Hospital- and community-acquired
Staphylococcus aureus infections pose a substantial burden in terms of morbidity, mortality and health care costs. The introduction of new
antibiotics to counter this pathogen has frequently been closely followed by the emergence of resistant strains. Most significantly, S. aureus isolates resistant to
beta-lactams have become common, and many of these are also resistant to beta-lactamase-resistant
penicillins. The rapid spread of methicillin-resistant S. aureus (MRSA) clones across the world often results in hospital outbreaks, but implementation of appropriate control measures usually reduces prevalence to sporadic levels. However, the recent emergence of MRSA
infections in the community, affecting patients with no established risk factors for MRSA acquisition, is likely to impact significantly on future strategies for control of nosocomial MRSA. In contrast to other
antibiotic classes, S. aureus resistance to
glycopeptides did not emerge until nearly 40 years after their clinical introduction, and as a result this
drug class has remained the mainstay of treatment for MRSA
infections. However, a number of
vancomycin-intermediate S. aureus isolates have emerged worldwide and four fully resistant S. aureus isolates have been reported in the USA. This raises the concern that the current first-line treatment for MRSA
infection may become ineffective in an increasing proportion of cases in the near future. New classes of
antibiotic are urgently needed to treat
infections with this growing population of multidrug-resistant S. aureus, and the recently introduced
oxazolidinone linezolid and the cyclic
lipopeptide daptomycin are welcome additions to the ever-narrowing range of
therapies effective against this pathogen.