Phylogenetic background and carriage of pathogenicity island-like domains in relation to antibiotic resistance profiles among Escherichia coli urosepsis isolates.

We studied 100 well-characterized E. coli blood isolates from patients with urosepsis for their susceptibility to nalidixic acid, ampicillin and trimethoprim-sulfamethoxazole, according to prevalence of virulence factors, phylogenetic groups and subgroups, PAI II(J96)-like domains (determined by physical linkage of cnf1, hly and hra) and PAI I(CFT073)-like domains (determined by physical linkage of papGII to the hly locus). Nalidixic acid resistance was associated with a lower prevalence of sfa/foc, K1 antigen, pathogenicity island II(J96)-like domains, subgroup B2/I and a shift towards group A.