Gradual Alterations in Cell Wall Structure and Metabolism in Vancomycin-Resistant Mutants ofStaphylococcus aureus

K Sieradzki, A Tomasz - Journal of Bacteriology, 1999 - Am Soc Microbiol
K Sieradzki, A Tomasz
Journal of Bacteriology, 1999Am Soc Microbiol
In five vancomycin-resistant laboratory step mutants selected from the highly and
homogeneously methicillin-resistant Staphylococcus aureus strain COL (MIC of methicillin,
800 μg/ml; MIC of vancomycin, 1.5 μg/ml), the gradually increasing levels of resistance to
vancomycin were accompanied by parallel decreases in the levels of methicillin resistance
and abnormalities in cell wall metabolism. The latter included a gradual reduction in the
proportion of highly cross-linked muropeptide species in peptidoglycan, down-regulation of …
Abstract
In five vancomycin-resistant laboratory step mutants selected from the highly and homogeneously methicillin-resistant Staphylococcus aureus strain COL (MIC of methicillin, 800 μg/ml; MIC of vancomycin, 1.5 μg/ml), the gradually increasing levels of resistance to vancomycin were accompanied by parallel decreases in the levels of methicillin resistance and abnormalities in cell wall metabolism. The latter included a gradual reduction in the proportion of highly cross-linked muropeptide species in peptidoglycan, down-regulation of the production of penicillin-binding protein 2A (PBP2A) and PBP4, and hypersensitivity to β-lactam antibiotics each with a relatively selective affinity for the various staphylococcal PBPs; the PBP2-specific inhibitor ceftizoxime was particularly effective.
American Society for Microbiology