The Ecology and Classification of Rickettsia Species Phylotype G022, an Uncharacterized Bacterium from Ixodes pacificus Ticks

太平洋硬蜱未定性细菌立克次体种系型 G022 的生态学和分类

• 批准号: 10412445
• 负责人: Jianmin Zhong
• 金额: $ 14.75万
• 依托单位: HUMBOLDT STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-12 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10412445
• 关键词: Adult; Anaplasmosis; Animals; Arthropods; Bacteria; Biological Assay; Biology; Black-legged Tick; Bobcat; California; Canis familiaris; Cell Line; Centers for Disease Control and Prevention (U.S.); Classification; County; DNA; Dangerousness; Data; Diagnosis; Domestic Animals; Ecology; Educational Curriculum; Exanthema; Exposure to; Felis catus; Fever; Foxes; Funding; Genomics; Goals; Hispanic-serving Institution; Human; Infection; Ixodes; Ixodidae; Learning; Life; Low Prevalence; Lyme Disease; Medical; Methods; Molecular; Names; New Zealand; North America; Northern America; Nymph; Oryctolagus cuniculus; Outcome; Pathogenesis; Pathogenicity; Persons; Phylogenetic Analysis; Prevalence; Proteomics; Public Health; Publishing; Reporting; Research; Rickettsia; Rickettsia Infections; Route; Rural Community; Science; Students; Surveys; Symptoms; Tick-Borne Diseases; Ticks; Time; Training; Trees; United States; Universities; Work; blastomere structure; cost; detection method; experience; exposed human population; feeding; graduate student; human disease; infection rate; infection risk; insight; lower income families; next generation sequencing; novel; pathogen; serosurvey; spotted fever; success; tick bite; tick-borne; tick-borne pathogen; transmission process; undergraduate student; underrepresented minority student; vector

Project Summary/Abstract While both ticks and tick-borne disease agents have rapidly become a serious and growing threat to human and veterinary public health, mounting evidence indicates that many tick-borne diseases due to rickettsial infection may be under-reported in Northern America because of their uncharacteristic symptoms in humans and domestic animals. Ixodes pacificus is a principal vector for pathogenic and endosymbiotic bacteria on the Pacific West Coast of the United States. Compared to pathogenic rickettsiae identified in other tick species in California, the ecology and biology of pathogenic rickettsiae in I. pacificus remains largely unexplored. Our lab detected a novel Rickettsia species, Rickettsia species phylotype G022, in questing adult ticks of I. pacificus in three counties of Northern California in 2011, 2013, and 2020. Due to phylotype G022’s low prevalence (2-4.5%) in adult I. pacificus and published phylogenetic trees placing the bacterium within other pathogenic spotted fever group rickettsiae, our hypothesis is that phylotype G022 is a pathogenic Rickettsia. The proposed study ultimately serves as a continuation of our previous findings regarding the ecology and pathogenesis of Rickettsia species in I. pacificus. Our research pursues the following specific aims: 1) We will conduct a survey to estimate the prevalence of Rickettsia species phylotype G022 in nymphal ticks of I. pacificus by collecting the nymphs from the field and detecting the bacterium by real-time PCR; 2) We will study transmission routes of Rickettsia species phylotype G022 in I. pacificus by collecting all life stages of the ticks via feeding on New Zealand white rabbits and detecting the bacterium by real-time PCR; 3) We will perform the propagation and isolation of the Rickettsia phylotype G022 isolate from I. pacificus using tick embryonic cell lines and limiting dilution assay; 4) We will perform the molecular typing of the Rickettsia species phylotype G022 isolate by Multilocus Sequence Typing; 5) We will investigate the presence of Rickettsia species phylotype G022 infection in domestic dogs from Northern California. This study will not only result in the official naming of phylotype G022 by typing the pure bacterial isolate, but also enable us to start gathering data on transmission dynamics of the bacterium as well as its potential pathogenicity, the long-term research goal of our lab, to humans and animal hosts in Northern California.

项目概要/摘要 虽然蜱虫和蜱传疾病媒介已迅速成为对人类和人类的严重且日益严重的威胁 兽医公共卫生方面，越来越多的证据表明，许多由立克次体感染引起的蜱传疾病可能是由立克次体感染引起的。 由于硬蜱在人类和家畜中表现出不典型的症状，因此在北美未被充分报道。 pacificus 是美国太平洋西海岸致病菌和内共生菌的主要载体。 与加州其他蜱种中发现的致病性立克次体相比，致病性立克次体的生态学和生物学 太平洋立克次体中的立克次体在很大程度上尚未被探索过。我们的实验室检测到了一种新的立克次体物种，即立克次体物种。 系统发育型 G022，于 2011 年、2013 年和 2020 年在北加州三个县调查 I. pacificus 成年蜱。 由于系统发育型 G022 在成年 I. pacificus 中的流行率较低 (2-4.5%)，并且已发表的系统发育树将 其他致病性斑疹热群立克次氏体中的细菌，我们的假设是系统发育型 G022 是一种致病性 拟议的研究最终是我们之前关于立克次体的生态和研究结果的延续。 太平洋立克次体的发病机制 我们的研究追求以下具体目标： 1) 我们将进行一项研究。 通过收集太平洋立克次体种属系统型 G022 在太平洋若虫蜱中的流行率进行调查 2）研究立克次体的传播途径； 通过喂养新西兰白兔收集蜱虫的所有生命阶段，确定 I. pacificus 的物种系统型 G022 并通过实时PCR检测细菌；3）我们将进行立克次体的繁殖和分离。 使用蜱胚胎细胞系和有限稀释测定从 I. pacificus 中分离出系统型 G022；4) 我们将进行 通过多位点序列分型对立克次体种系型 G022 分离株进行分子分型 5) 我们将； 调查北加州家犬中是否存在立克次体种系型 G022 感染。 研究不仅将通过对纯细菌分离株进行分型来正式命名系统发育型 G022，而且使我们能够 为了开始收集有关细菌传播动力学及其潜在致病性的数据，长期 我们实验室的研究目标是北加州的人类和动物宿主。