β-Lactam Antibiotics for Methicillin-Resistant Staphylococcus?

Oxacillin reduced the bacterial burden in mice infected with MRSA and repressed a gene associated with staphylococcal toxins.

Staphylococcus aureus achieves resistance to methicillin and other β-lactam antibiotics by acquiring the mecA gene on a mobile cassette chromosome. In addition to encoding for penicillin-binding protein 2a, conferring lower antibiotic binding affinity, this change leads to repression of the accessory gene regular (agr) operon, resulting in repression of several extracellular toxins. Because of this latter effect, researchers hypothesized that use of the β-lactam oxacillin in an experimental model of methicillin-resistant S. aureus (MRSA) infection would attenuate virulence and improve outcome.

To test this hypothesis, researchers infected mice intravenously with the USA300 MRSA strain and treated the mice with a therapeutic dosage (75 mg/kg/…

Reviewing Author

Neil M. Ampel, MD

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Editorial BoardsUpToDate

Leadership Positions in Professional SocietiesCoccidioidomycosis Study Group (Past President, Secretary, Treasurer)

Neil M. Ampel, MD

Disclosures

Editorial BoardsUpToDate

Leadership Positions in Professional SocietiesCoccidioidomycosis Study Group (Past President, Secretary, Treasurer)

β-Lactam Antibiotics for Methicillin-Resistant Staphylococcus?

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Reviewing Author