Article

Urinary tract infections caused by Pseudomonas aeruginosa: a minireview.

Division of Infectious Diseases, Childrens Hospital Los Angeles, Los Angeles, CA 90027, USA.
Journal of infection and public health 01/2009; 2(3):101-11. DOI: 10.1016/j.jiph.2009.08.003
Source: PubMed

ABSTRACT Urinary tract infections (UTIs) are a serious health problem affecting millions of people each year. Infections of the urinary tract are the second most common type of infection in the body. Catheterization of the urinary tract is the most common factor, which predisposes the host to these infections. Catheter-associated UTI (CAUTI) is responsible for 40% of nosocomial infections, making it the most common cause of nosocomial infection. CAUTI accounts for more than 1 million cases in hospitals and nursing homes annually and often involve uropathogens other than Escherichia coli. While the epidemiology and pathogenic mechanisms of uropathogenic Escherichia coli have been extensively studied, little is known about the pathogenesis of UTIs caused by other organisms like Pseudomonas aeruginosa. Scanty available information regarding pathogenesis of UTIs caused by P. aeruginosa is an important bottleneck in developing effective preventive approaches. The aim of this review is to summarize some of the advances made in the field of P. aeruginosa induced UTIs and draws attention of the workers that more basic research at the level of pathogenesis is needed so that novel strategies can be designed.

1 Bookmark
 · 
436 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the human pathogen Pseudomonas aeruginosa, the GltR regulator is required for glucose transport, whereas GtrS is a sensor kinase that plays a key role in mediating bacteria-host interaction and pathogen dissemination in the host. We show that GtrS and GltR form a two-component system that regulates the expression from the promoters Pedd/gap-1, PoprB and Pglk, which control the expression of genes involved in glucose metabolism and transport. In addition, the GtrS/GltR pair regulates the expression of toxA that encodes exotoxin A, the primary virulence factor. Microcalorimetry-based ligand screening of the recombinant GtrS ligand-binding domain revealed specific binding of 2-ketogluconate (2-KG) (KD = 5 μM) and 6-phosphogluconate (KD = 98 μM). These effectors accelerate GtrS autophosphorylation, with concomitant transphosphorylation of GltR leading to a three-fold increase in transcription. Surprisingly, in vivo a similar increase in expression from the above promoters was observed for the mutant deficient in GltR regardless of the presence of effectors. The GltR operator site was found to contain the consensus sequence 5'-tgGTTTTTc-3'. We propose that 2-KG is a key metabolite in the stringent transcriptional control of genes involved in virulence and glucose metabolism. We show that GltR is a transcriptional repressor that is released from DNA upon phosphorylation.
    Nucleic Acids Research 06/2014; · 8.81 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The nosocomial pathogen Pseudomonas aeruginosa is equipped with a large arsenal of cell- associated and secreted virulence factors, which enhance its invasive potential. The complex relationships among virulence determinants have hitherto not been fully elucidated. In the present study, 175 catheter-related isolates were observed for the presence of selected virulence factors, namely extracellular enzymes and siderophores production, biofilm formation, resistance to antibiotics, and motility. A high percentage of the strains produced most of the tested virulence factors. A positive correlation was identified between the production of several exoproducts, and also between the formation of both types of biofilm. An opposite trend was observed between the two types of biofilm and the production of siderophores. While the relationship between the submerged biofilm production (i.e. the biofilm formed on the solid surface below the water level) and the siderophores secretion was negative, the production of air-liquid interface biofilm (i.e. the biofilm floating on the surface of the cultivation medium) and the siderophores secretion correlated positively. All correlations were statistically significant at the level p=0.05 with the correlation coefficient γ≥0.50. Our results suggest that: (i) the co-production of the lytic enzymes and siderophores can play important role in the pathogenesis of the catheter-related infections and should be taken into account when the virulence potential is assessed; (ii) biofilm-positive strains are capable of forming both submerged and non-attached A-L biofilms; (iii) the different micro-environment in the submerged biofilm and A-L biofilm layers leads to opposite consequences for the production of other virulence factors. This article is protected by copyright. All rights reserved.
    Foodborne Pathogens and Disease 05/2014; · 2.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background C3 complement plays a pivotal role in the complement cascade, subserves several critical functions in human immune response and enhancing bacterial killing and its levels correlate with infectious diseases. However, the association of C3 with recurrent urinary tract infection (UTI) is still debatable. Aim The aim of this study was to assess the correlation of serum C3 levels and recurrent UTI among young women. Materials and methods Thirty-four recurrent UTI patients whose diagnosed based on Society of Obstetricians and Gynecologists of Canada and European Association of Urology criteria and 34 healthy young women, aged 15–50 years old, were included in this study. Risk factors and clinical manifestations were evaluated and serum C3 levels were measured by ELISA. Correlations of risk factors, clinical manifestation and C3 levels with recurrent UTI were analyzed with chi-square test and Fisher’s exact test or t-test as appropriate with data. Results This study found that some risk factors (age [p = 0.000], sexual intercourse frequency [p = 0.00], marital status [p = 0.000] and intrauterine device contraception [p = 0.000]) and clinical manifestations (fever [p = 0.000], dysuria [p = 0.000], frequent urination [p = 0.000], supra-pubic discomfort [p = 0.000] and flank pain [p = 0.006]) were correlated with recurrent UTI. Although this study found that serum C3 levels were significantly different between recurrent UTI patients and healthy young women group (mean 42.08 μg/ml ± 1.20 vs 42.75 μg/ml ± 0.71, p = 0.008), this difference is not clinically relevant. Conclusion In this study setting, the levels of C3 among young women with recurrent UTI were lower than healthy women but were not significant clinically.
    Alexandria Journal of Medicine. 05/2014;

Full-text (2 Sources)

Download
95 Downloads
Available from
May 29, 2014