The molecular epidemiology of methicillin-resistant Staphylococus aureus (MRSA) in a university hospital in Italy was studied in a five-month period in 1996, during which all S. aureus isolated were collected.
All MRSA isolates (95) and a sample of methicillin-susceptible S. aureus (20) were typed with a variety of phenotypic and genotypic methods.
Clonal identities were determined by pulsed-field gel electrophoresis (PFGE) of chromosomal SmaI digests and. for M RSA isolates, by probing ClaI digests with a mecA probe and a Tn554 probe.
Overall, MRSA represented 32.3% of all isolates. with very high percentages from the intensive care units (adult and neonatal).
PFGE after restriction with SmaI resolved genomic DNA of 95 MRSA strains into 26 major PFGE patterns.
The use of southern blot hybridization of ClaI genomic digests with mecA and Tn554 allowed us a significant increase in discrimination, differentiating at least 32 different clones.
Two major clones. however, each sharing common ClaI-mecA and Tn554 type and PFGE pattern as well as a common resistance phenotype, represented more than 50% of all MRSA isolates.
The recovery of these two clones in the majority of the isolates of adult and neonatal intensive care units, respectively, is indicative of typical nosocomial outbreaks and clonal spread.
It is concluded that intensive care units are major areas requiring preventative interventions.
Mots-clés Pascal : Italie, Europe, Homme, Infection nosocomiale, Résistance traitement, Staphylococcie, Bactériose, Infection, Epidémiologie, Staphylococcus aureus, Micrococcaceae, Micrococcales, Bactérie, Méticilline, Antibiotique, Antibactérien, Biologie moléculaire, Isolat clinique, Pénicilline dérivé, bêta-Lactamines, Résistance méticilline
Mots-clés Pascal anglais : Italy, Europe, Human, Nosocomial infection, Negative therapeutic reaction, Staphylococcal infection, Bacteriosis, Infection, Epidemiology, Staphylococcus aureus, Micrococcaceae, Micrococcales, Bacteria, Meticillin, Antibiotic, Antibacterial agent, Molecular biology, Clinical isolate, Penicillin derivatives, bêta-Lactams
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0127071
Code Inist : 002B05B02N. Création : 16/11/1999.