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Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
Published on: May 2, 2018
Evolution of Staphylococcus aureus under vancomycin selective pressure: the role of the small-colony variant
Justin R Lenhard1, Christof von Eiff2, Irene S Hong3
1Laboratory for Antimicrobial Pharmacodynamics, NYS Center of Excellence in Bioinformatics & Life Sciences, University at Buffalo, Buffalo, New York, USA School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, New York, USA.
Abstract:
Staphylococcus aureus small-colony variants (SCVs) often persist despite antibiotic therapy. Against a 10(8)-CFU/ml methicillin-resistant S. aureus (MRSA) (strain COL) population of which 0%, 1%, 10%, 50%, or 100% was an isogenic hemB knockout (Ia48) subpopulation displaying the SCV phenotype, vancomycin achieved maximal reductions of 4.99, 5.39, 4.50, 3.28, and 1.66 log10 CFU/ml over 48 h. Vancomycin at ≥16 mg/liter shifted a population from 50% SCV cells at 0 h to 100% SCV cells at 48 h, which was well characterized by a Hill-type model (R2>0.90).
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