scholarly journals Enterococcal Biofilm Formation and Virulence in an Optimized Murine Model of Foreign Body-Associated Urinary Tract Infections

2010 ◽  
Vol 78 (10) ◽  
pp. 4166-4175 ◽  
Author(s):  
Pascale S. Guiton ◽  
Chia S. Hung ◽  
Lynn E. Hancock ◽  
Michael G. Caparon ◽  
Scott J. Hultgren
Keyword(s):  
Urinary Tract ◽  
Foreign Body ◽  
Urinary Tract Infections ◽  
Murine Model ◽  
Biofilm Formation ◽  
Significant Advance ◽  
Virulence Determinants ◽  
Indwelling Catheters ◽  
Tract Infections

ABSTRACT Catheter-associated urinary tract infections (CAUTIs) constitute the majority of nosocomial UTIs and pose significant clinical challenges. Enterococcal species are among the predominant causative agents of CAUTIs. However, very little is known about the pathophysiology of Enterococcus-mediated UTIs. We optimized a murine model of foreign body-associated UTI in order to mimic conditions of indwelling catheters in patients. In this model, the presence of a foreign body elicits major histological changes and induces the expression of several proinflammatory cytokines in the bladder. In addition, in contrast to naïve mice, infection of catheter-implanted mice with Enterococcus faecalis induced the specific expression of interleukin 1β (IL-1β) and macrophage inflammatory protein 1α (MIP-1α) in the bladder. These responses resulted in a favorable niche for the development of persistent E. faecalis infections in the murine bladders and kidneys. Furthermore, biofilm formation on the catheter implant in vivo correlated with persistent infections. However, the enterococcal autolytic factors GelE and Atn (also known as AtlA), which are important in biofilm formation in vitro, are dispensable in vivo. In contrast, the housekeeping sortase A (SrtA) is critical for biofilm formation and virulence in CAUTIs. Overall, this murine model represents a significant advance in the understanding of CAUTIs and underscores the importance of urinary catheterization during E. faecalis uropathogenesis. This model is also a valuable tool for the identification of virulence determinants that can serve as potential antimicrobial targets for the treatment of enterococcal infections.

scholarly journals Identification of virulence determinants in uropathogenic Proteus mirabilis using signature-tagged mutagenesis

2008 ◽  
Vol 57 (9) ◽  
pp. 1068-1078 ◽  
Author(s):  
Stephanie D. Himpsl ◽  
C. Virginia Lockatell ◽  
J. Richard Hebel ◽  
David E. Johnson ◽  
Harry L. T. Mobley
Keyword(s):  
Urinary Tract ◽  
Mouse Model ◽  
Proteus Mirabilis ◽  
Virulence Determinants ◽  
Indwelling Catheters ◽  
Cba Mice ◽  
Transposon Mutants ◽  
Tract Infections

The Gram-negative bacterium Proteus mirabilis causes urinary tract infections (UTIs) in individuals with long-term indwelling catheters or those with functional or structural abnormalities of the urinary tract. Known virulence factors include urease, haemolysin, fimbriae, flagella, DsbA, a phosphate transporter and genes involved in cell-wall synthesis and metabolism, many of which have been identified using the technique of signature-tagged mutagenesis (STM). To identify additional virulence determinants and to increase the theoretical coverage of the genome, this study generated and assessed 1880 P. mirabilis strain HI4320 mutants using this method. Mutants with disruptions in genes vital for colonization of the CBA mouse model of ascending UTI were identified after performing primary and secondary in vivo screens in approximately 315 CBA mice, primary and secondary in vitro screens in both Luria broth and minimal A medium to eliminate mutants with minor growth deficiencies, and co-challenge competition experiments in approximately 500 CBA mice. After completion of in vivo screening, a total of 217 transposon mutants were attenuated in the CBA mouse model of ascending UTI. Following in vitro screening, this number was reduced to 196 transposon mutants with a probable role in virulence. Co-challenge competition experiments confirmed significant attenuation for 37 of the 93 transposon mutants tested, being outcompeted by wild-type HI4320. Following sequence analysis of the 37 mutants, transposon insertions were identified in genes including the peptidyl-prolyl isomerases surA and ppiA, glycosyltransferase cpsF, biopolymer transport protein exbD, transcriptional regulator nhaR, one putative fimbrial protein, flagellar M-ring protein fliF and hook protein flgE, and multiple metabolic genes.

