Urovirulence and fimbrial regulation in Klebsiella quasipneumoniae

准肺炎克雷伯菌的尿毒力和菌毛调节

基本信息

批准号：
10742629
负责人：
Nicole Janell De Nisco
金额：
$ 25.27万
依托单位：
UNIVERSITY OF TEXAS DALLAS
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-18 至 2025-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10742629
关键词：
Acute Acute Cystitis Adult Affect Age Animal Model Antibiotic Resistance Antimicrobial Resistance Bacteria Bacterial Adhesion Bacterial Infections Benchmarking Binding Biological Assay Bladder C-terminal C3H/HeN Mouse Clinical Confocal Microscopy Cystitis DNA Binding Domain Enterobacteriaceae Epithelial Cells Epithelium Escherichia coli Exhibits Genes Genome Genomics Gentamicins Goals Health Hour Human Hybrids In Vitro Infection Infective cystitis Invaded Kidney Klebsiella Klebsiella pneumoniae Knowledge Lung Measurement Measures Mediating Menopausal Status Metabolic Metadata Methods Mining Mobile Genetic Elements Modeling Multi-Drug Resistance Mus N-terminal Nucleic Acid Regulatory Sequences Operon Patients Periodicity Persons Phenotype Play Prevalence Publishing Quality of life Recurrence Regulation Role Sequence Alignment Sequence Analysis Site Structure Surface Surgical Wound Infection System Urethra Urinary tract Urinary tract infection Urine Uropathogen Uropathogenic E. coli Virulence Virulence Factors Woman Work bacterial community biobank defined contribution experience genome sequencing human disease human pathogen mouse model nanopore phosphoric diester hydrolase resistance gene type 1 fimbriae urovirulent isolates whole genome

项目摘要

Project Summary Urinary tract infection (UTI) and recurrent UTI (rUTI) significantly reduces the quality of life of millions of women annually and poses a growing health threat due to the increasing prevalence of antibiotic resistant uropathogenic bacteria. Klebsiella spp. represent the second most common bacterial species isolated from the urine of women experiencing rUTI but have been largely understudied in the context of rUTI. Within the Klebsiella genus, Klebsiella pneumoniae is one of the most common human pathogens; however, genome sequence analysis has revealed that that K. pneumoniae isolates encompass at least three distinct species: K. pneumoniae, K. variicola and K. quasipneumoniae. Although K. quasipneumoniae strains are commonly isolated from patients with UTI and encode known virulence factors and antimicrobial resistance genes, no study has evaluated urovirulence phenotypes of K. quasipneumoniae in an animal model. Indeed, the clinical prevalence of K. quasipneumoniae in UTI remains unknown. Among the virulence factors that Klebsiella spp. possess, type 1 (fim operon) and type 3 (mrk operon) fimbriae play a crucial role in mediating bacterial adhesion and invasion of host epithelial surfaces. Type 1 fimbriae are widely conserved among Enterobacteriaceae, but the presence of the gene fimK differentiates the fim operons of Klebsiella spp. from Escherichia coli. In K. pneumoniae, FimK is a regulator of fim operon expression and is comprised of an N-terminal DNA binding domain that binds the fimS regulatory region and a conserved C-terminal EAL domain with phosphodiesterase activity. Through sequence alignment of the fim operons of sequenced K. quasipneumoniae and K. pneumoniae isolates, we have discovered that the fimK gene of K. quasipneumoniae is truncated and lacks the C-terminal EAL domain. This is important because not only is fimK a key regulator of fim operon expression, but it is also proposed to co-regulate mrk operon expression by modulation of cyclic di-GMP levels through its phosphodiesterase activity. We have found that FimK-mediated regulation of type 1 and type 3 fimbriae is distinct in K. quasipneumoniae due to the absence of the FimK EAL domain. We hypothesize that because of this regulatory difference, bladder infection dynamics and the requirement for type 1 versus type 3 fimbriae for bladder colonization may be distinct in K. quasipneumoniae. This proposal will address these hypotheses and produce foundational knowledge of K. quasipneumoniae bladder infection dynamics by i) defining the clinical prevalence of K. quasipneumoniae in UTI in women, ii) evaluating K. quasipneumoniae rUTI isolates in a mouse model of acute UTI, and iii) evaluating the role of K. quasipneumoniae type 1 versus type 3 fimbriae and FimK during acute UTI. Taken together, this work will produce the first foundational knowledge of clinical prevalence and bladder infection dynamics of the understudied human uropathogen K. quasipneumoniae and define the impact of the conserved truncation of the fimbrial regulator FimK on the regulation of type 1 and type 3 fimbriae and bladder colonization.

