Adjou Moumouni Paul Franck, Terkawi Mohamad Alaa, Jirapattharasate Charoonluk, Cao Shinuo, Liu Mingming, Nakao Ryo, Umemiya-Shirafuji Rika, Yokoyama Naoaki, Sugimoto Chihiro, Fujisaki Kozo, Suzuki Hiroshi, Xuan Xuenan
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan; United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan.
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Ticks Tick Borne Dis. 2016 Jul;7(5):828-833. doi: 10.1016/j.ttbdis.2016.03.016. Epub 2016 Apr 9.
Spotted fever group (SFG) rickettsiae are obligate intracellular, Gram-negative bacteria transmitted by ticks and causing febrile illness in humans. Despite the presence of suitable tick vectors, the occurrence of SFG rickettsiae has never been investigated in the Republic of Benin (West Africa). In the present study, 910 Amblyomma variegatum ticks collected from 8 different locations in North Eastern Benin were tested for SFG rickettsiae. The samples were first screened for the presence of rickettsial bacteria using 16S rDNA PCR and positive samples were subsequently characterized by ompA PCR. Randomly selected samples among those positive for both assays were subjected to sequencing of 16S rDNA and ompA genes for species identification. The 16S rDNA gene was amplified in 63.4% of the samples (585/910) and the SFG rickettsia-specific ompA gene was detected in 29.4% of the samples (267/910). The prevalence of SFG rickettsiae varied according to the location, and tick gender. Sequence analyses demonstrated the presence of Rickettsia africae and/or closely related species in Benin. These findings extend the geographic distribution of R. africae and spotted fever rickettsioses in Africa. Clinicians in Benin and those treating travellers should be aware of the possibility of SFG rickettsiae infection when they are treating patients with febrile illness.
斑点热群（SFG）立克次氏体是专性细胞内寄生的革兰氏阴性细菌，通过蜱传播，可导致人类发热性疾病。尽管存在合适的蜱传播媒介，但在贝宁共和国（西非）从未对SFG立克次氏体的发生情况进行过调查。在本研究中，对从贝宁东北部8个不同地点采集的910只变异革蜱进行了SFG立克次氏体检测。首先使用16S rDNA PCR筛选样本中是否存在立克次氏体细菌，随后对阳性样本进行ompA PCR鉴定。在两种检测均呈阳性的样本中随机选择样本，对其16S rDNA和ompA基因进行测序以进行物种鉴定。16S rDNA基因在63.4%的样本（585/910）中扩增成功，SFG立克次氏体特异性ompA基因在29.4%的样本（267/910）中被检测到。SFG立克次氏体的流行率因地点和蜱的性别而异。序列分析表明在贝宁存在非洲立克次氏体和/或密切相关的物种。这些发现扩展了非洲立克次氏体和斑点热立克次体病的地理分布范围。贝宁的临床医生以及治疗旅行者的医生在治疗发热性疾病患者时应意识到感染SFG立克次氏体的可能性。
