Development of Reduced Vancomycin Susceptibility in Methicillin-Susceptible Staphylococcus aureus
SK Pillai, C Wennersten… - Clinical Infectious …, 2009 - academic.oup.com
SK Pillai, C Wennersten, L Venkataraman, GM Eliopoulos, RC Moellering Jr, AW Karchmer
Clinical Infectious Diseases, 2009•academic.oup.comBackground. Most cases of reduced vancomycin susceptibility in Staphylococcus aureus
reported in the literature have been in methicillin-resistant strains. We report the
development of reduced vancomycin susceptibility in a series of clonally related, methicillin-
susceptible S. aureus (MSSA) clinical isolates. This isogenic series permitted us to
determine whether the evolution of reduced vancomycin susceptibility in MSSA is similar to
that seen in MRSA. Methods. Differences in vancomycin population analysis profiles; …
reported in the literature have been in methicillin-resistant strains. We report the
development of reduced vancomycin susceptibility in a series of clonally related, methicillin-
susceptible S. aureus (MSSA) clinical isolates. This isogenic series permitted us to
determine whether the evolution of reduced vancomycin susceptibility in MSSA is similar to
that seen in MRSA. Methods. Differences in vancomycin population analysis profiles; …
Abstract
Background. Most cases of reduced vancomycin susceptibility in Staphylococcus aureus reported in the literature have been in methicillin-resistant strains. We report the development of reduced vancomycin susceptibility in a series of clonally related, methicillin-susceptible S. aureus (MSSA) clinical isolates. This isogenic series permitted us to determine whether the evolution of reduced vancomycin susceptibility in MSSA is similar to that seen in MRSA.
Methods. Differences in vancomycin population analysis profiles; chemical autolysis; vancomycin, oxacillin, and daptomycin minimum inhibitory concentrations; and bactericidal activities were examined.
Results. Progressive vancomycin resistance correlated with increasing daptomycin nonsusceptibility. Chemical autolysis and the bactericidal activity of vancomycin, oxacillin, and daptomycin were reduced in the final, vancomycin-intermediate S. aureus isolate, compared with the vancomycin-susceptible MSSA progenitor.
Conclusions. Clinicians should recognize that reduced vancomycin susceptibility can occur in S. aureus irrespective of background methicillin susceptibility and that development of intermediate vancomycin susceptibility in MSSA may result in increased tolerance to several classes of anti-staphylococcal antibiotics.
Oxford University Press