Department of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.
Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA; Institute of Bioinformatics, University of Georgia, Athens, GA, 30602, USA.
Vet Parasitol. 2020 Oct;286:109225. doi: 10.1016/j.vetpar.2020.109225. Epub 2020 Sep 5.
The recent identification of isolates of D. immitis with confirmed resistance to the macrocyclic lactone preventatives presents an opportunity for comparative genomic studies using these isolates, and examining the genetic diversity within and between them. We studied the genomes of Wolbachia endosymbionts of five isolates of D. immitis maintained at the University of Georgia. Missouri and Georgia-2 are maintained as drug susceptible isolates, and JYD-27, Yazoo-2013 and Metairie-2014 are resistant to the macrocyclic lactone preventatives. We used whole genome amplification followed by Illumina-based sequencing from 8 to 12 individual microfilariae from each of the five isolates, obtaining a depth of coverage of approximately 40-75 fold for each. The Illumina sequences were used to create new genome assemblies for all the Wolbachia isolates studied. Comparisons of the Wolbachia sequences revealed more than 3000 sequence variations in each isolate. We identified 67 loci specific in resistant isolates but not in susceptible isolates, including 18 genes affected.Phylogenetic analysis suggested that the endosymbionts of the drug-susceptible isolates are more closely related to each other than to those from any of the resistant parasites. This level of variation in the Wolbachia endosymbionts of D. immitis isolates suggests a potential for selection for resistance against drugs targeting them.
最近鉴定出对大环内酯类预防药物有明确抗性的 D. immitis 分离株，为使用这些分离株进行比较基因组研究以及检查它们之间和内部的遗传多样性提供了机会。我们研究了佐治亚大学的五株 D. immitis 沃尔巴克氏体内共生菌的基因组。密苏里州和乔治亚州-2 被维持为药物敏感分离株，而 JYD-27、Yazoo-2013 和 Metairie-2014 对大环内酯类预防药物具有抗性。我们使用全基因组扩增，然后对来自五个分离株中的每个分离株的 8 到 12 个个体微丝蚴进行基于 Illumina 的测序，每个分离株的覆盖率约为 40-75 倍。Illumina 序列用于为所有研究的沃尔巴克氏体分离株创建新的基因组组装。沃尔巴克氏体序列的比较显示，每个分离株中存在 3000 多个序列变异。我们确定了 67 个在耐药分离株中特异性但不在敏感分离株中特异性的基因座，包括 18 个受影响的基因。系统发育分析表明，药物敏感分离株的共生菌彼此之间比任何耐药寄生虫的共生菌更密切相关。这种 D. immitis 分离株沃尔巴克氏体共生菌的变异水平表明对针对它们的药物的抗性有选择潜力。
