Emergence of a strain of methicillin-resistant Staphylococcus aureus with decreased susceptibility to vancomycin 7 months after treatment with glycopeptide antibiotics
Cheng Len Sy, Susan Shin-Jung Lee, Kuan-Sheng Wu, Hung-Chin Tsai, Yung-Ching Liu, Yao-Shen Chen
Corresponding author. Section of Infectious Diseases, Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
Background and purpose:
This case report describes a methicillin-resistant Staphylococcus aureus isolated repeatedly from the blood of a patient with community-acquired endocarditis who developed a four-fold increase in the minimal inhibitory concentration of vancomycin and daptomycin 7 months after his last exposure to glycopeptide antibiotics. This is contrary to the expected situation in which antimicrobial resistance tends to decrease after a patient is no longer exposed to vancomycin.
Daptomycin, Glycopeptide, Resistance, Staphylococcus aureus, Vancomycin