Antibiotic resistance in gram-positive bacteria: epidemiological aspects.

The emergence and spread of antibiotic resistance in gram-positive bacterial pathogens has become an increasing problem. There has been a dramatic increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci and enterococci. This is mainly due to the clonal dissemination of certain epidemic multiply-resistant strains, for example, those of MRSA and S. pneumoniae, as well as to the spread of resistance genes as exemplified by those causing glycopeptide resistance in enterococci.