Detection of virulence genes in Escherichia coli isolated from patients with cystitis and pyelonephritis.

Uropathogenic Escherichia coli (UPEC) is a common cause of ascending urinary tract infections including cystitis and pyelonephritis. The purpose of this study was to investigate virulence genes among Escherichia coli isolated from patients with cystitis and pyelonephritis. Between December 2012 and June 2013, 150 E. coli isolates from hospitalized patients with pyelonephritis (n = 72) and cystitis (n=78) were collected at Shahid Beheshti Hospital in Kashan. A PCR assay was used to evaluate the presence of virulence genes including pap, hly, aer, sfa, cnf, afa, traT, and pathogenicity island (PAI) markers in isolates. Of the total 150 UPEC isolates, 130 (86.7%) were found to carry the virulence genes studied. Nineteen different virulence patterns were identified. The most prevalent virulence pattern was UPEC including traT-PAI operons. The pap, traT, aer, hly, and PAI operons were more prevalent among patients with pyelonephritis than cystitis, and the sfa, afa, and cnf genes were not detected in any of the isolates. Higher virulence gene diversity was found among pyelonephritis UPEC isolates in comparison to cystitis UPEC isolates, showing that UPEC strains that cause pyelonephritis need more virulence factors.

Firoozeh F ，Saffari M ，Neamati F ，Zibaei M ... -  《-》

Distribution of uropathogenic virulence genes in Escherichia coli isolated from patients with urinary tract infection.

Escherichia coli is the predominant pathogen causing urinary tract infection (UTI), the most common bacterial infectious disease encountered in clinical practice, accounting for significant morbidity and high medical costs. The severity of UTI produced by E. coli is due to the expression of a wide spectrum of virulence factors. In this study we evaluated the role of E. coli virulence determinants in the pathogenesis of UTI. A total of 90 uropathogenic E. coli strains were screened by PCR for the prevalence of seven virulence genes encoding type 1 fimbriae (fimH), pili associated with pyelonephritis (pap), S and F1C fimbriae (sfa and foc), afimbrial adhesins (afa), cytotoxic necrotizing factor (cnf), hemolysin (hly), and aerobactin (aer). The prevalence of genes coding for fimbrial adhesive systems was 68% for fimH, 41% for pap, and 34% for sfa/foc. The operons coding for afa afimbrial adhesins were identified in 20% of strains. The hly and cnf genes coding for toxins were amplified in 19% and 3% of strains, respectively. A prevalence of 52% was found for the aer gene. The various combinations of detected genes were designated as virulence patterns. The strains isolated from hospitalized patients displayed a great diversity of gene associations compared to those isolated from ambulatory patients. Our study showed that investigation of the bacterial pathogenicity associated with UTI may contribute to a better medical intervention.

Tarchouna M ，Ferjani A ，Ben-Selma W ，Boukadida J ... -  《-》

Virulence factors and O groups of Escherichia coli isolates from patients with acute pyelonephritis, cystitis and asymptomatic bacteriuria.

Blanco M ，Blanco JE ，Alonso MP ，Blanco J ... -  《EUROPEAN JOURNAL OF EPIDEMIOLOGY》

Virulence factors and antimicrobial resistance in uropathogenic Escherichiacoli strains isolated from cystitis and pyelonephritis.

Ghazvini H ，Taheri K ，Edalati E ，Sedighi M ，Mirkalantari S ... -  《-》

Distribution of virulence genes and their association with antimicrobial resistance among uropathogenic Escherichia coli isolates from Iranian patients.

Malekzadegan Y ，Khashei R ，Sedigh Ebrahim-Saraie H ，Jahanabadi Z ... -  《BMC INFECTIOUS DISEASES》