis for preventing and controlling tick-borne Anaplasma disease in Heilongjiang province and updated the data of tickborne Anaplasmosis in Heilongjiang province.