Koh Fui Xian, Panchadcharam Chandrawathani, Sitam Frankie Thomas, Tay Sun Tee
Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Department of Veterinary Services, Ministry of Agriculture and Agro-Based Industry Malaysia, Federal Government Administrative Center, Putrajaya, Malaysia; Veterinary Research Institute, 59, Jalan Sultan Azlan Shah, 31400 Ipoh, Perak, Malaysia.
Vet Parasitol Reg Stud Reports. 2018 Aug;13:141-147. doi: 10.1016/j.vprsr.2018.05.006. Epub 2018 Jun 1.
Anaplasma spp. are Gram-negative obligate intracellular, tick-borne bacteria which are of medical and veterinary importance. Little information is available on Anaplasma infection affecting domestic and wildlife animals in Malaysia. This study investigated the presence of Anaplasma spp. in the blood samples of domestic and wildlife animals in Peninsular Malaysia, using polymerase chain reaction (EHR-PCR) assays targeting the 16S rRNA gene of Anaplasmataceae. High detection rates (60.7% and 59.0%, respectively) of Anaplasma DNA were noted in 224 cattle (Bos taurus) and 78 deer (77 Rusa timorensis and one Rusa unicolor) investigated in this study. Of the 60 amplified fragments obtained for sequence analysis, Anaplasma marginale was exclusively detected in cattle while Anaplasma platys/Anaplasma phagocytophilum was predominantly detected in the deer. Based on sequence analyses of the longer fragment of the 16S rRNA gene (approximately 1000 bp), the occurrence of A. marginale, Anaplasma capra and Candidatus Anaplasma camelii in cattle, Candidatus A. camelii in deer and Anaplasma bovis in a goat was identified in this study. To assess whether animals were infected with more than one species of Anaplasma, nested amplification of A. phagocytophilum, A. bovis and Ehrlichia chaffeensis DNA was performed for 33 animal samples initially screened positive for Anaplasmataceae. No amplification of E. chaffeensis DNA was obtained from animals investigated. BLAST analyses of the 16S rDNA sequences from three deer (R. timorensis), a buffalo (Bubalus bubalis) and a cow (B. taurus) reveal similarity with that of Candidatus Anaplasma boleense strain (GenBank accession no.: KX987335). Sequence analyses of the partial gene fragments of major surface protein (msp4) gene from two deer (R. timorensis) and a monitor lizard (Varanus salvator) show the detection of a strain highly similar (99%) to that of A. phagocytophilum strain ZJ-China (EU008082). The findings in this study show the occurrence of various Anaplasma species including those newly reported species in Malaysian domestic and wildlife animals. The role of these animals as reservoirs/maintenance hosts for Anaplasma infection are yet to be determined.
无形体属细菌是革兰氏阴性专性细胞内寄生菌，通过蜱传播，具有医学和兽医学重要性。关于无形体感染对马来西亚家养动物和野生动物的影响，目前所知甚少。本研究利用针对无形体科16S rRNA基因的聚合酶链反应（EHR-PCR）检测方法，调查了马来西亚半岛家养动物和野生动物血液样本中无形体属细菌的存在情况。在本研究中检测的224头牛（Bos taurus）和78只鹿（77只帝汶鹿Rusa timorensis和1只马来水鹿Rusa unicolor）中，无形体DNA的检出率较高（分别为60.7%和59.0%）。在用于序列分析的60个扩增片段中，仅在牛中检测到边缘无形体，而在鹿中主要检测到血小板无形体/嗜吞噬细胞无形体。基于16S rRNA基因较长片段（约1000 bp）的序列分析，本研究确定了牛中边缘无形体、山羊无形体和骆驼无形体候选种的存在，鹿中骆驼无形体候选种的存在以及一只山羊中牛无形体的存在。为评估动物是否感染了不止一种无形体，对最初筛检无形体科呈阳性的33份动物样本进行了嗜吞噬细胞无形体、牛无形体和恰菲埃立克体DNA的巢式扩增。在被调查的动物中未获得恰菲埃立克体DNA的扩增产物。对三只鹿（帝汶鹿）、一头水牛（Bubalus bubalis）和一头奶牛（Bos taurus）的16S rDNA序列进行的BLAST分析显示，其与博莱恩斯无形体候选种菌株（GenBank登录号：KX987335）相似。对两只鹿（帝汶鹿）和一只巨蜥（Varanus salvator）主要表面蛋白（msp4）基因部分基因片段的序列分析显示，检测到一种与嗜吞噬细胞无形体ZJ-China菌株（EU008082）高度相似（99%）的菌株。本研究结果表明，在马来西亚家养动物和野生动物中存在多种无形体物种，包括那些新报道的物种。这些动物作为无形体感染储存宿主/维持宿主的作用尚待确定。
