Differences in Virulence Factors among Clinical Isolates of Escherichia coli Causing Cystitis and Pyelonephritis in Women and Prostatitis in Men

Abstract

Differences in the presence of nine urovirulence factors among clinical isolates of Escherichia coli causing cystitis and pyelonephritis in women and prostatitis in men have been studied. Hemolysin and necrotizing factor type 1 occur significantly more frequently among isolates causing prostatitis than among those causing cystitis (P < 0.0001) or pyelonephritis (P < 0.005). Moreover, the papGIII gene occurred more frequently in E. coli isolates associated with prostatitis (27%) than in those associated with pyelonephritis (9%) (P < 0.05). Genes encoding aerobactin and PapC occurred significantly less frequently in isolates causing cystitis than in those causing prostatitis (P < 0.01 and P < 0.0001, respectively) and pyelonephritis (P < 0.01 and P < 0.0001, respectively). No differences in the presence of Sat or type 1 fimbriae were found. Finally, AAFII and Bfp fimbriae are no longer considered uropathogenic virulence factors since they were not found in any of the strains analyzed. Overall, the results showed that clinical isolates producing prostatitis need greater virulence than isolates producing pyelonephritis in women or, in particular, cystitis in women (P < 0.05). Overall, the results suggest that clinical isolates producing prostatitis are more virulent that those producing pyelonephritis or cystitis in women.Urinary tract infections (UTIs) are one of the most common infectious diseases encountered in the clinical practice, mainly being associated with different members of the family Enterobacteriaceae. In fact, Escherichia coli is by far the most predominant pathogen causing UTIs (4,18,19,21).In general, rates of UTIs are higher among women than among men (15), with cystitis being the most prevalent UTI in women. It is noteworthy that the prevalence of quinolone resistance among E. coli strains causing cystitis is significantly higher than the prevalence of quinolone resistance among strains causing urinary parenchymatous infections such as prostatitis and pyelonephritis (2, 23). Velasco et al. (23) found that 20% of the isolates causing cystitis were resistant to ciprofloxacin, while only 8% of the invasive isolates causing UTIs had a resistant phenotype. Some studies suggest that resistance to the quinolones may be associated with a diminished virulence of the uropathogenic strains (16). Moreover, in a recent work (25), the prevalence of different genes encoding certain virulence factors among quinolone-resistant E. coli isolates causing cystitis and pyelonephritis in women was found to be lower than that among quinolone-susceptible strains.Both host and bacterial factors have been associated with the pathogenesis of these infections (9, 21). Thus, uropathogenic strains of E. coli are believed to display a variety of virulence properties that help them colonize host mucosal surfaces and circumvent host defenses to allow invasion of the normally sterile urinary tract (15,18,21). A number of virulence determinants have been related to the acquisition or development of UTIs. Among these factors, sidero...

The Role of Host Factors and Bacterial Virulence Genes in the Development of Pyelonephritis Caused by Escherichia coli in Renal Transplant Recipients

“…Although there are several studies assessing E. coli virulence genes in upper UTI (5,(11)(12)(13), only one of them has been conducted in renal Tx recipients (21). We aimed to evaluate host and bacterial virulence factors mostly associated with PN by E. coli in Tx patients.…”

“…Although patients with neurogenic bladder were excluded from the sample presented here, UTI occurring in a transplanted patient is already considered as a complicated one (47) because of the heterotopic position of the graft and the shorter ureteral length. Finally, studies that observed a high prevalence of papGII in PN could have been biased by the exclusion of quinolone-resistant strains (5) because the latter would possibly possess fewer virulence factors (5,13).…”

“…PapG adhesins at the tip of P-fimbriae mediate specific binding to glycolipid receptors on the uroepithelia and renal tissue; three molecular variants of PapG have been identified (9,10). PapGII (11,12) and PapC (5,13) are suggested to be associated with upper UTI (PN), whereas PapGIII predominates in lower UTI (Cys) (14). In addition to adhesins, other virulence factors (i.e., aerobactin, hemolysin, and capsular polysaccharide) may be associated with the clinical manifestations of PN (12,13,15).…”

Pseudomonas aeruginosa las and rhl quorum-sensing systems are important for infection and inflammation in a rat prostatitis model

“…aeruginosa is damaging to prostate tissue may be due to its sizeable genome and large repertoire of virulence factors. Epidemiological evidence has shown that bacteria require a large collection of virulence factors to establish prostate infections as compared to other urological infections such as cystitis and pyelonephritis (Ruiz et al, 2002). Furthermore, prostatitis isolates tend to be better biofilm formers than either cystitis or pyelonephritis isolates (Kanamaru et al, 2006).…”

Análisis genético y propiedades virulentas de cepas de Escherichia coliaisladas desde infección vaginal

“…Estudios previos han demostrado que los genes del factor citotóxico necrosante y la toxina α-hemolisina, son portados en la misma isla de patogenicidad (IP) 36 . En este estudio se detectó que 56% de las cepas presenta esta asociación, pudiendo argumentarse que las cepas de E. coli causantes de infecciones vaginales poseen algunas características de cepas necro-toxigénicas.…”