scholarly journals Role of UropathogenicEscherichia coliVirulence Factors in Development of Urinary Tract Infection and Kidney Damage

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Justyna Bien ◽  
Olga Sokolova ◽  
Przemyslaw Bozko

UropathogenicEscherichia coli(UPEC) is a causative agent in the vast majority of urinary tract infections (UTIs), including cystitis and pyelonephritis, and infectious complications, which may result in acute renal failure in healthy individuals as well as in renal transplant patients. UPEC expresses a multitude of virulence factors to break the inertia of the mucosal barrier. In response to the breach by UPEC into the normally sterile urinary tract, host inflammatory responses are triggered leading to cytokine production, neutrophil influx, and the exfoliation of infected bladder epithelial cells. Several signaling pathways activated during UPEC infection, including the pathways known to activate the innate immune response, interact with calcium-dependent signaling pathways. Some UPEC isolates, however, might possess strategies to delay or suppress the activation of components of the innate host response in the urinary tract. Studies published in the recent past provide new information regarding how virulence factors of uropathogenicE. coliare involved in activation of the innate host response. Despite numerous host defense mechanisms, UPEC can persist within the urinary tract and may serve as a reservoir for recurrent infections and serious complications. Presentation of the molecular details of these events is essential for development of successful strategies for prevention of human UTIs and urological complications associated with UTIs.

2018 ◽  
Vol 35 (1-2) ◽  
pp. 28-31
Author(s):  
José Pedro Cadilhe

Introduction: Transrectal ultrasound guided prostate biopsy (TRUS-Bx), according to the literature, can lead to urinary tract infections in up to 11% and sepsis in up to 2% of patients. We evaluate whether an original way to apply povidone-iodine rectal preparation just prior to TRUS-Bx can reduce infectious complications. Material and Methods: Between January 2014 and September 2016, 94 men in private office were prospectively randomized to two groups, before TRUS-Bx: • Rectal cleansing (an original transrectal “prostate massage” for about half a minute with 2.5 mL of betadine dermic solution 100 mg/mL) (n=47) or • No cleansing (n=47). All of the patients received prophylactic antibiotics: levofloxacin 500 mg PO for 7 days, beginning the day before procedure. Patients completed a telephone interview 4 days after undergoing the biopsy and went to the office 2 weeks after biopsy. The primary end point was the rate of infectious complications. An infectious complication when one or more of the following events occurred: 1) fever greater than 38.0Cº, 2) urinary tract infection or 3) sepsis (standardized definition). Student t test and multivariate regression analysis were used for data analysis. Results: Infectious complications developed in 6 cases (12.7%) in the non-rectal preparation group: five patients had fever without sepsis (11%) and one had sepsis (2%). In the povidone-iodine rectal preparation group there were no infectious complications (0.0%). Multivariate analysis did not identify any patient subgroups at significantly higher risk of infection after prostate biopsy. Of the 94 men who underwent TRUS-Bx 45 (47.9%) were diagnosed with prostate cancer and 3 (3.2%) had ASAP in the result. The hospital admission rate for urological complications within 30 days of the procedure was 1%, and only for infection related reasons (sepsis). Conclusion: The administration of quinolone-based prophylactic antibiotics and the simple use of 2.5 mL of povidone-iodine dermic solution in a transrectal prostate massage for Introduction: Transrectal ultrasound guided prostate biopsy (TRUS-Bx), according to the literature, can lead to urinary tract infections in up to 11% and sepsis in up to 2% of patients. We evaluate whether an original way to apply povidone-iodine rectal preparation just prior to TRUS-Bx can reduce infectious complications. Material and Methods: Between January 2014 and September 2016, 94 men in private office were prospectively randomized to two groups, before TRUS-Bx: • Rectal cleansing (an original transrectal “prostate massage” for about half a minute with 2.5 mL of betadine dermic solution 100 mg/mL) (n=47) or • No cleansing (n=47). All of the patients received prophylactic antibiotics: levofloxacin 500 mg PO for 7 days, beginning the day before procedure. Patients completed a telephone interview 4 days after undergoing the biopsy and went to the office 2 weeks after biopsy. The primary end point was the rate of infectious complications. An infectious complication when one or more of the following events occurred: 1) fever greater than 38.0Cº, 2) urinary tract infection or 3) sepsis (standardized definition). Student t test and multivariate regression analysis were used for data analysis. Results: Infectious complications developed in 6 cases (12.7%) in the non-rectal preparation group: five patients had fever without sepsis (11%) and one had sepsis (2%). In the povidone-iodine rectal preparation group there were no infectious complications (0.0%). Multivariate analysis did not identify any patient subgroups at significantly higher risk of infection after prostate biopsy. Of the 94 men who underwent TRUS-Bx 45 (47.9%) were diagnosed with prostate cancer and 3 (3.2%) had ASAP in the result. The hospital admission rate for urological complications within 30 days of the procedure was 1%, and only for infection related reasons (sepsis). Conclusion: The administration of quinolone-based prophylactic antibiotics and the simple use of 2.5 mL of povidone-iodine dermic solution in a transrectal prostate massage for


2017 ◽  
Vol 68 (3) ◽  
pp. 566-569 ◽  
Author(s):  
Mihaela Magdalena Mitache ◽  
Carmen Curutiu ◽  
Elena Rusu ◽  
Ramona Bahna ◽  
Mara Ditu ◽  
...  

