Major uropathogenic Escherichia coli strain isolated in the northwest of England identified by multilocus sequence typing

Abstract

A total of 88 uropathogenic Escherichia coli isolates, including 68 isolates from urine and 20 isolates from blood, were characterized by multilocus sequence typing (MLST). MLST has identified an important genetic lineage of E. coli, designated sequence type 131 (ST-131), represented by 52 of these isolates, 51 of which were resistant to extended-spectrum cephalosporins. ST-131 appears to be a drug-resistant uropathogenic strain of E. coli responsible for causing urinary tract infections and bacteremia and is widely disseminated among both community and hospital patients from different geographical areas in the northwest of England. Application of MLST has helped to define the population biology which may underpin the epidemiology of pathogenic E. coli strains. The portability of MLST allows the accurate monitoring of this antibiotic-resistant uropathogenic strain of E. coli and will enhance surveillance for this important group of organisms.

FIG. 1.

Population snapshots of E. coli clusters of related STs and individual unrelated STs within the entire E. coli MLST database. STs in circles are those identified in this study. This diagram does not show the genetic distance between unrelated STs and clonal complexes. The primary founder of each clonal complex is at a central position in the diagram. Two STs separated by one node represent a single-locus variation between two isolates (a single-locus variant). UPEC, uropathogenic E. coli.