项目概要尿路感染 (UTI) 和复发性尿路感染 (rUTI) 显着降低了数百万人的生活质量由于抗生素耐药性的日益流行，妇女的健康威胁日益严重泌尿道致病细菌。克雷伯菌属代表从细菌中分离出的第二个最常见的细菌种类患有 rUTI 的女性的尿液，但在 rUTI 的背景下大部分都没有得到充分研究。克雷伯氏菌内属，肺炎克雷伯菌是最常见的人类病原体之一；然而，基因组序列分析表明，肺炎克雷伯菌分离株至少包含三个不同的物种：克雷伯菌。肺炎克雷伯菌、水痘克雷伯菌和准肺炎克雷伯菌。尽管准肺炎克雷伯菌菌株通常是分离的来自尿路感染患者并编码已知的毒力因子和抗菌素耐药基因，但没有研究表明在动物模型中评估了准肺炎克雷伯菌的尿毒力表型。事实上，临床上的患病率类肺炎克雷伯菌在尿路感染中的作用仍不清楚。克雷伯菌属的毒力因子之一。拥有 1 型（fim 操纵子）和 3 型（mrk 操纵子）菌毛在介导细菌粘附和入侵宿主上皮表面方面发挥着至关重要的作用。类型1 菌毛在肠杆菌科中广泛保守，但基因 fimK 的存在将其区分开来。克雷伯菌属 fim 操纵子。来自大肠杆菌。在肺炎克雷伯菌中，FimK 是 fim 操纵子的调节因子表达，由结合 fimS 调节区的 N 端 DNA 结合域和具有磷酸二酯酶活性的保守 C 端 EAL 结构域。通过fim的序列比对通过对已测序的准肺炎克雷伯菌和肺炎克雷伯菌分离株的操纵子进行分析，我们发现 fimK 基因准肺炎克雷伯菌的 C 端 EAL 结构域被截短。这很重要，因为不仅 fimK 是 fim 操纵子表达的关键调节因子，但也有人提出通过以下方式共同调节 mrk 操纵子表达：通过其磷酸二酯酶活性调节环二 GMP 水平。我们发现FimK介导的由于缺乏 FimK EAL，准肺炎克雷伯菌对 1 型和 3 型菌毛的调节是不同的领域。我们假设，由于这种监管差异，膀胱感染动态和准肺炎克雷伯菌膀胱定植对 1 型菌毛和 3 型菌毛的要求可能不同。该提案将解决这些假设并产生 K 的基础知识。准肺炎克雷伯氏菌膀胱感染动态，通过 i) 定义尿路感染中准肺炎克雷伯菌的临床患病率在女性中，ii) 评估急性 UTI 小鼠模型中的类肺炎克雷伯菌 rUTI 分离株，以及 iii) 评估 1 型准肺炎克雷伯菌与 3 型菌毛和 FimK 在急性 UTI 期间的作用。综合起来，这这项工作将产生关于临床患病率和膀胱感染动态的第一个基础知识正在研究的人类尿路病原体准肺炎克雷伯氏菌的研究并定义保守截断的影响菌毛调节因子 FimK 对 1 型和 3 型菌毛和膀胱定植的调节。