背景:立克次体和相关疾病已被确定为重大的全球公共卫生威胁。本研究涉及云南省各种立克次体生物的全面实地和系统调查。
方法:2011年5月18日至2020年11月23日,对云南省42个县进行了实地调查,中国,包括小型哺乳动物,牲畜,和蜱。Rickettsiales的初步筛选涉及扩增16SrRNA基因,以及其他属或物种特异性基因,随后通过测序结果得到证实。使用基本局部比对搜索工具(BLAST)进行序列比较。使用分子进化遗传学分析(MEGA)程序中的默认参数分析系统发生关系。卡方检验用于评估立克次体药物在各种参数中的多样性和组成比。
结果:从小型哺乳动物中收集了7964个样本,牲畜,并通过云南省进行滴答,并提交筛选立克次体生物。立克次体属的16种立克次体,解脲脲,埃里希亚,Neoehrlichia,和Wolbachia被发现,总体患病率为14.72%。其中,11种被鉴定为人类和家畜的病原体或潜在病原体。具体来说,在42.11%(57个中的24个)的小哺乳动物物种中广泛发现了10个立克次体生物。在Dremomys样本中观察到高患病率为5.60%,在纬度超过4000米的地区或高山草甸的样本中,以及从元谋县获得的。吞噬菌体和念珠菌被广泛感染动物宿主的多个属。相比之下,小型哺乳动物Neodon属,梦幻般的,奥乔托纳,阿努罗索雷克斯,Mus携带了个别特定的立克次体药剂,表明宿主倾向。在57.14%(14个中有8个)的蜱中检测到13个立克次体,在Rhipicephalus属中观察到的患病率最高(37.07%)。在2375个牲畜样本中鉴定出8种立克次体。值得注意的是,发现了六种新的Rickettsiales变体/菌株,明确鉴定了长尾立克次体。
结论:这项大规模调查进一步了解了云南省流行热点地区新兴立克次体病的高遗传多样性和总体患病率。这些新兴的蜱虫传播的Rickettsiales对公共卫生构成的潜在威胁值得关注,强调需要有效的策略来指导中国新兴的人畜共患疾病的预防和控制。
BACKGROUND: Rickettsia and related diseases have been identified as significant global public health threats. This study involved comprehensive field and systematic investigations of various rickettsial organisms in Yunnan Province.
METHODS: Between May 18, 2011 and November 23, 2020, field investigations were conducted across 42 counties in Yunnan Province,
China, encompassing small mammals, livestock, and ticks. Preliminary screenings for
Rickettsiales involved amplifying the 16S rRNA genes, along with additional genus- or species-specific genes, which were subsequently confirmed through sequencing results. Sequence comparisons were carried out using the Basic Local Alignment Search Tool (BLAST). Phylogenetic relationships were analyzed using the default parameters in the Molecular Evolutionary Genetics Analysis (MEGA) program. The chi-squared test was used to assess the diversities and component ratios of rickettsial agents across various parameters.
RESULTS: A total of 7964 samples were collected from small mammals, livestock, and ticks through Yunnan Province and submitted for screening for rickettsial organisms. Sixteen rickettsial species from the genera Rickettsia, Anaplasma, Ehrlichia, Neoehrlichia, and Wolbachia were detected, with an overall prevalence of 14.72%. Among these, 11 species were identified as pathogens or potential pathogens to humans and livestock. Specifically, 10 rickettsial organisms were widely found in 42.11% (24 out of 57) of small mammal species. High prevalence was observed in Dremomys samples at 5.60%, in samples from regions with latitudes above 4000 m or alpine meadows, and in those obtained from Yuanmou County. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis were broadly infecting multiple genera of animal hosts. In contrast, the small mammal genera Neodon, Dremomys, Ochotona, Anourosorex, and Mus were carrying individually specific rickettsial agents, indicating host tropism. There were 13 rickettsial species detected in 57.14% (8 out of 14) of tick species, with the highest prevalence (37.07%) observed in the genus Rhipicephalus. Eight rickettsial species were identified in 2375 livestock samples. Notably, six new
Rickettsiales variants/strains were discovered, and Candidatus Rickettsia longicornii was unambiguously identified.
CONCLUSIONS: This large-scale survey provided further insight into the high genetic diversity and overall prevalence of emerging Rickettsiales within endemic hotspots in Yunnan Province. The potential threats posed by these emerging tick-borne
Rickettsiales to public health warrant attention, underscoring the need for effective strategies to guide the prevention and control of emerging zoonotic diseases in
China.