Evaluation of pathogenicity islands in uropathogenic Escherichia coli isolated from patients with urinary catheters

Abstract

Introduction: Uropathogenic Escherichia coli (UPEC), an important causative agent of urinary tract infections (UTIs), carries virulence factors which are clustered on pathogenicity islands (PAIs) .The goal of this study was to characterize the PAIs among the UPEC isolated from patients with urinary catheters. Methodology: A descriptive cross-sectional study was designed and from December 2014 to April 2015, 78 non-duplicate E. coli were collected from hospitalized patients with UTIs, including patients with and without indwelling urinary catheters. Two multiplex polymerase chain reaction (PCR) assays were performed to evaluate the presence of the eight most studied PAIs (I 536 were not detected in the UPEC strains. Conclusions: The findings of this study revealed that the frequency of PAI markers in UPEC isolates from patients with indwelling urinary catheters was high. The rate of multiple PAIs carriage was notable among those patients, suggesting that UPEC strains that colonize the indwelling urinary catheters have the potential to cause complicated urinary infections. PAI ICFT073, which was found in association with pyelonephritis, prostatitis, and sepsis, could be considered as a target for medical interventions.

Characterization of E. coli Phylogroups Causing Catheter-Associated Urinary Tract Infection

“…PAIs are present in pathogenic E. coli strains carrying the virulence genes that encode the virulence determinants and are rarely found in non-pathogenic strains. Similar to our findings, Firoozeh et al 7 have detected 5 of 8 PAIs in 87.1% of the UPEC isolates where the PAI IV536 was the most prevalent marker. They found 42% of the UPEC isolates from CAUTI carried 2–3 PAI markers at the same time primarily PAI IV536 with no difference in the detected PAIs among CAUTI and Com-UTI strains.…”

“…Additionally, it is the first PAI acquired and most stable PAI on the chromosome. 7,10,21 In the current study, PAI I536, PAI II536 and PAI IIJ96 were not detected and PAI IJ96 and PAI III536 were detected at a low frequency in UPEC isolates which might be because of PAI II536 and PAI IJ96 is not important in the pathogenesis of UTI. Additionally, PAI II536 and PAI III536 are unstable and easy to lose.…”

“…Characterization of different phylogroups of uropathogenic E. coli is crucial to understand the pathogenesis of the infection and plan for treatment, prevention and control of UTI especially in hospitals. 7 , 22 …”

“…Characterization of different phylogroups of uropathogenic E. coli is crucial to understand the pathogenesis of the infection and plan for treatment, prevention and control of UTI especially in hospitals. 7,22 The present study involved UPEC strains isolated from 90 adult patients with CAUTI and Com-UTI. Antibiotic resistance pattern of UPEC strains showed a similar high resistance pattern in CAUTI and Com-UTI strains to ampicillin, amoxicillin-clavulanate, cefuroxime, tetracycline, ciprofloxacin, norfloxacin, trimethoprim-sulfamethoxazole, ceftazidime and aztreonam; 100%, 86.7%, 86.7%, 75.6%, 71.1%, 71.1%, 66.7%, 55.6% and 53.3% vs 100%, 73.3%, 84.4%, 75.6%, 66.7%, 60%, 62.2%, 46.7% and 46.7%, respectively, and a similar low resistance to amikacin, meropenem and gentamicin; 4.4%, 6.7% and 26.7% vs 2.2%, 4.4% and 20%, respectively.…”

“…These pathogenicity islands are mobile genetic elements and can horizontally transfer the virulence genes so they have an important role in the evolution of the bacteria. [5][6][7] Several virulence factors of UPEC strains are encoded on different PAIs including PAI I536, PAI II536, PAI III536, PAI IV536, PAI ICFT073, PAI IICFT073, PAI IJ96 and PAI IIJ96. These virulence determinants are needed to overcome the host immunity and include α-hemolysin which helps host's invasion, adhesins that attach UPEC to the epithelium of the urinary tract as P-fimbrial adhesins and S-fimbrial adhesins, the cytotoxic necrotizing factor which assists dissemination and persistence of infection in the urinary tract and the iron acquisition systems (aerobactin and yersiniabactin).…”