Summary

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of hospital-acquired bacteremia. Vancomycin is used for its treatment and strains with heterogeneous decreased sensitivity (h-VISA) have emerged that harbor subpopulations with reduced sensitivity to vancomycin. A case of intra-treatment bacteremia with vancomycin due to h-VISA MRSA is reported. The isolate shows sensitivity to vancomycin (CIMvan: 1 μg/mL), however E-test GRD suggests h-VISA (CIMvan: 2 μg/mL and MICtei: 8 μg/mL). The analysis of the population profile - area under the curve (PAP-AUC) validates this finding. He was switched to linezolid with clinical resolution.