scholarly journals Catheter-Associated Urinary Tract Infection by Pseudomonas aeruginosa Is Mediated by Exopolysaccharide-Independent Biofilms

2014 ◽  
Vol 82 (5) ◽  
pp. 2048-2058 ◽  
Author(s):  
Stephanie J. Cole ◽  
Angela R. Records ◽  
Mona W. Orr ◽  
Sara B. Linden ◽  
Vincent T. Lee
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Urinary Tract ◽  
Biofilm Formation ◽  
Extracellular Dna ◽  
Extracellular Polysaccharides ◽  
Indwelling Catheters ◽  
Content Type ◽  
Tract Infections

ABSTRACTPseudomonas aeruginosais an opportunistic human pathogen that is especially adept at forming surface-associated biofilms.P. aeruginosacauses catheter-associated urinary tract infections (CAUTIs) through biofilm formation on the surface of indwelling catheters.P. aeruginosaencodes three extracellular polysaccharides, PEL, PSL, and alginate, and utilizes the PEL and PSL polysaccharides to form biofilmsin vitro; however, the requirement of these polysaccharides duringin vivoinfections is not well understood. Here we show in a murine model of CAUTI that PAO1, a strain harboringpel,psl, andalggenes, and PA14, a strain harboringpelandalggenes, form biofilms on the implanted catheters. To determine the requirement of exopolysaccharide duringin vivobiofilm infections, we tested isogenic mutants lacking thepel,psl, andalgoperons and showed that PA14 mutants lacking these operons can successfully form biofilms on catheters in the CAUTI model. To determine the host factor(s) that induces the ΔpelDmutant to form biofilm, we tested mouse, human, and artificial urine and show that urine can induce biofilm formation by the PA14 ΔpelDmutant. By testing the major constituents of urine, we show that urea can induce apel-,psl-, andalg-independent biofilm. Thesepel-,psl-, andalg-independent biofilms are mediated by the release of extracellular DNA. Treatment of biofilms formed in urea with DNase I reduced the biofilm, indicating that extracellular DNA supports biofilm formation. Our results indicate that the opportunistic pathogenP. aeruginosautilizes a distinct program to form biofilms that are independent of exopolysaccharides during CAUTI.

scholarly journals Azithromycin-Ciprofloxacin-Impregnated Urinary Catheters Avert Bacterial Colonization, Biofilm Formation, and Inflammation in a Murine Model of Foreign-Body-Associated Urinary Tract Infections Caused by Pseudomonas aeruginosa

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Hina Saini ◽  
Anitha Vadekeetil ◽  
Sanjay Chhibber ◽  
Kusum Harjai
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Murine Model ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Silicone Implants ◽  
Urinary Catheters ◽  
Content Type ◽  
Tract Infections

ABSTRACT Pseudomonas aeruginosa is a multifaceted pathogen causing a variety of biofilm-mediated infections, including catheter-associated urinary tract infections (CAUTIs). The high prevalence of CAUTIs in hospitals, their clinical manifestations, such as urethritis, cystitis, pyelonephritis, meningitis, urosepsis, and death, and the associated economic challenges underscore the need for management of these infections. Biomaterial modification of urinary catheters with two drugs seems an interesting approach to combat CAUTIs by inhibiting biofilm. Previously, we demonstrated the in vitro efficacy of urinary catheters impregnated with azithromycin (AZM) and ciprofloxacin (CIP) against P. aeruginosa. Here, we report how these coated catheters impact the course of CAUTI induced by P. aeruginosa in a murine model. CAUTI was established in female LACA mice with uncoated or AZM-CIP-coated silicone implants in the bladder, followed by transurethral inoculation of 108 CFU/ml of biofilm cells of P. aeruginosa PAO1. AZM-CIP-coated implants (i) prevented biofilm formation on the implant's surface (P ≤ 0.01), (ii) restricted bacterial colonization in the bladder and kidney (P < 0.0001), (iii) averted bacteriuria (P < 0.0001), and (iv) exhibited no major histopathological changes for 28 days in comparison to uncoated implants, which showed persistent CAUTI. Antibiotic implants also overcame implant-mediated inflammation, as characterized by trivial levels of inflammatory markers such as malondialdehyde (P < 0.001), myeloperoxidase (P < 0.05), reactive oxygen species (P ≤ 0.001), and reactive nitrogen intermediates (P < 0.01) in comparison to those in uncoated implants. Further, AZM-CIP-coated implants showed immunomodulation by manipulating the release of inflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and IL-10 to the benefit of the host. Overall, the study demonstrates long-term in vivo effectiveness of AZM-CIP-impregnated catheters, which may possibly be a key to success in preventing CAUTIs.