One of the most frequent chronic complications occurred in diabetes patients are the urinary tract infections (UTIs). This study aimed to investigate the incidence of UTIs in a cohort of 93 (47 males: 46 females) diabetic patients, the prevalence of different microbial species involved and their virulence and antibiotic resistance profiles. The identification of the uropathogenic strains in the positive urine samples was performed using conventional methods and API tests. After identification, the antibiotic susceptibility profiles were established by the standardized disk diffusion method and double disk diffusion test was performed for the confirmation of ESBL and inducible AmpC b �lactamase phenotypes. The isolated strains were tested for the production of different cell associated and soluble virulence factors, i.e.: bacterial adherence to cellular substrata (HeLa cells), hemolysins (hemolysis spot, CAMP-like), amylase, caseinase, aesculin hydrolysis, DNA-ase, lipase and lecithinase. In the analyzed group, the total prevalence of UTIs was of 46%, a higher incidence being observed in the female patients (64%). Similar to other studies, the etiology of UTI in the investigated diabetes patients was dominated by E. coli, followed by Klebsiella sp. strains. The isolated strains preserved good susceptibility rates to quinolones and aminoglycosides and revealed important virulence features, related to their capacity to colonize the cellular substratum and to produce soluble virulence factors involved in persistence, colonization and progression of the infectious process. The high percentage of beta-lactam resistant strains (including carbapenem-resistant ones) requires careful surveillance of the dynamics of susceptibility profiles for limiting the emergence of these strains in community.


2014 ◽  
Vol 83 (3) ◽  
pp. 966-977 ◽  
Author(s):  
Ming-Che Liu ◽  
Kuan-Ting Kuo ◽  
Hsiung-Fei Chien ◽  
Yi-Lin Tsai ◽  
Shwu-Jen Liaw

Proteus mirabilisis a common human pathogen causing recurrent or persistent urinary tract infections (UTIs). The underlying mechanisms forP. mirabilisto establish UTIs are not fully elucidated. In this study, we showed that loss of the sigma factor E (RpoE), mediating extracytoplasmic stress responses, decreased fimbria expression, survival in macrophages, cell invasion, and colonization in mice but increased the interleukin-8 (IL-8) expression of urothelial cells and swarming motility. This is the first study to demonstrate that RpoE modulated expression of MR/P fimbriae by regulatingmrpI, a gene encoding a recombinase controlling the orientation of MR/P fimbria promoter. By real-time reverse transcription-PCR, we found that the IL-8 mRNA amount of urothelial cells was induced significantly by lipopolysaccharides extracted fromrpoEmutant but not from the wild type. These RpoE-associated virulence factors should be coordinately expressed to enhance the fitness ofP. mirabilisin the host, including the avoidance of immune attacks. Accordingly,rpoEmutant-infected mice displayed more immune cell infiltration in bladders and kidneys during early stages of infection, and therpoEmutant had a dramatically impaired ability of colonization. Moreover, it is noteworthy that urea (the major component in urine) and polymyxin B (a cationic antimicrobial peptide) can induce expression ofrpoEby the reporter assay, suggesting that RpoE might be activated in the urinary tract. Altogether, our results indicate that RpoE is important in sensing environmental cues of the urinary tract and subsequently triggering the expression of virulence factors, which are associated with the fitness ofP. mirabilis, to build up a UTI.


2011 ◽  
Vol 80 (2) ◽  
pp. 493-505 ◽  
Author(s):  
Patrick D. Vigil ◽  
Travis J. Wiles ◽  
Michael D. Engstrom ◽  
Lev Prasov ◽  
Matthew A. Mulvey ◽  
...  

