title: Genetic background of Escherichia coli and extended-spectrum beta-lactamase type.
abstract: To assess the implication of the genetic background of Escherichia coli strains in the emergence of extended-spectrum-Beta -lactamases (ESBL), 55 TEM-, 52 CTX-M-, and 22 SHV-type ESBL-producing clinical isolates involved in various extraintestinal infections or colonization were studied in terms of phylogenetic group, virulence factor (VF) content (pap, sfa/foc, hly, and aer genes), and fluoroquinolone resistance. A factorial analysis of correspondence showed that SHV type, and to a lesser extent TEM type, were preferentially observed in B2 phylogenetic group strains that exhibited numerous VFs but were fluoroquinolone-susceptible, whereas the newly emerged CTX-M type was associated with the D phylogenetic group strains that lacked VF but were fluoroquinolone-resistant. Thus, the emergence of ESBL-producing E. coli seems to be the result of complex interactions between the type of ESBL, genetic background of the strain, and selective pressures in ecologic niches.
authors.affiliation: Laboratoire de Microbiologie, Hôpital Louis Mourier, AP-HP, 178 Rue des Renouillers, 92701 Colombes Cedex, France. catherine.branger@lmr.ap-hop-paris.fr
authors.forename: Catherine
authors.initials: C
authors.lastname: Branger
authors.forename: Oana
authors.initials: O
authors.lastname: Zamfir
authors.forename: Sabine
authors.initials: S
authors.lastname: Geoffroy
authors.forename: Geneviève
authors.initials: G
authors.lastname: Laurans
authors.forename: Guillaume
authors.initials: G
authors.lastname: Arlet
authors.forename: Hoang Vu
authors.initials: HV
authors.lastname: Thien
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Gouriou
authors.forename: Bertrand
authors.initials: B
authors.lastname: Picard
authors.forename: Erick
authors.initials: E
authors.lastname: Denamur
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D021821:Communicable Diseases, Emerging / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D024841:Fluoroquinolones / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism; D001618:beta-Lactamases / Q000145:classification* / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D024841:Fluoroquinolones; D037521:Virulence Factors; D002939:Ciprofloxacin; D001618:beta-Lactamases