Update on the Treatment of Bacterial Urinary Tract Infections

1981 ◽  
Vol 15 (10) ◽  
pp. 738-750 ◽  
Author(s):  
Neil Massoud
Keyword(s):  
Biological Activity ◽  
Single Dose ◽  
Urinary Tract ◽  
Patient Compliance ◽  
Urinary Tract Infections ◽  
Antimicrobial Agents ◽  
Complex Problem ◽  
Tract Infections

The treatment of urinary tract infections (UTIs) has become a complex problem for the clinical practitioner. An understanding of the pharmacology, pharmacokinetics, and in vivo biological activity of antimicrobial agents is needed, as is an understanding of the variables that may influence patient compliance with medication regimens. Although UTIs are usually treated for 10 to 14 days, shorter treatment schedules of seven to ten days or even single-dose regimens are possible. Guidelines for the treatment of UTIs are presented along with suggestions for increased patient compliance.

scholarly journals Quinolones for the Treatment ofNeisseria GonorrhoeaeandChlamydia Trachomatis

1993 ◽  
Vol 1 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Sebastian Faro
Keyword(s):  
Urinary Tract ◽  
Soft Tissue ◽  
Chlamydia Trachomatis ◽  
Urinary Tract Infections ◽  
Single Agent ◽  
Moderate Activity ◽  
Sexually Transmitted ◽  
Tract Infections

The most commonly sexually transmitted bacteria areNeisseria gonorrhoeaeandChlamydia trachomatis.The quinolones ofloxacin and ciprofloxacin have been shown to have activity against both of these bacteria in vitro and in vivo. Ofloxacin is particularly well suited for the treatment ofN. gonorrhoeaeandC. trachomatiscervical infection, which can be considered the earliest manifestation of pelvic inflammatory disease (PID). Not only can ofloxacin be effectively used as a single agent, it is also useful in treating urinary tract infections caused by Enterobacteriaceae. Although it has moderate activity against anaerobes in general, ofloxacin does have activity against the anaerobes commonly isolated from female patients with soft tissue pelvic infections. Thus, ofloxacin has the potential for being utilized to treat early salpingitis.

FimH Antagonists for the Oral Treatment of Urinary Tract Infections: From Design and Synthesis to in Vitro and in Vivo Evaluation

2010 ◽  
Vol 53 (24) ◽  
pp. 8627-8641 ◽  
Author(s):  
Tobias Klein ◽  
Daniela Abgottspon ◽  
Matthias Wittwer ◽  
Said Rabbani ◽  
Janno Herold ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Oral Treatment ◽  
In Vivo Evaluation ◽  
Design And Synthesis ◽  
Tract Infections

THE USE OF GAS-SENSOR ARRAYS TO DIAGNOSE URINARY TRACT INFECTIONS

2005 ◽  
Vol 15 (05) ◽  
pp. 363-376 ◽  
Author(s):  
VASSILIS KODOGIANNIS ◽  
EDMUND WADGE
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Electronic Nose ◽  
Radial Basis Function Network ◽  
Sensor Arrays ◽  
Test Tube ◽  
Classification Rate ◽  
Investigation Methods ◽  
Tract Infections

Sensorial analysis based on the utilisation of human senses, is one of the most important and straightforward investigation methods in food and chemical analysis. An electronic nose has been used to detect in vivo Urinary Tract Infections from 45 suspected cases that were sent for analysis in a UK Health Laboratory environment. These samples were analysed by incubation in a volatile generation test tube system for 4–5 h. The volatile production patterns were then analysed using an electronic nose system with 14 conducting polymer sensors. An intelligent model consisting of an odour generation mechanism, rapid volatile delivery and recovery system, and a classifier system based on learning techniques has been considered. The implementation of an Extended Normalised Radial Basis Function network with advanced features for determining its size and parameters and the concept of fusion of multiple classifiers dedicated to specific feature parameters has been also adopted in this study. The proposed scheme achieved a very high classification rate of the testing dataset, demonstrating in this way the efficiency of the proposed scheme compared with other approaches. This study has shown the potential for early detection of microbial contaminants in urine samples using electronic nose technology.

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