Acquisition of a pathogenicity island in an Escherichia coli clinical isolate causing febrile urinary tract infection.

Urinary tract infections (UTI) are less common in men than in women, and uropathogenic Escherichia coli (UPEC) is the most frequent etiological agent. Recurrent UTI in men have often been reported as a relapse with the same strain as the index infection. The persistence of the same E. coli strain within the urinary tract has often been explained by a prostatic focus. The aim of this study was to determine whether recurrence was associated with relapse or reinfection and the possible effect of treatment on the content of virulence factors of the isolates causing these infections. Thirty E. coli isolates were collected from 15 patients with a febrile UTI having a bacteriological recurrence during long-term follow-up. These isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and virulence profiling in order to determine whether they constituted relapse or reinfection. Five recurrences were categorized as relapse and nine as reinfections. The results obtained showed that the horizontal transfer of virulence factors contained in a pathogenicity island had occurred in one isolate. This event is possible in vivo and allows bacteria to become more virulent and, perhaps, cause greater damage. The acquisition of virulence genes by horizontal gene transfer is an ongoing process of evolution that continuously leads to new bacterial pathotypes.

Selective urological evaluation in men with febrile urinary tract infection.

OBJECTIVE: To investigate the prevalence and clinical importance of urological abnormalities in men with community-acquired febrile urinary tract infection (UTI). PATIENTS AND METHODS: In this prospective study, 85 men (median age 63 years, range 18--86) were followed for 1 year after an episode of febrile UTI. They were investigated by excretory urography, cysto-urethroscopy, uroflowmetry, digital rectal examination and measurement of postvoid residual urine volume by abdominal ultrasonography. RESULTS: The radiological examination of the upper urinary tract in 83 patients revealed 22 abnormal findings in 19 men. Relevant clinical abnormalities leading to surgical intervention were found in only one patient who had renal calyceal stones. The lower urinary tract investigation disclosed 46 findings in 35 men. In all, surgically correctable disorders were found in 20 patients, of whom 15 had previously unrecognized abnormalities. All patients who required surgery were identified either by a history of voiding difficulties, acute urinary retention at the time of infection, the presence of microscopic haematuria at follow-up after one month, or early recurrent symptomatic UTI. CONCLUSION: Routine imaging studies of the upper urinary tract seem dispensable in men with febrile UTI. To reveal abnormalities of clinical importance, any urological evaluation should primarily be focused on the lower urinary tract.

Prostatic involvement in men with febrile urinary tract infection as measured by serum prostate-specific antigen and transrectal ultrasonography.

OBJECTIVE: To determine the frequency of prostatic involvement in men with community-acquired febrile urinary tract infection. PATIENTS AND METHODS: This prospective study included 70 men (18-85 years old) who had a fever of >/=38.0 degrees C, symptoms or signs of urinary tract infection and a positive urine culture. Serum prostate-specific antigen (PSA) was measured and transrectal ultrasonography of the prostate and seminal vesicles performed during the acute phase of the disease and during a 1-year follow-up. RESULTS: Although only six patients had a tender prostate on digital rectal examination, the initial serum PSA level was elevated in 58 (83%) patients (median 14 ng/mL, range 0.54-140). There was no correlation between PSA levels, patient age, inflammatory response to infection or presence of positive blood cultures. Despite a rapid decline in PSA level after one month, there was a protracted decrease in some patients. After 3 months the median prostate volume was reduced by 31% (range 11-54; P<0.001) in 46 of 55 patients examined, and the width of the right and left seminal vesicle was reduced by 14% and 22%, respectively. The reductions in PSA and prostate volume were significantly correlated (r=0.36, 95% confidence interval 0.09-0.58; P=0.01). CONCLUSION: These results show that the prostate and seminal vesicles are frequently involved in men with febrile urinary tract infection and that PSA may be a useful marker of prostatic infection. The slow decline of PSA levels in some patients after appropriate antibiotic treatment indicates a protracted healing process and should be considered when PSA is used to detect prostate cancer.

Virulence characteristics of Escherichia coli in relation to host response in men with symptomatic urinary tract infection.

To assess virulence properties in uropathogenic Escherichia coli isolates from men with symptomatic urinary tract infection (UTI), we analyzed 88 urinary isolates from men with acute pyelonephritis (n = 41), febrile UTI without clinical signs of renal infection (n = 33), or acute cystitis (n = 14) for O:K:H serotype, P fimbriae, and production of hemolysin and aerobactin. In the three diagnostic groups, 88%, 67%, and 79% of the strains, respectively, were represented by 10 O antigen groups commonly associated with acute pyelonephritis in women and children. Fifty-eight different O:K:H serotypes could be identified, of which O18ac:K5:H- predominated (n = 8). There was a higher frequency of hemolytic strains among patients with pyelonephritis (73%) and febrile UTI (76%) and a lower frequency of P-fimbriated strains (56% and 45%, respectively) and aerobactin-positive strains (51% and 39%, respectively) among these patients than was previously encountered in women and children with uncomplicated acute pyelonephritis. The distribution of bacterial properties was unrelated to patient age and underlying complicating factors. The findings suggest differences in host-parasite relationships between men and women with symptomatic UTI caused by E. coli.

Virulence factors and pap genotype in Escherichia coli isolates from women with acute pyelonephritis, with or without bacteremia.

Bacteremia develops in a subgroup of patients with acute pyelonephritis. This study examined isolates of Escherichia coli from the urine and the blood of 25 bacteremic and 67 nonbacteremic women with this acute disease. P-fimbriated strains were found in 100% of bacteremic patients without complicating factors but in only 71% of nonbacteremic patients without complications (P < .05). Non-P-fimbriated strains were only found to cause bacteremia in three patients with compromising host factors. Strains from the bacteremic group and those from the nonbacteremic group did not differ significantly in terms of hemolysin or aerobactin production or of serum resistance. The P-fimbriated strains from both groups of patients carried pap DNA sequences of the papGIA2 adhesin type; prsGJ96 homologous DNA sequences were rare. The results suggested that P fimbriae and compromising host conditions independently increase the risk for bacteremia during acute pyelonephritis.