Dissemination of clonally related Escherichia coli strains expressing extended-spectrum beta-lactamase CTX-M-15

Emerg Infect Dis. 2008 Feb;14(2):195-200. doi: 10.3201/eid1402.070350.


We analyzed 43 CTX-M-15-producing Escherichia coli isolates and 6 plasmids encoding the blaCTX-M-15 gene from Canada, India, Kuwait, France, Switzerland, Portugal, and Spain. Most isolates belonged to phylogroups B2 (50%) and D (25%). An EC-B2 strain of clonal complex sequence type (ST) 131 was detected in all countries; other B2 isolates corresponded to ST28, ST405, ST354, and ST695 from specific areas. EC-D strains were clonally unrelated but isolates from 3 countries belonged to ST405. All CTX-M-15 plasmids corresponded to IncFII group with overrepresentation of 3 HpaI-digested plasmid DNA profiles (A, B and C; 85-120kb, similarity > or =70%). Plasmid A was detected in EC-B2 strains (ST131, ST354, or ST405), plasmid C was detected in B2 and D strains, and plasmid B was confined to worldwide-disseminated ST131. Most plasmids contained blaOXA-1, aac(6')-Ib-cr, and blaTEM-1. Worldwide dissemination of CTX-M-15 seems to be determined by clonal complexes ST131 and ST405 and multidrug-resistant IncFII plasmids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Canada / epidemiology
  • Drug Resistance, Multiple, Bacterial / genetics
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics*
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / epidemiology
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / transmission*
  • Escherichia coli Proteins / genetics
  • Europe / epidemiology
  • Humans
  • India / epidemiology
  • Kuwait / epidemiology
  • Plasmids / genetics*
  • beta-Lactam Resistance / genetics
  • beta-Lactamases / biosynthesis*
  • beta-Lactamases / genetics


  • Escherichia coli Proteins
  • beta-lactamase CTX-M-15
  • beta-Lactamases