Ben Said Mourad, Selmi Rachid, Rhouma Mohamed Hamza, Belkahia Hanène, Messadi Lilia
Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, 2020 Sidi Thabet, Tunisia.
Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, 2020 Sidi Thabet, Tunisia.
Ticks Tick Borne Dis. 2020 Sep;11(5):101447. doi: 10.1016/j.ttbdis.2020.101447. Epub 2020 Apr 30.
Anaplasma ovis, the causative agent of ovine anaplasmosis in tropical and subtropical countries, is a tick-borne obligatory intraerythrocytic bacterium of sheep, goats and wild ruminants. In Tunisia, data about the molecular phylogeny and the genetic diversity of A. ovis isolates are limited to the analysis of msp4 and groEL genes. The aim of this study was to genetic characterize 40 A. ovis isolates infecting 28 goats, 10 sheep, one camel and one Rhipicephalus turanicus tick located in different geographic regions of Tunisia on the basis of 3 partial genes (gltA, groEL and msp1a). Sequence analysis revealed 6 and 17 different genotypes in the partial gltA and groEL genes, respectively. Phylogenetic analysis revealed, as expected for the groEL gene, that sequences from small ruminants and their infesting ticks clustered separately from those isolated from camels. The analysis of amino-acid Msp1a sequences identified 18 novel genotypes of Msp1a repeats from 20 A. ovis isolates. These Msp1a repeats were highly variable with 33-47 amino-acids, and the number of repeats is one for 19 isolates infecting 18 goats and one R. turanicus tick, and 4 for a single isolate found in one sheep. Phylogenetic trees based on Msp1a partial sequences revealed that the N-terminal region of Msp1a protein appear to be relatively more informative phylogeographically compared to other markers especially according to countries. The presented data give a more detailed knowledge regarding the molecular phylogeny and the genetic diversity of A. ovis isolates occurring in different animal species and their associated ticks in Tunisia.
绵羊无形体是热带和亚热带国家绵羊无形体病的病原体，是一种由蜱传播的、寄生于绵羊、山羊和野生反刍动物红细胞内的专性细菌。在突尼斯，关于绵羊无形体分离株的分子系统发育和遗传多样性的数据仅限于对msp4和groEL基因的分析。本研究的目的是基于3个部分基因（gltA、groEL和msp1a）对来自突尼斯不同地理区域的40株感染28只山羊、10只绵羊、1峰骆驼和1只图兰扇头蜱的绵羊无形体分离株进行遗传特征分析。序列分析显示，部分gltA基因和groEL基因分别有6种和17种不同的基因型。系统发育分析表明，正如groEL基因所预期的那样，小反刍动物及其寄生蜱的序列与从骆驼分离出的序列分别聚类。对氨基酸Msp1a序列的分析从20株绵羊无形体分离株中鉴定出18种新的Msp1a重复基因型。这些Msp1a重复序列高度可变，有33 - 47个氨基酸，19株感染18只山羊和1只图兰扇头蜱的分离株的重复序列数为1，而在1只绵羊中发现的单个分离株的重复序列数为4。基于Msp1a部分序列的系统发育树显示，与其他标记相比，Msp1a蛋白的N端区域在系统地理学上似乎更具信息性，尤其是根据国家来看。所呈现的数据提供了关于突尼斯不同动物物种及其相关蜱中出现的绵羊无形体分离株的分子系统发育和遗传多样性的更详细信息。
