Lack of Heteroresistance among Staphylococcus aureus Isolates with Vancomycin MICs of 2 Micrograms per Milliliter by Automated Testing

Vancomycin heteroresistance and methicillin-resistant Staphylococcus aureus.

Heteroresistance refers to the presence, within a larger population of fully antimicrobial-susceptible microorganisms, of subpopulations with lesser susceptibility. This phenomenon has been described in a wide range of microorganisms, but much recent attention has been directed toward its expression in Staphylococcus aureus. Although it has long been known that resistance to methicillin is char...

Determination of vancomycin and daptomycin MICs by different testing methods for methicillin-resistant Staphylococcus aureus.

Vancomycin and daptomycin MICs from 161 isolates of methicillin-resistant Staphylococcus aureus (MRSA) were compared using commercial and in-house broth microdilution, Etest, and common automated methods. Vancomycin Etest MICs were higher than those of other methods, whereas the MICs for daptomycin testing were comparable. Vancomycin MICs vary depending on the testing methodology.

Vancomycin heteroresistance in bloodstream isolates of Staphylococcus capitis.

Nine Staphylococcus capitis isolates from blood cultures of newborns were examined for resistance to vancomycin. MICs were within the susceptible range, but population profiling revealed a resistant subpopulation. Only isolates with the largest subpopulation were identified as heteroresistant to vancomycin by Etest. This finding may have therapeutic implications.

Vancomycin heteroresistance of Staphylococcus capitis 1 bloodstream isolates

Vancomycin Resistance Pattern of Staphylococcus Aureus among Clinical Samples

Abstract Background and Objective: Vancomycin is used for treatment of methicillin-resistant S. Aureus (MRSA) infections therefore, resistance to this antibiotic is increasing. We aimed to determine the antibiotic resistance pattern and frequency of vancomycin resistant S. Areas (VRSA) strains isolated from clinical samples. Material and Methods: In this cross-sectional study, 100 S. Aureus iso...