Abstract
Escherichia coli sequence type 131 (ST131), an emerging disseminated public health threat, causes multidrug-resistant extraintestinal infections. Among 579 diverse E. coli ST131 isolates from 1967-2009, we compared pulsotypes (>94% similar XbaI pulsed-field gel electrophoresis profiles) by collection year, geographic origin, source, and antimicrobial drug-resistance traits. Of 170 pulsotypes, 65 had >2 isolates and accounted for 85% of isolates. Although extensively dispersed geographically, pulsotypes were significantly source specific (e.g., had little commonality between humans vs. foods and food animals). The most prevalent pulsotypes were associated with recent isolation, humans, and antimicrobial drug resistance. Predominant pulsotype 968 was associated specifically with fluoroquinolone resistance but not with extended-spectrum β-lactamase production or bla(CTX-M-15). Thus, several highly successful antimicrobial drug-resistant lineages within E. coli ST131 have recently emerged and diffused extensively among locales while maintaining a comparatively restricted host/source range. Identification of factors contributing to this behavior of ST131 could help protect public health.
Highlights
The prevalence of resistance to fluoroquinolones and extended-spectrum cephalosporins in Escherichia coli has increased dramatically over the past decade
We analyzed 579 sequence type 131 (ST131) isolates from diverse sources according to a standardized pulsed-field gel electrophoresis (PFGE) protocol and compared PFGE profiles with other characteristics, including geographic origin, time of collection, ecologic source, and antimicrobial drug–resistance traits
Full multilocus sequence typing (MLST) was done de novo for 57 (10.5%) of these presumptive ST131 isolates, which represented diverse time periods, locales, sources, and resistance characteristics; in each instance, presumptive ST131 status was confirmed (SNP PCR specificity 100%; 95% CI 94%–100%)
Summary
The prevalence of resistance to fluoroquinolones and extended-spectrum cephalosporins in Escherichia coli has increased dramatically over the past decade. This increase is largely the result of the widespread emergence of a single disseminated E. coli clonal group, designated sequence type (ST) 131 according to multilocus sequence typing (MLST) (1,2). Unlike most other antimicrobial drug–resistant E. coli, ST131 derives from virulence-associated phylogenetic group B2 and typically exhibits multiple virulence factors, including adhesins, siderophores, toxins, and group 2 capsule (1–7). It thereby poses the dual threat of extensive antimicrobial drug resistance plus virulence. We analyzed 579 ST131 isolates from diverse sources according to a standardized PFGE protocol and compared PFGE profiles with other characteristics, including geographic origin, time of collection, ecologic source, and antimicrobial drug–resistance traits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
