Characterization of methicillin-resistant Staphylococcus aureus strains susceptible to tobramycin.
Gentamicin-susceptible, methicillin-resistant, Stapylococcus aureus strains (GS-MRSA) emerged in 1992 in various Parisian hospitals and have subsequently been isolated from all French hospitals. This new GS-MRSA epidemic clone accounted for 50% of MRSA strains in 1996 and for 85% in 2000 in our hospital. We have observed a parallel increase in the prevalence of tobramycin and amikacin-susceptible GS-MRSA (TKS-MRSA). The number of TKS-MRSA strains per 100 MRSA strains has steadily increased from 3.1 in 1996 to 24.0 in 2000. Genotypic characterization of TKS-MRSA strains showed that these strains are a phenotypic variant of the dominant clone of GS-MRSA. To improve our understanding of the changes in methicillin-resistant Staphylococcus aureus (MRSA) susceptibility to non-beta-lactam antibiotics, gentamicin- and amikacin-susceptible MRSA (TKS-MRSA) from our acute-care hospital were compared with TKS-MRSA isolated from a long-term care hospital located in another region of France. The nature of the care facility did not seem to play a major role in the hospital dissemination of TKS-MRSA. We also found that changes in antibiotic use alone do not account for the emergence of these strains.
Talon
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Service d'Hygiène hospitalière et d'Epidémiologie moléculaire, Centre Hospitalier Universitaire Jean Minjoz, Besançon 25030, France. daniel.talon@ufc-chu.univ-fcomte.fr
Delière
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Bertrand
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D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D004196:Disease Outbreaks; D004363:Drug Utilization; D016521:Electrophoresis, Gel, Pulsed-Field; D005602:France / Q000453:epidemiology; D005798:Genes, Bacterial; D005838:Genotype; D006761:Hospitals; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics*; D014031:Tobramycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D014031:Tobramycin