Abouelhassan Eman M, GadAllah Sohair, Kamel Marwa S, Kamal Mahmoud, Elsayed Hazem H, Sallam Nahla H, Okely Mohammed
Department of Parasitology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.
Entomology Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt.
Parasitol Res. 2024 Jul 17;123(7):276. doi: 10.1007/s00436-024-08284-0.
The tick Amblyomma lepidum is an ectoparasite of veterinary importance due to its role in transmitting livestock diseases in Africa, including heartwater. This study was conducted in 2023 to monitor Amblyomma spp. infestation in dromedary camels imported from Somalia, Ethiopia, and Sudan to Egypt. This study inspected 200 camels at the Giza governorate's camel market that had been imported from Somalia, 200 from Ethiopia, and 200 from Sudan for tick infestation. Specimens were identified using morphological characteristics and phylogenetic analyses of the 12S and 16S rRNA genes. Clusters were calculated using an unweighted pair-group method with arithmetic averages (UPGMA) dendrogram to group the specimens according to their morphometric characteristics. The morphometric analysis compared the body shape of ticks collected from different countries by analyzing dorsal features. Principal component analysis (PCA) and canonical variate analysis (CVA) were performed to obtain body shape variation among specimens from different countries. Results indicated that camels were infested by 57 males Amblyomma lepidum, and no female specimens were observed; among these specimens, one may have a morphological abnormality. The results suggest that A. lepidum specimens collected from camels imported to Egypt from African countries exhibit locally adapted morphology with variations among specimens, particularly variations in body size. This adaptation suggests minimal potential for genetic divergence. Ecological niche modeling was used to predict the areas in Africa with suitable climates for A. lepidum. The study confirmed that East African countries might have the most favorable climatic conditions for A. lepidum to thrive. Interestingly, the amount of rain during the wettest quarter (Bio16) had the strongest influence on the tick's potential distribution, with suitability decreasing sharply as rainfall increased. Future predictions indicate that the climatic habitat suitability for A. lepidum will decrease under changing climate conditions. However, historical, current, and future predictions indicate no suitable climatic habitats for A. lepidum in Egypt. These findings demand continuous surveillance of A. lepidum in camel populations and the development of targeted strategies to manage tick infestations and prevent the spread of heartwater disease.
蜱虫莱氏钝缘蜱是一种具有兽医重要性的外寄生虫，因为它在非洲传播包括心水病在内的家畜疾病方面发挥着作用。本研究于2023年开展，旨在监测从索马里、埃塞俄比亚和苏丹进口到埃及的单峰骆驼身上的钝缘蜱属蜱虫感染情况。本研究在吉萨省的骆驼市场检查了200头从索马里进口的骆驼、200头从埃塞俄比亚进口的骆驼和200头从苏丹进口的骆驼是否有蜱虫感染。利用形态特征以及12S和16S rRNA基因的系统发育分析对标本进行鉴定。使用算术平均法的非加权配对组法（UPGMA）树形图计算聚类，以便根据形态测量特征对标本进行分组。形态测量分析通过分析背部特征比较了从不同国家采集的蜱虫的体型。进行主成分分析（PCA）和典型变量分析（CVA）以获得来自不同国家的标本之间的体型差异。结果表明，骆驼身上有57只雄性莱氏钝缘蜱，未观察到雌性标本；在这些标本中，有一只可能存在形态异常。结果表明，从非洲国家进口到埃及的骆驼身上采集的莱氏钝缘蜱标本呈现出局部适应的形态，标本之间存在差异，尤其是体型差异。这种适应性表明遗传分化潜力最小。生态位建模用于预测非洲适合莱氏钝缘蜱生存的气候区域。该研究证实，东非国家可能拥有莱氏钝缘蜱繁衍的最有利气候条件。有趣的是，最湿润季度的降雨量（Bio16）对蜱虫的潜在分布影响最大，随着降雨量增加，适宜性急剧下降。未来预测表明，在气候变化条件下，莱氏钝缘蜱的气候栖息地适宜性将降低。然而，历史、当前和未来预测均表明埃及没有适合莱氏钝缘蜱生存的气候栖息地。这些发现需要持续监测骆驼种群中的莱氏钝缘蜱，并制定针对性策略来管理蜱虫感染和预防心水病的传播。
