Virulence Genes and Antibiotic Susceptibilities of Uropathogenic E. coli Strains

Background: The aim of this study is to detect the presence of and possible relation between virulence genes and antibiotic resistance in E. coli strains isolated from patients with acute, uncomplicated urinary tract infections (UTI). Methods: 62 E. coli strains isolated from patients with acute, uncomplicated urinary tract infections (50 strains isolated from acute uncomplicated cystitis cases (AUC); 12 strains from acute uncomplicated pyelonephritis cases (AUP)) were screened for virulence genes [pap (pyelonephritis-associated pill), sfalfoc (S and F1C fimbriae), afa (afimbrial adhesins), hly (hemolysin), cnfl (cytotoxic necrotizing factor), aer (aerobactin), PAI (pathogenicity island marker), iroN (catecholate siderophore receptor), ompT (outer membrane protein T), usp (uropathogenic specific protein)] by PCR and for antimicrobial resistance by disk diffusion method according to CLSI criteria. Results: It was found that 56 strains (90.3%) carried at least one virulence gene. The most common virulence genes were ompT (79%), aer (51.6%), PAI (51.6%) and usp (56.5%). 60% of the strains were resistant to at least one antibiotic. The highest resistance rates were against ampicillin (79%) and co-trimoxazole (41.9%). Fifty percent of the E. coli strains (31 strains) were found to be multiple resistant. Eight (12.9%) out of 62 strains were found to be ESBL positive. Statistically significant relationships were found between the absence of usp and AMP - SXT resistance, iroN and OFX - CIP resistance, PAI and SXT resistance, cnfl and AMP resistance, and a significant relationship was also found between the presence of the afa and OFX resistance. Conclusions: No difference between E. coli strains isolated from two different clinical presentations was found in terms of virulence genes and antibiotic susceptibility.