Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana, USA.
Appl Environ Microbiol. 2021 Jul 27;87(16):e0074421. doi: 10.1128/AEM.00744-21.
Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) is an emerging cause of hospital-associated urinary tract infections (UTI), especially in catheterized individuals. Despite being rare, MRSA UTI are prone to potentially life-threatening exacerbations such as bacteremia that can be refractory to routine antibiotic therapy. To delineate the molecular mechanisms governing MRSA urinary pathogenesis, we exposed three S. aureus clinical isolates, including two MRSA strains, to human urine for 2 h and analyzed virulence characteristics and changes in gene expression. The virulence assays showed that human urine rapidly alters adherence to human bladder epithelial cells and fibronectin, hemolysis of sheep red blood cells (RBCs), and surface hydrophobicity in a staphylococcal strain-specific manner. In addition, transcriptome sequencing (RNA-Seq) analysis of uropathogenic strain MRSA-1369 revealed that 2-h-long exposure to human urine alters MRSA transcriptome by modifying expression of genes encoding enzymes catalyzing metabolic pathways, virulence factors, and transcriptional regulators. In summary, our results provide important insights into how human urine specifically and rapidly alters MRSA physiology and facilitates MRSA survival in the nutrient-limiting and hostile urinary microenvironment. Methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon cause of urinary tract infections (UTI) in the general population. However, it is important to understand MRSA pathophysiology in the urinary tract because isolation of MRSA in urine samples often precedes potentially life-threatening MRSA bacteremia. In this report, we describe how exposure to human urine alters MRSA global gene expression and virulence. We hypothesize that these alterations may aid MRSA in acclimating to the nutrient-limiting, immunologically hostile conditions within the urinary tract leading to MRSA UTI.
耐甲氧西林金黄色葡萄球菌(MRSA)是一种新兴的医院相关尿路感染(UTI)病原体,尤其在导尿管相关个体中更为常见。尽管MRSA 引起的 UTI 较为罕见,但它们容易发生潜在的危及生命的并发症,如菌血症,而且可能对常规抗生素治疗产生耐药。为了阐明MRSA 尿路发病机制的分子机制,我们将三种金黄色葡萄球菌临床分离株(包括两种 MRSA 菌株)暴露于人尿液中 2 小时,然后分析其毒力特征和基因表达变化。毒力测定表明,人尿液能够以菌株特异性的方式迅速改变对人膀胱上皮细胞和纤维连接蛋白的黏附能力、绵羊红细胞(RBC)的溶血能力和表面疏水性。此外,对尿路致病性菌株 MRSA-1369 的转录组测序(RNA-Seq)分析表明,2 小时的人尿液暴露会通过改变编码代谢途径、毒力因子和转录调节因子的基因表达来改变 MRSA 的转录组。总之,我们的结果提供了重要的见解,即人尿液如何特异性且迅速地改变 MRSA 的生理学特性,并促进 MRSA 在营养有限和具有免疫原性的尿液微环境中的存活。
耐甲氧西林金黄色葡萄球菌(MRSA)在普通人群中是一种罕见的尿路感染(UTI)病原体。然而,了解 MRSA 在泌尿道中的病理生理学非常重要,因为尿液样本中分离出 MRSA 通常先于潜在的危及生命的 MRSA 菌血症。在本报告中,我们描述了暴露于人尿液如何改变 MRSA 的全局基因表达和毒力。我们假设这些改变可能有助于 MRSA 适应尿液中营养有限、免疫原性恶劣的条件,从而导致 MRSA UTI。