Department of Dermatology, Bundeswehr Hospital Hamburg, Lesserstr. 180, 22049 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
Ticks Tick Borne Dis. 2018 May;9(4):1049-1056. doi: 10.1016/j.ttbdis.2018.03.022. Epub 2018 Mar 29.
In western and eastern Africa, rickettsioses are one cause of fever in humans. Little is known regarding the presence of Rickettsia sp. in northern Cameroon. The present work was conducted in order to identify potential tick-borne spotted fever group Rickettsia in the Adamawa region of northern Cameroon, which may contribute filling some of the knowledge gaps of these pathogens. Ticks were collected from cattle in the municipal slaughterhouse of Ngaoundere in the Adamawa region of northern Cameroon. After morphological identification of tick species, extracted DNA was analyzed by PCR targeting the rickettsial ompB gene and the intergenic spacers dksA-xerC, mppA-purC and rpmE-tRNA Of the 316 adult ticks collected, 149 (47.1%) were Amblyomma variegatum, 92 (29%) Rhipicephalus spp. and 75 (23.7%) Hyalomma spp. Through the use of conventional PCR assays for the rickettsial ompB gene, rickettsial DNA was detected in 104 (32.9%) samples (85 Amblyomma sp., 14 Hyalomma spp. and 5 Rhipicephalus spp.). The ompB gene and the three intergenic were sequenced for 10 ticks in order to determine the rickettsial species. Rickettsia africae was detected in Amblyomma variegatum, Rickettsia aeschlimannii in Hyalomma rufipes and Hyalomma truncatum, Rickettsia sibirica in H. truncatum, Rickettsia massiliae in Rhipicephalus lunulatus and Candidatus Rickettsia barbariae in R. lunulatus. To the best of the author's knowledge, this report represents the first molecular evidence of rickettsial infection in ticks in the Adamawa region of northern Cameroon, which suggests a possible exposure of the human population in this region.
在西非和东非，立克次体病是人类发热的一个原因。关于喀麦隆北部的里氏立克次体属在北部喀麦隆阿达马瓦地区的存在，人们知之甚少。本研究旨在确定可能存在于喀麦隆北部阿达马瓦地区的蜱传斑点热群立克次体，这可能有助于填补这些病原体的一些知识空白。在喀麦隆北部阿达马瓦地区的恩冈代雷市屠宰场收集了来自牛的蜱。在对蜱种进行形态学鉴定后，提取的 DNA 通过针对立克次体 ompB 基因和基因间间隔 dksA-xerC、mppA-purC 和 rpmE-tRNA 的 PCR 进行分析。在收集的 316 只成蜱中，149 只为变色革蜱（Amblyomma variegatum）（47.1%），92 只为钝缘蜱属（Rhipicephalus spp.）（29%），75 只为璃眼蜱属（Hyalomma spp.）（23.7%）。通过使用常规 PCR 检测立克次体 ompB 基因，在 104 个样本（85 只变色革蜱、14 只璃眼蜱属和 5 只钝缘蜱属）中检测到立克次体 DNA。为了确定立克次体的种类，对 10 只蜱进行了 ompB 基因和 3 个基因间区的测序。在变色革蜱中检测到非洲立克次体，在红缘璃眼蜱和三形璃眼蜱中检测到阿氏立克次体，在三形璃眼蜱中检测到西伯利亚立克次体，在卢氏钝缘蜱中检测到马赛立克次体，在卢氏钝缘蜱中检测到巴尔通体。据作者所知，这是首次在喀麦隆北部阿达马瓦地区的蜱中报告立克次体感染的分子证据，这表明该地区的人类可能有感染风险。
