Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
Department of Zoonoses, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
BMC Vet Res. 2021 Jan 25;17(1):49. doi: 10.1186/s12917-020-02733-5.
Borrelia burgdorferi is the spirochete that causes Lyme Borreliosis (LB), which is a zoonotic tick-borne disease of humans and domestic animals. Hard ticks are obligate haematophagous ectoparasites that serve as vectors of Borrelia burgdorferi. Studies on the presence of Lyme borreliosis in Egyptian animals and associated ticks are scarce.
This study was conducted to detect B. burgdorferi in different tick vectors and animal hosts. Three hundred animals (dogs=100, cattle=100, and camels=100) were inspected for tick infestation. Blood samples from 160 tick-infested animals and their associated ticks (n=1025) were collected and examined for the infection with B. burgdorferi by polymerase chain reaction (PCR) and sequencing of the 16S rRNA gene. The identified tick species were characterized molecularly by PCR and sequencing of the ITS2 region.
The overall tick infestation rate among examined animals was 78.33% (235/300). The rate of infestation was significantly higher in camels (90%), followed by cattle (76%) and dogs (69%); (P = 0.001). Rhipicephalus sanguineus, Rhipicephalus (Boophilus) annulatus, and both Hyalomma dromedarii and Amblyomma variegatum, were morphologically identified from infested dogs, cattle, and camels; respectively. Molecular characterization of ticks using the ITS2 region confirmed the morphological identification, as well as displayed high similarities of R. sanguineus, H. dromedarii, and A. Variegatu with ticks identified in Egypt and various continents worldwide. Just one dog (1.67%) and its associated tick pool of R. sanguineus were positive for B. burgdorferi infection. The 16S rRNA gene sequence for B. burgdorferi in dog and R. sanguineus tick pool showed a 100% homology.
Analyzed data revealed a relatively low rate of B. burgdorferi infection, but a significantly high prevalence of tick infestation among domesticated animals in Egypt, which possesses a potential animal and public health risk. Additionally, molecular characterization of ticks using the ITS2 region was a reliable tool to discriminate species of ticks and confirmed the morphological identification.
伯氏疏螺旋体是导致莱姆病（LB）的螺旋体，莱姆病是一种人畜共患的节肢动物传播疾病。硬蜱是专性吸血的外寄生虫，是伯氏疏螺旋体的传播媒介。关于埃及动物和相关蜱虫中莱姆病的存在的研究很少。
本研究旨在检测不同蜱虫媒介和动物宿主中的伯氏疏螺旋体。检查了 300 只动物（狗=100，牛=100，骆驼=100）的蜱虫感染情况。从 160 只受感染的动物及其相关蜱虫（n=1025）中采集血液样本，并通过聚合酶链反应（PCR）和 16S rRNA 基因测序检测伯氏疏螺旋体感染。通过 PCR 和 ITS2 区域的测序对鉴定出的蜱种进行分子特征描述。
检查动物的总蜱虫感染率为 78.33%（235/300）。在骆驼（90%）中，感染率显著高于牛（76%）和狗（69%）；（P=0.001）。从受感染的狗、牛和骆驼中形态学鉴定出了红缘蜱、环形牛蜱和边缘革蜱和荒地革蜱。使用 ITS2 区域对蜱进行分子特征描述，不仅证实了形态学鉴定，还显示了红缘蜱、边缘革蜱和荒地革蜱与在埃及和世界各大洲鉴定出的蜱具有高度相似性。只有一只狗（1.67%）及其携带的红缘蜱蜱群对伯氏疏螺旋体感染呈阳性。狗和红缘蜱蜱群中伯氏疏螺旋体的 16S rRNA 基因序列显示出 100%的同源性。
分析数据显示，埃及家养动物中伯氏疏螺旋体感染率相对较低，但蜱虫感染率显著较高，这对动物和公共卫生构成潜在风险。此外，使用 ITS2 区域对蜱进行分子特征描述是区分蜱种的可靠工具，并证实了形态学鉴定。
