Staphylococcus Aureus - Treatment and Antibiotic Resistance

Treatment and Antibiotic Resistance

The treatment of choice for S. aureus infection is penicillin; in most countries, though, penicillin resistance is extremely common, and first-line therapy is most commonly a penicillinase-resistant β-lactam antibiotic (for example, oxacillin or flucloxacillin). Combination therapy with gentamicin may be used to treat serious infections, such as endocarditis, but its use is controversial because of the high risk of damage to the kidneys. The duration of treatment depends on the site of infection and on severity.

Antibiotic resistance in S. aureus was uncommon when penicillin was first introduced in 1943. Indeed, the original petri dish on which Alexander Fleming of Imperial College London observed the antibacterial activity of the Penicillium fungus was growing a culture of S. aureus. By 1950, 40% of hospital S. aureus isolates were penicillin-resistant; and, by 1960, this had risen to 80%.

Methicillin-resistant S. aureus, abbreviated MRSA and often pronounced /ˈmɜrsə/ or /ɛm ɑː ɛs eɪ/, is one of a number of greatly feared strains of S. aureus which have become resistant to most β-lactam antibiotics. MRSA strains are most often found associated with institutions such as hospitals, but are becoming increasingly prevalent in community-acquired infections. A recent study by the Translational Genomics Research Institute showed that nearly half (47%) of the meat and poultry in U.S. grocery stores were contaminated with S. aureus, with more than half (52%) of those bacteria resistant to antibiotics.

The article Methicillin-resistant Staphylococcus aureus contains related information on this topic

Researchers from Italy have identified a bacteriophage active against S. aureus, including methicillin-resistant strains (MRSA), in mice and possibly humans.