Infectious Diseases Department, Center of Rickettsiosis and Arthropod-Borne Diseases (CRETAV), San Pedro University Hospital-Center of Biomedical Research From La Rioja (CIBIR), Piqueras, 98, 26006, Logroño, La Rioja, Spain.
Infectious Diseases Department, Vall d'Hebron University Hospital, PROSICS Barcelona, 08035, Barcelona, Spain.
Parasit Vectors. 2022 Apr 21;15(1):140. doi: 10.1186/s13071-022-05238-2.
Ticks and tick-borne diseases constitute a real threat for the livestock industry, which is increasing in Angola. In addition, ticks are vectors of zoonoses of public health concern, and scarce information is available from this country. In an effort to contribute to the prevention of zoonotic infectious diseases affecting humans and animals, the molecular screening of certain tick-related microorganisms collected on cattle in Angola was performed under a 'One Health' scope.
Ticks collected from cattle in Cubal (Benguela Province, Angola) in July 2017 were analysed in pools using specific PCR assays for bacteria (Rickettsia, Anaplasmataceae, Borrelia, Coxiella and Spiroplasma) and protozoa (Theileria and Babesia) detection.
A total of 124 tick specimens were grouped in 25 pools (two Amblyomma variegatum, three Hyalomma truncatum, 16 Rhipicephalus decoloratus, two Rhipicephalus duttoni, one Rhipicephalus evertsi mimeticus and one Rhipicephalus sp.). The amplified microorganisms were (pools): Rickettsia africae (two A. variegatum and one R. decoloratus), Rickettsia aeschlimannii (three H. truncatum), Ehrlichia spp. (six R. decoloratus), Coxiella spp. (all but H. truncatum), Francisella sp. (one H. truncatum), Spiroplasma sp. closely related to Spiroplasma ixodetis (three R. decoloratus), Babesia bigemina (two R. decoloratus) and Babesia spp. (two A. variegatum). The obtained nucleotide sequences from Ehrlichia spp., two Coxiella genotypes (from R. duttoni and Rhipicephalus sp.), Francisella sp. and Babesia spp. (from A. variegatum) reached low identities with known genetically characterized species.
This study demonstrates the circulation in Angola of the pathogen R. aeschlimannii and potential novel tick-related microorganisms belonging to Ehrlichia, Coxiella, Francisella, Spiroplasma and Babesia spp. and corroborates the presence of R. africae and B. bigemina. Our results should be considered in developing protocols for the management of fever of unknown origin and for veterinary practices. Further studies are required to evaluate the risk of tick-borne diseases in Angola.
蜱虫和蜱传疾病对安哥拉不断发展的畜牧业构成了真正的威胁。此外，蜱虫是公共卫生关注的人畜共患传染病的媒介，而该国的相关信息却十分匮乏。为了帮助预防影响人类和动物的人畜共患传染病，我们在“同一健康”的范围内对安哥拉牛身上采集的某些与蜱虫相关的微生物进行了分子筛查。
2017 年 7 月在安哥拉库巴尔（本格拉省）收集的牛蜱虫被分组为 25 个池进行分析，使用特定的 PCR 检测方法检测细菌（立克次体、无形体科、巴尔通体、考克斯体和螺旋体）和原生动物（泰勒虫和巴贝斯虫）。
共分析了 124 个蜱虫样本，分为 25 个池（两个变异性孤雌蜱、三个钝缘蜱、16 个无色革蜱、两个德氏血蜱、一个拟革蜱和一个未知蜱）。扩增的微生物为（池）：非洲立克次体（两个变异性孤雌蜱和一个无色革蜱）、非洲埃立克体（三个钝缘蜱）、埃希利希体属（六个无色革蜱）、考克斯体属（除钝缘蜱外）、弗朗西斯菌属（一个钝缘蜱）、与螺旋体 ixodetis 密切相关的螺旋体属（三个无色革蜱）、双芽巴贝斯虫（两个无色革蜱）和巴贝斯虫属（两个变异性孤雌蜱）。从埃希利希体属、两个考克斯体基因型（来自德氏血蜱和未知蜱）、弗朗西斯菌属和巴贝斯虫属（来自变异性孤雌蜱）获得的核苷酸序列与已知基因特征的种属具有较低的同一性。
本研究表明，病原体非洲立克次体和潜在的新型与蜱虫相关的微生物，如埃希利希体属、考克斯体属、弗朗西斯菌属、螺旋体属和巴贝斯虫属，在安哥拉循环。此外，本研究还证实了非洲牛蜱和双芽巴贝斯虫的存在。我们的研究结果应在制定不明原因发热的管理和兽医实践协议中加以考虑。需要进一步研究以评估安哥拉蜱传疾病的风险。
