To determine the prevalence of virulence factors and the antimicrobial susceptibilities of uropathogenic Escherichia coli isolates in Jiangsu province, China.

A total of 202 uropathogenic E. coli isolates were characterized for O serogroups, virulence factor genes, the antimicrobial susceptibilities, and the phylogenetic groups. The antibiotic-resistance phenotypes in relation to virulence factor genes were assessed by statistical analysis.

O1 was the most prevalent serogroup, and D and B2 were the most frequent phylogenetic groups. Of the 33 tested virulence genes, feoB and fimH were the most prevalent. Of the 15 antimicrobial agents tested, resistance to nalidixic acid, mezlocillin, ampicillin, and tetracycline was the most frequent. All isolates were multiresistant, and 73% were resistant to trimethoprim-sulfamethoxazole. Cefotaxime-, cefoxitin-, chloramphenicol-, and nitrofurantoin-resistant isolates had reduced virulence factor genes compared with susceptible strains.

In Jiangsu province, the problem of antibiotic resistance for uropathogenic E. coli is rather serious and empiric treatment of urinary tract infections with all the antibiotics we tested is no longer appropriate. Cefotaxime-, cefoxitin-, chloramphenicol-, and nitrofurantoin-resistant isolates have a reduced virulence factor genes compared with susceptible strains.