title: Emergence of clonal complex 17 Enterococcus faecium in The Netherlands.
abstract: The global emergence of vancomycin-resistant Enterococcus faecium has been characterized as the clonal spread of clonal complex 17 (CC17) E. faecium. CC17 was defined upon multilocus sequence typing and is characterized by resistance to quinolones and ampicillin and the presence of the enterococcal surface protein (Esp) in the majority of isolates. The recently noticed increased incidence of vancomycin-susceptible CC17 E. faecium infections in our hospital initiated a nationwide study to determine ecological changes among enterococcal infections. The data and strain collections were obtained from 26 (38%) and 9 (14%) of 66 microbiology laboratories in The Netherlands. E. faecium and E. faecalis were distinguished by multiplex PCR; all E. faecium isolates were genotyped by multiple-locus variable-number tandem-repeat analysis (MLVA), and the presence of esp was identified by PCR. Average numbers of ampicillin-resistant enterococcal isolates from normally sterile body sites per hospital increased from 5 +/- 1 in 1994 to 25 +/- 21 in 2005. Among all enterococcal bloodstream infections, the proportions of ampicillin-resistant E. faecium (AREF) increased from 4% in 1994 to 20% in 2005 (P < 0.001). All E. faecalis isolates were susceptible to ampicillin, whereas 78% of the E. faecium isolates were resistant (49% of these contained esp). Genotyping revealed that 86% of AREF isolates belonged to CC17, including four dominant MLVA types found in > or = 3 hospitals, accounting for 64% of the AREF isolates. Infections caused by CC17 E. faecium has increased nationwide, especially in university hospitals due to the clonal spread of four MLVA types, and seems associated with acquisition of the esp gene.
authors.affiliation: Department of Medical Microbiology, University Medical Center Utrecht, G04.614, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. j.top@umcutrecht.nl
authors.forename: Janetta
authors.initials: J
authors.lastname: Top
authors.forename: Rob
authors.initials: R
authors.lastname: Willems
authors.forename: Saskia
authors.initials: S
authors.lastname: van der Velden
authors.forename: Miranda
authors.initials: M
authors.lastname: Asbroek
authors.forename: Marc
authors.initials: M
authors.lastname: Bonten
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D013293:Enterococcus faecalis / Q000235:genetics / Q000302:isolation & purification; D016984:Enterococcus faecium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics; D018598:Minisatellite Repeats; D009426:Netherlands / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000379:methods; D015363:Quinolones / Q000494:pharmacology; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; D015363:Quinolones; C116707:enterococcal surface protein, esp; D000667:Ampicillin