Multidrug-resistant Iberian epidemic clone of methicillin-resistant Staphylococcus aureus endemic in a hospital in northern Portugal

Microb Drug Resist. Winter 1995;1(4):299-306. doi: 10.1089/mdr.1995.1.299.


Forty-two methicillin-resistant Staphylococcus aureus (MRSA) isolates collected during 1992-1995 at a hospital in the north of Portugal were characterized by a variety of genomic fingerprints. Hybridization of ClaI and SmaI restriction digests with the mecA- and Tn554-specific DNA probes was used to identify polymorphs and determine their localization in chromosomal DNA preparations, and pulsed-field gel electrophoretic analysis of SmaI digests was used to determine chromosomal backgrounds. A major clone (and its variants) carrying the mecA polymorph I, Tn554 type E in the PFGE background of pattern A, accounted for 85% of all MRSA tested in 1992-1993 and 66% in 1994-1995. This clone is closely related to the epidemic Iberian clone that was associated with outbreaks in Spain during 1989-1993 and was endemic in 1992-1993 in two hospitals in Lisbon (Portugal).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Southern
  • Cross Infection / microbiology
  • DNA Fingerprinting
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / isolation & purification
  • Drug Resistance, Multiple / genetics*
  • Genotype
  • Humans
  • Methicillin Resistance / genetics*
  • Microbial Sensitivity Tests
  • Nucleic Acid Hybridization
  • Phenotype
  • Polymorphism, Genetic
  • Portugal / epidemiology
  • Spain / epidemiology
  • Staphylococcal Infections / epidemiology
  • Staphylococcal Infections / microbiology*
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / genetics*


  • DNA, Bacterial