Characterization of viridans group streptococci from endophthalmitis

项目总结/摘要 草绿色链球菌通常被认为是具有致龋潜力的口腔链球菌;然而，这些 细菌也被列为引起细菌性眼内炎的最常见物种。外源 细菌性眼内炎可在外伤、眼部手术或眼部注射后发生。使用抗生素 然而，为了治疗这种疾病，抗生素只能杀死细菌，而不能减轻对 the eye.特别是链球菌与非常差的视力结果相关;尽管进行了治疗， 通常会发生内脏摘除或眼球摘除。本申请的直接目标是表征 草绿色链球菌眼内炎菌株的分离及毒力因子的鉴定。这一目标 旨在启动对确定发病机制的更广泛的长期目标的研究 并确定未来治疗的潜在目标。两个主要目标是 目的：1）探讨细菌蛋白酶HtrA在眼内炎中的作用， 细菌蛋白质底物，和2）分析眼内炎的泛基因组和毒力转录组- 引起紧张。第一个目的将通过从大肠杆菌中克隆的重组HtrA变体的功能分析来测试。 通过从htrA阳性菌株中缺失突变htrA，以及遗传添加 htrA至htrA阴性菌株。第二个目标将采用21种菌株的全基因组测序， 生物信息学泛基因组分析，以确定整个集合中的保守基因，以及体内RNA-seq， 在体外，以确定这组物种的毒力转录组。实现这些目标将 跳板识别这些物种眼部感染的关键因素。本研究是 预期长期有益于患者的眼部健康，因为获得的知识可以帮助未来 治疗发展

Project Summary/Abstract The viridans streptococci are classically considered oral commensals with cariogenic potential; however, these bacteria are also listed among the most common species that cause bacterial endophthalmitis. Exogenous bacterial endophthalmitis can occur following trauma, ocular surgery, or ocular injections. Antibiotics are used to treat this disease, however, antibiotics are only able to kill the bacteria and do not ameliorate the damage to the eye. Streptococcal species in particular are associated with very poor visual outcomes; despite treatment, evisceration or enucleation commonly occur. The immediate objective of this application is to characterize endophthalmitis strains of the viridans streptococci and identify their virulence factors. This objective is intended to initiate study into the broader, long-term objectives of determining the mechanisms of pathogenesis of this important group of species and identify potential targets for future therapies. Two major aims are proposed: 1) to investigate the role of bacterial protease HtrA in endophthalmitis and determine its vitreous and bacterial protein substrates, and 2) to analyze the pangenome and virulence transcriptome of endophthalmitis- causing strains. The first aim will be tested by function analysis of recombinant HtrA variants cloned from the viridans strains and by deletion mutagenesis of htrA from htrA-positive strains, as well as genetic addition of htrA to htrA-negative strains. The second aim will employ whole genome sequencing of 21 strains followed by bioinformatics pangenome analysis to identify conserved genes across the collection, and RNA-seq in vivo and in vitro to determine the virulence transcriptome of this group of species. Accomplishment of these aims will springboard the identification of key factors involved in ocular infection by these species. This research is expected to benefit patient ocular health in the long-term because the knowledge to be gained can aid future therapeutic development.