Molecular epidemiology of vancomycin-resistant Enterococcus faecium in Argentina.
OBJECTIVE
To characterize the mechanism of glycopeptide resistance and to determine the genetic relatedness among strains by pulsed-field gel electrophoresis (PFGE) in vancomycin-resistant Enterococcus faecium from Argentina.


METHODS
A total of 189 vancomycin-resistant single-patient isolates of Enterococcus faecium recovered between January 1997 and December 2000 from 30 hospitals in Argentina were studied. Minimum inhibitory concentrations were determined by the agar dilution method and van genes were detected by PCR. PFGE was used for molecular typing.


RESULTS
All isolates except three (vanB) were of genotype vanA. For 189 vancomycin-resistant Enterococcus faecium, SmaI-PFGE indicated 35 clonal types. Most of the isolates (56%) belonged to the same clonal type 1, which was present in 19 hospitals and dominant in 17.


CONCLUSIONS
The emergence of vancomycin-resistant Enterococcus faecium in Argentina seems to be related to the intra- and inter-hospital dissemination of an epidemic clone carrying the vanA element.
Corso
Alejandra C
AC
Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas - ANLIS Dr. Carlos G. Malbrán, Av. Velez Sarsfield 563 (1281), Buenos Aires, Argentina. acorso@anlis.gov.ar
Gagetti
Paula S
PS
Rodríguez
Marisa M
MM
Melano
Roberto G
RG
Ceriana
Paola G
PG
Faccone
Diego F
DF
Galas
Marcelo F
MF
D001118:Argentina / Q000453:epidemiology; D001426:Bacterial Proteins / Q000235:genetics; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D020713:Vancomycin Resistance / Q000235:genetics*
D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; D019729:Carbon-Oxygen Ligases