State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu 730046, PR China; Qinghai Provincial Center for Animal Disease Control and Prevention, Xining, 810003, Qinghai, PR China.
State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Xujiaping 1, Lanzhou, Gansu 730046, PR China.
Infect Genet Evol. 2018 Jan;57:1-7. doi: 10.1016/j.meegid.2017.10.025. Epub 2017 Oct 28.
Tick-borne rickettsioses is one of the oldest known vector-borne diseases and has been viewed as emerging or re-emerging disease in China. The causative agents have been increasingly recognized and exhibited a high degree of genetic diversity and widespread distribution. This study was conducted to determine the prevalence of spotted fever group rickettsiae in ticks from Qinghai Province, northwestern China. In total, 860 questing adult ticks representing six species were collected. The SFG rickettsiae were detected in Haemaphysalis qinghaiensis (19.6%, 79/404), Dermacentor abaensis (73.7%, 157/213), Dermacentor silvarum (50.0%, 47/94), Dermacentor nuttalli (67.4%, 97/144), and Ixodes crenulatus (100%, 3/3), with an overall infection rate of 44.5%. The infection rates of SFG rickettsiae were significantly higher in Dermacentor spp. than in Haemaphysalis spp. (p<0.05). Sequence analyses of the gltA and ompA genes revealed that five SFG rickettsiae are present in ticks in Qinghai, including R. sibirica subspecies sibirica, R. raoultii, "Candidatus Rickettsia tibetani", and "Candidatus Rickettsia gannanii" Y27 and F107. Moreover, a potential novel Rickettsia species (Rickettsia sp. 10CYF) was identified in D. nuttalli and I. crenulatus. These findings extend our knowledge of the potential vector spectrum and distribution of rickettsiae, and provided valuable information for assessing the potential risk for public health.
蜱传斑疹热群立克次体病是已知最古老的虫媒传染病之一，在中国被视为新发或再发传染病。其病原体的认识不断增加，并表现出高度的遗传多样性和广泛的分布。本研究旨在确定中国西北部青海省蜱中斑点热群立克次体的流行情况。共采集了代表六个种的 860 只成年游离蜱。在青海血蜱（19.6%，79/404）、阿坝硬蜱（73.7%，157/213）、草原革蜱（50.0%，47/94）、努氏钝缘蜱（67.4%，97/144）和三棘血蜱（100%，3/3）中检测到 SFG 立克次体，总感染率为 44.5%。在硬蜱属中的感染率明显高于血蜱属（p<0.05）。gltA 和 ompA 基因的序列分析表明，在青海省的蜱中存在五种 SFG 立克次体，包括西伯利亚立克次体亚种、拉乌尔立克次体、“西藏候选立克次体”和“甘肃候选立克次体”Y27 和 F107。此外，在努氏钝缘蜱和三棘血蜱中还鉴定出一种潜在的新型立克次体（10CYF 立克次体）。这些发现扩展了我们对立克次体潜在媒介谱和分布的认识，并为评估公共卫生的潜在风险提供了有价值的信息。
