Urinary Tract Infection: Pathogenesis and Outlook.
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ABSTRACT:
SUBMITTER: McLellan LK
PROVIDER: S-EPMC5159206 | biostudies-literature | 2016 Nov
REPOSITORIES: biostudies-literature
Publications
Urinary Tract Infection: Pathogenesis and Outlook.
McLellan Lisa K LK Hunstad David A DA
Trends in molecular medicine 20160928 11
The clinical syndromes comprising urinary tract infection (UTI) continue to exert significant impact on millions of patients worldwide, most of whom are otherwise healthy women. Antibiotic therapy for acute cystitis does not prevent recurrences, which plague up to one fourth of women after an initial UTI. Rising antimicrobial resistance among uropathogenic bacteria further complicates therapeutic decisions, necessitating new approaches based on fundamental biological investigation. In this revie ...[more]
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Project description:BackgroundUropathogenic Escherichia coli (UPEC) is the most common agent of urinary tract infection (UTI). The classic model of pathogenesis proposes the ascent of UPEC by the urethra and external adherence to the urothelium. Recently, the ability of UPEC to invade urothelial cells and to form intracellular bacterial communities (IBCs) has been described.MethodsThe objective of the present study was to determine the presence of intracellular bacteria (IB) in children with UTI caused by E. coli and to characterize its virulence attributes and its relation with clinical outcomes. One hundred thirty-three children with E. coli UTI who attended a reference children's hospital between June and November 2012 were included. Urine samples were analyzed by optical and confocal microscopy looking for exfoliated urothelial cells with IB. Phylogenetic group and 24 virulence factors of UPEC were determined using multiplex polymerase chain reaction. Medical records were analyzed.ResultsThe presence of IB was detected in 49 of 133 (36.8%) samples by confocal microscopy, in 30 cases as IBC, and in 19 as isolated intracellular bacteria (IIB). Only 50% of these cases could be detected by light microscopy. Seventy-four medical records were analyzed, 34 with IBC/IIB, 40 without IB. Any virulence gene was associated with IBC/IIB. The presence of IBC/IIB was associated with recurrent UTI (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.3-9; P = .017), especially in children without urinary tract functional or morphological abnormalities (OR, 8.0; 95% CI, 2.3-27.4; P = .000). IBCs were associated with lower urinary tract syndrome (OR, 3.6; 95% CI, 1.1-11.8; P = .05) and absence of fever (P = .009).ConclusionsIBCs/IIB could explain a high proportion of children with recurrent UTI.
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Project description:Staphylococcus saprophyticus is a uropathogenic Staphylococcus frequently isolated from young female outpatients presenting with uncomplicated urinary tract infections. We sequenced the whole genome of S. saprophyticus type strain ATCC 15305, which harbors a circular chromosome of 2,516,575 bp with 2,446 ORFs and two plasmids. Comparative genomic analyses with the strains of two other species, Staphylococcus aureus and Staphylococcus epidermidis, as well as experimental data, revealed the following characteristics of the S. saprophyticus genome. S. saprophyticus does not possess any virulence factors found in S. aureus, such as coagulase, enterotoxins, exoenzymes, and extracellular matrix-binding proteins, although it does have a remarkable paralog expansion of transport systems related to highly variable ion contents in the urinary environment. A further unique feature is that only a single ORF is predictable as a cell wall-anchored protein, and it shows positive hemagglutination and adherence to human bladder cell associated with initial colonization in the urinary tract. It also shows significantly high urease activity in S. saprophyticus. The uropathogenicity of S. saprophyticus can be attributed to its genome that is needed for its survival in the human urinary tract by means of novel cell wall-anchored adhesin and redundant uro-adaptive transport systems, together with urease.
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Project description: Not available
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Project description:BackgroundAmong older adults, postoperative urinary tract infection is associated with significant harms including increased risk of hospital readmission and perioperative mortality. While risk of urinary tract infection is known to increase with age, the independent association between frailty and postoperative urinary tract infection is unknown. In this study we used 2014-2018 data from the U.S. National Surgical Quality Improvement Program (NSQIP) to investigate whether frailty is an independent risk factor for postoperative urinary tract infection, controlling for age and other relevant confounders.MethodsFrailty was assessed using the modified Frailty Index. Postoperative urinary tract infection was defined as any symptomatic urinary tract infection (of the kidneys, ureters, bladder, or urethra) developing within 30 days of the operative procedure. To examine associations between frailty and other specific factors and postoperative urinary tract infection, chi squared tests, students t-tests, and logistic regression modelling were used.ResultsUrinary tract infection was identified after 22,356 of 1,724,042 procedures (1.3%). In a multivariable model controlling for age and other patient and surgical characteristics, the relative odds for urinary tract infection increased significantly with increasing frailty score. For example, compared to a frailty score of 0, the relative odds for urinary tract infection for a frailty score of 3 was 1.50 (95% confidence interval 1.41, 1.60). The relative odds associated with the maximum frailty score (5) was 2.50 (95% confidence interval 1.73, 3.61).ConclusionsFrailty is associated with postoperative urinary tract infection, independent of age. Further research should focus on the underlying mechanisms and strategies to mitigate this risk among frail adults.
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