Background Since the discovery of the vancomycin-resistant Staphylococcus aureus (VRSA) strain Mu50 (minimum inhibitory concentration [MIC] 8 mg/L), there has been concern about the potential spread of such strains throughout Japanese hospitals.
Two important questions need to be answered : (1) what is the prevalence of VRSA, and (2) by what mechanism does vancomycin resistance occur.
Methods The vancomycin susceptibilities of three methicillin-resistant S aureus (MRSA) strains (Mu50, Mu3, and H1) and the methicillin-susceptible S aureus type strain FDA209P were compared by MIC determinations and population analysis.
Mu3 (MIC 3 mg/L) was isolated from the sputum of a patient with pneumonia after surgery who had failed vancomycin therapy.
H1 (MIC 2 mg/L), which is a representative vancomycin-susceptible MRSA strain, was isolated from a patient with pneumonia who responded favourably to vancomycin therapy.
Subclones of Mu3 with increased resistance against vancomycin were selected with serial concentrations of vancomycin and their MICs were determined.
The prevalence of VRSA and Mu3-like strains in Japanese hospitals was estimated by population analysis from 1149 clinical MRSA isolates obtained from 203 hospitals throughout Japan.
The genetic traits of the Mu3 and Mu50 strains were compared with clonotypes of MRSA from around the world.
Findings Mu3 and Mu50 had an identical pulsed-field gel electrophoresis banding pattern. (...)
Mots-clés Pascal : Staphylococcus aureus, Micrococcaceae, Micrococcales, Bactérie, Epidémiologie, Résistance chimique, Vancomycine, Réaction hétérogène, Etude comparative, Concentration minimale inhibitrice, Prévalence, Homme, Japon, Asie, Evaluation, Glycopeptide, Polypeptide, Bactériose, Infection, Antibiotique, Antibactérien, Activité biologique
Mots-clés Pascal anglais : Staphylococcus aureus, Micrococcaceae, Micrococcales, Bacteria, Epidemiology, Chemical resistance, Vancomycin, Heterogeneous reaction, Comparative study, Minimum inhibitory concentration, Prevalence, Human, Japan, Asia, Evaluation, Glycopeptide, Polypeptide, Bacteriosis, Infection, Antibiotic, Antibacterial agent, Biological activity
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0042263
Code Inist : 002B02S02. Création : 17/04/1998.