Oxacillin sodium (Bactocill®) is an beta-lactam antibiotic in the penicillin class. It has been used particularly in the treatment of Staphylococcus aureus bacteria, and resistant strains are often called oxacillin-resistant Staphylococcus aureus (ORSA). β-lactam antibiotics are a broad class of antibiotics including penicillin derivatives, cephalosporins, monobactams, carbapenems and β-lactamase inhibitors; basically any antibiotic agent which contains a β-lactam nucleus in its molecular structure. ... Penicillin nucleus Penicillin refers to a group of β-lactam antibiotics used in the treatment of bacterial infections caused by susceptible, usually Gram-positive, organisms. ... Binomial name Staphylococcus aureus Rosenbach 1884 Staphylococcus aureus (which is occasionally given the nickname golden staph) is a bacterium, frequently living on the skin or in the nose of a healthy person, that can cause illnesses ranging from minor skin infections (such as pimples, boils, and cellulitis) and abscesses, to... ‹ The template below has been proposed for deletion. ... Electron micrograph of MRSA Methicillin-resistant Staphylococcus aureus (MRSA) is a specific strain of the Staphylococcus aureus bacterium that has developed antibiotic resistance to all penicillins, including methicillin and other narrow-spectrum β-lactamase-resistant penicillin antibiotics. ...