新疆部分地区羊捻转血矛线虫系统进化与抗药性分析

Analysis on Drug Resistance and Phylogenetic Relationship of Haemonchus contortus in Sheep in Some Areas of Xinjiang

为了解新疆塔城及博乐地区羊捻转血矛线虫的流行情况和系统进化关系,以及这两个地区捻转血矛线虫对苯并咪唑类药物的抗药性,在塔城和博乐地区分别收集20、12个羊皱胃分离捻转血矛线虫,进行形态学鉴定、分子生物学鉴定以及抗药性分析。结果显示:在塔城地区的14个羊皱胃内发现有寄生性线虫,通过PCR鉴定出27只捻转血矛线虫;在博乐地区的7个羊皱胃内发现有寄生性线虫,共鉴定出55只捻转血矛线虫。对PCR阳性样品进行测序并应用最大似然法构建系统发育树进行系统进化分析发现:本试验所测序列与GenBank上的捻转血矛线虫虫株序列聚为一支,置信度为100%;与捻转血矛线虫同科不同属的环纹背带线虫虫株序列相聚类,置信度为100%;其外群为不同科、不同属的羊仰口线虫,登录号为KP792295.1;内群与外群分别形成独立的进化分支。对β-tubulin基因进行多序列比对发现,所选样本并未出现苯并咪唑类药物抗性。本研究有助于了解捻转血矛线虫流行情况,并为捻转血矛线虫系统进化及苯并咪唑类药物抗性分析提供了依据。

In order to make clear the prevalence and phylogenetic relationship of Haemonchus contortus in sheep as well as its resistance to Benzimidazoles in Tacheng and Bole of Xinjiang,20 and 12 sheep abomasa were respectively collected from the two regions to isolate Haemonchus contortus for identification of morphology and molecular biology and drug resistance analysis. The results showed that nematodes were found in 14 and 7 abomasa respectively in Tacheng and Bole,in which,27 and 55 Haemonchus contortus were respectively identified by PCR. Then the positive PCR samples were sequenced,and a phylogenetic analysis was carried out through constructing the phylogenetic tree by use of maximum likelihood method,it was found that,the obtained sequence was grouped together with that of Haemonchus contortus strain published on GenBank,with the confidence level of 100%,and clustered with that of Teladorsagia circumcincta strain that was of the same family but different genus from Haemonchus contortus,with the confidence level of 100%;its outer group was Bunostomum trigonocephalum with GenBank number of KP792295.1,which belonged to different family and genus;the outer group and inner group respectively formed an independent evolutionary branch. No any resistance to Benzimidazoles in the selected samples was detected by multi-sequence comparison of β-tubulin gene. As a conclusion,this study would contribute to recognize the prevalence of Haemonchus contortus and provide the basis for analysis on its evolution and resistance to Benzimidazoles.