Association of virulent genes hly, sfa, cnf-1 and pap with antibiotic sensitivity in Escherichia coli strains isolated from children with community-acquired UTI

ABSTRACT

Recent studies have suggested that the decrease in the pathogenicity of E. coli is due to acquisition of resistance to some antibiotics. This study was performed to investigate four virulence factors of pap, cnf-1, sfa and hly in resistant E. coli and compare them with susceptible strains of the bacteria isolated from children with community-acquired UTI. Drug sensitivity of 96 E. coli isolates was evaluated using a disc diffusion method. The prevalence of virulence genes was determined by PCR. E. coli strains showed a high degree of sensitivity to imipenem, amikacin, nitrofurantoin and ciprofloxacin. Approximately, 80.2% of the isolates were resistant to ampicilin. Only 12.5% of the strains were susceptible to all tested antibiotics. PCR showed that cnf-1 [22.9%] was more prevalent than hly [15.6%] and among adhesion coding genes, pap [30.2%] was more prevalent than sfa [18.8%]. In all strains, the expression of all virulent genes was less prevalent in most antibiotic resistant groups than in susceptible ones but not statistically significant except for genotypes of pap[+]-cnf[+], pap[+]- hIy[+] and cnf[+]-hly[+] with nalidixic acid. We propose that pap and cnf-1 genes in combination with hly gene constitute an uropathogenic genomic configuration which is the characteristic of the nalidixic-acid susceptible E. coli strains, causing urinary tract infection