Department of Microbiology and Immunology, University of Michigan Medical School, 5641 Medical Science Building II, 1150 West Medical Center Drive, Ann Arbor, MI 48109-0620, USA.
Nat Rev Urol. 2010 Aug;7(8):430-41. doi: 10.1038/nrurol.2010.101. Epub 2010 Jul 20.
The urinary tract is a common site of bacterial infections; nearly half of all women experience at least one urinary tract infection (UTI) during their lifetime. These infections are classified based on the condition of the host. Uncomplicated infections affect otherwise healthy individuals and are most commonly caused by uropathogenic Escherichia coli, whereas complicated infections affect patients with underlying difficulties, such as a urinary tract abnormality or catheterization, and are commonly caused by species such as Proteus mirabilis. Virulence and fitness factors produced by both pathogens include fimbriae, toxins, flagella, iron acquisition systems, and proteins that function in immune evasion. Additional factors that contribute to infection include the formation of intracellular bacterial communities by E. coli and the production of urease by P. mirabilis, which can result in urinary stone formation. Innate immune responses are induced or mediated by pattern recognition receptors, antimicrobial peptides, and neutrophils. The adaptive immune response to UTI is less well understood. Host factors TLR4 and CXCR1 are implicated in disease outcome and susceptibility, respectively. Low levels of TLR4 are associated with asymptomatic bacteriuria while low levels of CXCR1 are associated with increased incidence of acute pyelonephritis. Current research is focused on the identification of additional virulence factors and therapeutic or prophylactic targets that might be used in the generation of vaccines against both uropathogens.
尿路是细菌感染的常见部位；几乎一半的女性在其一生中至少会经历一次尿路感染（UTI）。这些感染根据宿主的情况进行分类。非复杂性感染影响健康个体，最常见的病原体是尿路致病性大肠杆菌，而复杂性感染影响存在潜在困难的患者，如尿路异常或导管插入，常见病原体如奇异变形杆菌。两种病原体产生的毒力和适应性因素包括菌毛、毒素、鞭毛、铁获取系统以及在免疫逃避中发挥作用的蛋白质。有助于感染的其他因素包括大肠杆菌形成细胞内细菌群落和奇异变形杆菌产生脲酶，这可能导致尿路结石形成。先天免疫反应由模式识别受体、抗菌肽和中性粒细胞诱导或介导。对 UTI 的适应性免疫反应了解较少。宿主因素 TLR4 和 CXCR1 分别与疾病结局和易感性有关。TLR4 水平低与无症状菌尿有关，而 CXCR1 水平低与急性肾盂肾炎的发生率增加有关。目前的研究集中在鉴定其他毒力因子和治疗或预防靶点，这些可能用于开发针对尿路病原体的疫苗。
