Vancomycin resistance in Staphylococcus aureus: a new challenge for infection control and antibiotic prescribing

Abstract

There have been several reported cases to date of Staphylococcus aureus (S. aureus) with decreased susceptibility to the glycopeptide antibiotics, particularly vancomycin. Such isolates have been termed VISA (vancomycin-intermediate S. aureus) or GISA (glycopeptide-intermediate S. aureus). These strains have developed in patients with pre-existing methicillin-resistant S. aureus (MRSA) infections treated with prolonged courses of the drug of choice, vancomycin. Resistance to vancomycin severely limits treatment options for these patients, highlighting the need to preserve the utility of the drug through restricted usage and the need for increased awareness of infection control measures to prevent acquisition of MRSA in the first instance. While vancomycin-resistant Enterococcus (VRE) has received significant attention in the scientific literature and the media, the clinical implications of a vancomycin-resistant strain of S. aureus, a more pathogenic and virulent organism, are far more significant. This review details the clinical features and microbiology of the isolates found so far, the use of vancomycin in staphylococcal infections and some of the measures necessary to prevent the development and spread of vancomycin resistance in Australia.