PCR Detection and Serological Evidence of Granulocytic Ehrlichial Infection in Roe Deer (Capreolus capreolus) and Chamois (Rupicapra rupicapra)

The role of wild mammals, such as roe deer (Capreolus capreolus) and chamois (Rupicapra rupicapra), in the epidemiology of granulocytic ehrlichiae in Switzerland was investigated. We tested blood samples for Ehrlichia phagocytophila genogroup 16S rRNA gene sequences by PCR and for immunoglobulin G antibodies against granulocytic ehrlichiae by indirect fluorescent-antibody assay (IFA). Overall means of 60.9% of 133 roe deer serum samples and 28.2% of 39 chamois serum samples were seroreactive by IFA. PCR results were positive for 18.4% of 103 roe deer serum samples as well. None of the 24 chamois blood samples tested were positive by PCR. Partial 16S rRNA gene and groESL heat shock operon sequences of three roe deer samples tested showed strong degrees of homology (≥99.7 and ≥98.6%, respectively) with the sequences of granulocytic ehrlichiae isolated from humans. These results confirm that chamois, and particularly roe deer, are commonly infected with granulocytic ehrlichiae and provide evidence that these wild mammals are potential reservoirs for granulocytic ehrlichiae in Switzerland.

本研究针对瑞士粒细胞埃立克体（granulocytic ehrlichiae）的流行病学传播，探究了狍（roe deer，Capreolus capreolus）与岩羚羊（chamois，Rupicapra rupicapra）等野生哺乳动物所扮演的角色。研究人员通过聚合酶链式反应（Polymerase Chain Reaction，PCR）检测了血液样本中的嗜吞噬细胞埃立克体群（Ehrlichia phagocytophila genogroup）16S核糖体RNA基因（16S rRNA gene）序列，并通过间接免疫荧光试验（indirect fluorescent-antibody assay，IFA）检测了针对粒细胞埃立克体的免疫球蛋白G（immunoglobulin G，IgG）抗体。结果显示，133份狍血清样本中有60.9%、39份岩羚羊血清样本中有28.2%经IFA检测呈现血清学阳性反应；103份狍血清样本的PCR检测结果亦有18.4%呈阳性，而24份岩羚羊血液样本的PCR检测结果均为阴性。对3份狍样本的部分16S rRNA基因与groESL热休克操纵子（groESL heat shock operon）序列进行分析后发现，其与从人类体内分离得到的粒细胞埃立克体序列同源性分别≥99.7%与≥98.6%。上述结果证实，岩羚羊尤其是狍普遍感染粒细胞埃立克体，为这类野生哺乳动物是瑞士粒细胞埃立克体的潜在储存宿主提供了实验依据。