Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA.
Int J Mol Sci. 2017 Sep 30;18(10):2077. doi: 10.3390/ijms18102077.
One of the most common urologic problems afflicting millions of people worldwide is urinary tract infection (UTI). The severity of UTIs ranges from asymptomatic bacteriuria to acute cystitis, and in severe cases, pyelonephritis and urosepsis. The primary cause of UTIs is uropathogenic (UPEC), for which current antibiotic therapies often fail. UPEC forms multicellular communities known as biofilms on urinary catheters, as well as on and within bladder epithelial cells. Biofilm formation protects UPEC from environmental conditions, antimicrobial therapy, and the host immune system. Previous studies have investigated UPEC biofilm formation in aerobic conditions (21% oxygen); however, urine oxygen tension is reduced (4-6%), and urine contains molecules that can be used by UPEC as alternative terminal electron acceptors (ATEAs) for respiration. This study was designed to determine whether these different terminal electron acceptors utilized by influence biofilm formation. A panel of 50 urine-associated isolates was tested for the ability to form biofilm under anaerobic conditions and in the presence of ATEAs. Biofilm production was reduced under all tested sub-atmospheric levels of oxygen, with the notable exception of 4% oxygen, the reported concentration of oxygen within the bladder.
全世界数百万人都受到一种常见泌尿科问题的困扰，即尿路感染（UTI）。UTI 的严重程度从无症状菌尿到急性膀胱炎不等，严重情况下会发展为肾盂肾炎和脓毒症。UTI 的主要病因是尿路致病性大肠杆菌（UPEC），目前的抗生素疗法通常对此无效。UPEC 会在导尿管以及膀胱上皮细胞上形成称为生物膜的多细胞群落。生物膜的形成可保护 UPEC 免受环境条件、抗菌治疗和宿主免疫系统的影响。先前的研究已经在有氧条件（21%氧气）下研究了 UPEC 生物膜的形成；然而，尿液中的氧气张力会降低（4-6%），并且尿液中含有可被 UPEC 用作替代末端电子受体（ATEAs）进行呼吸的分子。本研究旨在确定这些不同的末端电子受体是否会影响生物膜的形成。测试了一组 50 种与尿液相关的 分离株在厌氧条件下和存在 ATEAs 时形成生物膜的能力。在所有测试的亚大气氧水平下，生物膜的产生均减少，只有 4%的氧气是个例外，这是膀胱内报告的氧气浓度。
