Microsatellite marker analysis of Haemonchus contortus populations from Pakistan suggests that frequent benzimidazole drug treatment does not result in a reduction of overall genetic diversity.
Microsatellite marker analysis of Haemonchus contortus populations from Pakistan suggests that frequent benzimidazole drug treatment does not result in a reduction of overall genetic diversity.
复制标题
DOI：
10.1186/s13071-016-1624-0
复制
发表时间：
2016-06-17
影响因子：
3.2
通讯作者：
Gilleard JS
中科院分区：
文献类型：
--
作者：
Chaudhry U;Redman EM;Ashraf K;Shabbir MZ;Rashid MI;Ashraf S;Gilleard JS
药物选择压力对该领域寄生线虫种群整体遗传多样性的影响知之甚少。在这项研究中，我们解决这个问题的小反刍动物寄生虫捻转血矛线虫在巴基斯坦的旁遮普。该区域提供了比较H.在政府农场中长期频繁接受苯并咪唑药物治疗的捻转虫种群与在邻近牧群中很少或没有接受药物治疗的寄生虫种群之间的比例。成年H.从三个经常使用苯并咪唑药物的政府农场的小型反刍动物的皱胃中收集捻转蠕虫，并且关闭动物运动，超过30年，还从18个进行最小药物选择的牧群中收集捻转虫。在每个寄生虫种群中测定三种已知苯并咪唑耐药相关突变的频率。对发现耐药突变的7个寄生虫种群进行了1 β-微管蛋白苯并咪唑耐药单倍型的多样性、地理分布和系统发育关系分析。此外，寄生虫种群的遗传多样性的三个政府农场进行了比较，从四个牧区。F200 Y（TAC）耐药突变在H.来自政府畜群的捻转牛种群，但不是来自牧区畜群，这与它们各自的药物选择历史一致。群体遗传分析，使用一个面板的微卫星标记，发现寄生虫种群之间的遗传分化很小，政府和牧区畜群之间的整体遗传多样性没有显着差异。此外，同种型-1 β-微管蛋白基因座的序列分析揭示了多个F200 Y（TAC）单倍型，即使在几乎没有或没有当代寄生虫迁移的政府畜群中也表现出软选择性扫描。结果表明，虽然政府农场频繁使用的药物治疗选择了苯并咪唑耐药突变的频率很高，但所选寄生虫种群的总体遗传多样性很少或没有减少。本文的在线版本（doi：10.1186/s13071-016-1624-0）包含补充材料，可供授权用户使用。
The impact of drug selection pressure on the overall genetic diversity of parasitic nematode populations in the field is poorly understood. In this study, we address this issue for the small ruminant parasite Haemonchus contortus in the Punjab, Pakistan. This region provides an opportunity to compare H. contortus populations that have been subjected to a prolonged period of frequent benzimidazole drug treatments on government farms with parasite populations that have been exposed to little or no drug treatment in neighbouring pastoral herds. Adult H. contortus worms were collected from the abomasa of small ruminants from three government farms frequently using benzimidazole drugs, and closed to animal movement, for over 30 years and also from from eighteen pastoral herds subject to minimal drug selection. The frequency of three known benzimidazole resistance associated mutations was determined in each parasite population. For the seven parasite populations in which resistance mutations were found, the diversity, geographical distribution and phylogenetic relationships of isotype-1 β-tubulin benzimidazole resistance haplotypes were determined. In addition, the genetic diversity of the parasite populations on the three government farms were compared with those from four pastoral herds. The F200Y (TAC) resistance mutation was present at a very high frequency in H. contortus populations from government herds, but not from pastoral herds, consistent with their respective drug selection histories. Population genetic analysis, using a panel of microsatellite markers, revealed that there was little genetic differentiation among the parasite populations with no significant difference in the overall genetic diversity between government and pastoral herds. In addition, sequence analysis of the isotype-1 β-tubulin locus revealed multiple F200Y (TAC) haplotypes demonstrating soft selective sweeps even in government herds with little or no contemporary parasite migration. The results suggest that, although the frequent drug treatment used on government farms has selected for a high frequency of benzimidazole resistance mutations, there has been little or no reduction in the overall genetic diversity of the selected parasite populations. The online version of this article (doi:10.1186/s13071-016-1624-0) contains supplementary material, which is available to authorized users.