ABSTRACTUropathogenicEscherichia coli(UPEC) is responsible for the majority of uncomplicated urinary tract infections (UTI) and represents the most common bacterial infection in adults. UPEC utilizes a wide range of virulence factors to colonize the host, including the novel repeat-in-toxin (RTX) protein TosA, which is specifically expressed in the host urinary tract and contributes significantly to the virulence and survival of UPEC.tosA, found in strains within the B2 phylogenetic subgroup ofE. coli, serves as a marker for strains that also contain a large number of well-characterized UPEC virulence factors. The presence oftosAin anE. coliisolate predicts successful colonization of the murine model of ascending UTI, regardless of the source of the isolate. Here, a detailed analysis of the function oftosArevealed that this gene is transcriptionally linked to genes encoding a conserved type 1 secretion system similar to other RTX family members. TosA localized to the cell surface and was found to mediate (i) adherence to host cells derived from the upper urinary tract and (ii) survival in disseminated infections and (iii) to enhance lethality during sepsis (as assessed in two different animal models of infection). An experimental vaccine, using purified TosA, protected vaccinated animals against urosepsis. From this work, it was concluded that TosA belongs to a novel group of RTX proteins that mediate adherence and host damage during UTI and urosepsis and could be a novel target for the development of therapeutics to treat ascending UTIs.


2013 ◽  
Vol 57 (9) ◽  
pp. 4512-4517 ◽  
Author(s):  
Etienne Ruppé ◽  
Brandusa Lixandru ◽  
Radu Cojocaru ◽  
Çağrı Büke ◽  
Elisabeth Paramythiotou ◽  
...  

ABSTRACTExtended-spectrum-beta-lactamase (ESBL)-producingEscherichia coli(ESBLE. coli) strains are of major concern because few antibiotics remain active against these bacteria. We investigated the association between the fecal relative abundance (RA) of ESBL-producingE. coli(ESBL-RA) and the occurrence of ESBLE. coliurinary tract infections (UTIs). The first stool samples passed after suspicion of UTI from 310 women with subsequently confirmedE. coliUTIs were sampled and tested for ESBL-RA by culture on selective agar. Predictive values of ESBL-RA for ESBLE. coliUTI were analyzed for women who were not exposed to antibiotics when the stool was passed. ESBLE. coliisolates were characterized for ESBL type, phylogroup, relatedness, and virulence factors. The prevalence of ESBLE. colifecal carriage was 20.3%, with ESBLE. coliUTIs being present in 12.3% of the women. The mean ESBL-RA (95% confidence interval [CI]) was 13-fold higher in women exposed to antibiotics at the time of sampling than in those not exposed (14.3% [range, 5.6% to 36.9%] versus 1.1% [range, 0.32% to 3.6%], respectively;P< 0.001) and 18-fold higher in women with ESBLE. coliUTI than in those with anotherE. coliUTI (10.0% [range, 0.54% to 100%] versus 0.56% [range, 0.15% to 2.1%[, respectively;P< 0.05). An ESBL-RA of <0.1% was 100% predictive of a non-ESBLE. coliUTI. ESBL type, phylogroup, relatedness, and virulence factors were not found to be associated with ESBL-RA. In conclusion, ESBL-RA was linked to the occurrence of ESBLE. coliUTI in women who were not exposed to antibiotics and who had the same clone ofE. coliin urine samples and fecal samples. Especially, a low ESBL-RA appeared to be associated with a low risk of ESBLE. coliinfection.


2014 ◽  
Vol 82 (9) ◽  
pp. 3644-3656 ◽  
Author(s):  
Michael D. Engstrom ◽  
Christopher J. Alteri ◽  
Harry L. T. Mobley

ABSTRACTA heterogeneous subset of extraintestinal pathogenicEscherichia coli(ExPEC) strains, referred to as uropathogenicE. coli(UPEC), causes most uncomplicated urinary tract infections. However, no core set of virulence factors exists among UPEC strains. Instead, the focus of the analysis of urovirulence has shifted to studying broad classes of virulence factors and the interactions between them. For example, the RTX nonfimbrial adhesin TosA mediates adherence to host cells derived from the upper urinary tract. The associatedtosoperon is well expressedin vivobut poorly expressedin vitroand encodes TosCBD, a predicted type 1 secretion system. TosR and TosEF are PapB and LuxR family transcription factors, respectively; however, no role has been assigned to these potential regulators. Thus, the focus of this study was to determine how TosR and TosEF regulatetosAand affect the reciprocal expression of adhesins and flagella. Among a collection of sequenced UPEC strains, 32% (101/317) were found to encode TosA, and nearly all strains (91% [92/101]) simultaneously carried the putative regulatory genes. Deletion oftosRalleviatestosArepression. Thetospromoter was localized upstream oftosRusing transcriptional fusions of putative promoter regions withlacZ. TosR binds to this region, affecting a gel shift. A 100-bp fragment 220 to 319 bp upstream oftosRinhibits binding, suggesting localization of the TosR binding site. TosEF, on the other hand, downmodulate motility when overexpressed by preventing the expression offliC, encoding flagellin. Deletion oftosEFincreased motility. Thus, we present an additional example of the reciprocal control of adherence and motility.


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