Lower prevalence of hlyD, papC and cnf-1 genes in ciprofloxacin-resistant uropathogenic Escherichia coli than their susceptible counterparts isolated from southern India

SummaryObjectiveThe study was conducted to determine the association of the hlyD, papC and cnf-1 virulence genes with drug resistance in uropathogenic Escherichia coli (UPEC) isolated from cases of urinary tract infection (UTI).MethodA total of 193 E. coli strains isolated from symptomatic cases of UTI in a tertiary care teaching hospital in Raichur, Northern Karnataka, India were included in the study. The antibiotic susceptibility pattern was determined by Kirby–Bauer's Disk Diffusion method, and the strains resistant to any of the third generation cephalosporins tested were further confirmed for extended-spectrum beta-lactamase (ESBL)-production by an E-strip test. Genotypic virulence markers, namely, hlyD, papC and cnf-1, were detected by the uniplex PCR method and the phylogenetic characterization was performed by a multiplex PCR assay.ResultsThe majority of the E. coli isolates belonged to the B2 phylogenetic group were significantly associated with ciprofloxacin-sensitivity and non-ESBL production (p < 0.05). An increased prevalence of ciprofloxacin-sensitive strains over ciprofloxacin-resistant strains were observed among the UPEC isolates harboring the papC (72.9% vs. 40.2%; p < 0.001), hlyD (43.7% vs. 21.6%; p < 0.001) and cnf-1 (30.2% vs. 12.3%; p < 0.05) genes. The presence of a multivirulent gene in the non-ESBL E. coli strains (44.5%) was significantly higher (p < 0.05) than in the ESBL-producing strains (21%).ConclusionsAmong the UPEC isolates, the predominant B2 phylogenetic group was significantly associated with the ciprofloxacin-sensitive strains, as well as with the non-ESBL E. coli strains. The genotypic virulence markers of UPEC were associated with ciprofloxacin-sensitivity, and a significant number of the non-ESBL strains harbored multivirulent genes. The relationship between the presence of the virulence genes and ESBL production was complex and warrants further intensive studies.