PDF(Pubmed)
Abstract：
The recent emergence of anaplasmosis in camels has raised global interest in the pathogenicity and zoonotic potential of the pathogen causing it and the role of camels as reservoir hosts. In the United Arab Emirates (UAE), molecular studies and genetic characterization of camel-associated Anaplasma species are limited. This study aimed to characterize molecularly Anaplasmataceae strains circulating in dromedary camels in the UAE. Two hundred eighty-seven whole-blood samples collected from dromedary camels across regions of the Abu Dhabi Emirate were received between 2019 and 2023 at the Abu Dhabi Agriculture and Food Safety Authority (ADAFSA) veterinary laboratories for routine diagnosis of anaplasmosis. The animals were sampled based on field clinical observation by veterinarians and their tentative suspicion of blood parasite infection on the basis of similar clinical symptoms as those caused by blood parasites in ruminants. The samples were screened for Anaplasmataceae by PCR assay targeting the groEL gene. Anaplasmataceae strains were further characterized by sequencing and phylogenetic analysis of the groEL gene. Thirty-five samples (35/287 = 12.2%) tested positive for Anaplasmataceae spp. by PCR assay. Nine positive samples (9/35 = 25.7%) were sequenced using groEL gene primers. GenBank BLAST analysis revealed that all strains were 100% identical to the Candidatus A. camelii reference sequence available in the GenBank nucleotide database. Phylogenetic analysis further indicated that the sequences were close to each other and were located in one cluster with Candidatus A. camelii sequences detected in Saudi Arabia, Morocco, and the UAE. Pairwise alignment showed that the UAE sequences detected in this study were completely identical and shared 100% identity with Candidatus A. camelii from Morocco and Saudi Arabia and 99.5% identity with Candidatus A. camelii from the UAE. This study demonstrates the presence of Candidatus A. camelii in UAE dromedary camels. Further critical investigation of the clinical and economical significance of this pathogen in camels needs to be carried out.
摘要：
最近在骆驼中出现的无形体病引起了全球对病原体的致病性和人畜共患潜力以及骆驼作为水库宿主的作用的兴趣。在阿拉伯联合酋长国（阿联酋），分子研究和遗传特征的骆驼相关的无性体物种是有限的。这项研究旨在表征在阿联酋单峰骆驼中循环的分子无性体科菌株。2019年至2023年期间，阿布扎比农业和食品安全局（ADAFSA）兽医实验室收到了从阿布扎比酋长国单峰骆驼收集的二百八十七份全血样本，用于常规诊断无菌病。根据兽医的现场临床观察以及他们对血液寄生虫感染的初步怀疑，根据与反刍动物中血液寄生虫引起的临床症状相似的临床症状，对动物进行采样。通过靶向groEL基因的PCR分析筛选样品的无性子科。通过对groEL基因进行测序和系统发育分析，进一步鉴定了无性子科菌株。35个样品（35/287=12.2％）的比活菌科属物种呈阳性。通过PCR检测。使用groEL基因引物对9个阳性样品(9/35=25.7%)进行测序。GenBankBLAST分析揭示所有菌株与GenBank核苷酸数据库中可用的CandidatusA.camelii参考序列100%相同。系统发育分析进一步表明，这些序列彼此接近，并且位于沙特阿拉伯检测到的CandidatusA.camelii序列中的一个簇，摩洛哥,和阿联酋。配对比对显示，本研究中检测到的UAE序列完全相同，与摩洛哥和沙特阿拉伯的CandidatusA.camelii具有100％的同一性，与阿联酋的CandidatusA.camelii具有99.5％的同一性。这项研究证明了阿联酋单峰骆驼中存在CandidatusA.camelii。需要对这种病原体在骆驼中的临床和经济意义进行进一步的关键研究。
