| Autor: |
Schwalbe, R. S., Ritz, W. J., Verma, P. R., Barranco, E. A., Gilligan, R H., Gilligan, P H |
| Zdroj: |
Journal of Infectious Diseases; 1990, Vol. 161 Issue 1, p45-51, 7p |
| Abstrakt: |
Killing curves were used to characterize Staphylococcus haemolyticus isolates previously reported to contain subpopulations showing increased resistance to vancomycin. Results suggested that vancomycin and teicoplanin were ineffective at a concentration of 8 µg/ml and growth was seen between 24 and 48 h. Conversely, the lipopeptide antibiotic daptomycin at the same concentration rapidly killed tested strains by 6 h. Various staphylococcal strains were examined to determine if vancomycin resistance could be selected in all strains of staphylococci, was specie(s) restricted, or was unique to this patient—s clinical isolates. About 1 × 108 colony-forming units were added to melted brain-heart infusion agar plates containing 12 µg/ml of vancomycin. Plates were examined after 48 h for presence of resistant clones. Results indicated that selection for vancomycin resistance was restricted to S. haemolyticus strains. Further, all S. haemolyticus isolates that displayed a double zone of growth around imipenem agar diffusion discs (Impdz) contained stably resistant subpopulations. Vancomycin resistance could not be selected in imipenem-sensitive derivative clones. Impdz isolates that were recovered from geographically distinct locations displayed nearly identical SDS-PAGE protein profiles. It appears that a characteristic susceptibility pattern displayed byclinical isolates of S. haemolyticus may provide a marker for those strains that contain subpopulations having increased resistance to vancomycin. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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