Clinical and Laboratory Characteristics of Invasive Infections Due to Methicillin-Resistant Staphylococcus aureusIsolates Demonstrating a Vancomycin MIC of 2 Micrograms per Milliliter: Lack of Effect of Heteroresistant Vancomycin-Intermediate S. aureusPhenotype

ABSTRACTWe describe clinical and laboratory characteristics of invasive methicillin-resistant Staphylococcus aureus(MRSA) infections with vancomycin MICs of 2 µg/ml and compare heteroresistant-intermediate S. aureus(hVISA) to non-hVISA. Health care-associated community-onset infections were the most common and resulted in frequent complications and relapses. hVISA-infected patients were more likely to have been hospitalized in the year prior to MRSA culture.