Methicillin-Resistant Staphylococcus aureus: Clinical and Laboratory Features

Abstract

Not long after the introduction of penicillin G for anti-staphylococcal therapy, penicillin G resistant strains of staphylococci were isolated and were found to produce penicillinase enzymes. In 1959 methicillin, a penicillinase resistant penicillin (PRP), was introduced in England for therapy of these strains. Within 2 years the first strains of methicillin-resistant Staphylococcus aureus (MRSA) were reported in that country. Subsequently, reports of MRSA infections throughout Europe appeared. Reports from Switzerland and Denmark indicated that 30% to 50% of all nosocomial S. aureus isolates and 40% of all S. aureus bacteremia isolates, respectively, were due to MRSA. Although sporadic reports of MRSA infections appeared in the US after 1960 the first documented outbreak of MRSA infections occurred at Boston City Hospital in 1968. Even today there is not a complete understanding of MRSA and its role in infectious diseases, however, a vast amount of information has accumulated and certain aspects of this information will be discussed.