Cloxacillin: A semi-synthetic antibiotic that is a chlorinated derivative of OXACILLIN.Floxacillin: Antibiotic analog of CLOXACILLIN.Penicillin G: A penicillin derivative commonly used in the form of its sodium or potassium salts in the treatment of a variety of infections. It is effective against most gram-positive bacteria and against gram-negative cocci. It has also been used as an experimental convulsant because of its actions on GAMMA-AMINOBUTYRIC ACID mediated synaptic transmission.Penicillinase: A beta-lactamase preferentially cleaving penicillins. (Dorland, 28th ed) EC 3.5.2.-.Penicillins: A group of antibiotics that contain 6-aminopenicillanic acid with a side chain attached to the 6-amino group. The penicillin nucleus is the chief structural requirement for biological activity. The side-chain structure determines many of the antibacterial and pharmacological characteristics. (Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1065)Fusidic Acid: An antibiotic isolated from the fermentation broth of Fusidium coccineum. (From Merck Index, 11th ed). It acts by inhibiting translocation during protein synthesis.Methicillin: One of the PENICILLINS which is resistant to PENICILLINASE but susceptible to a penicillin-binding protein. It is inactivated by gastric acid so administered by injection.Dicloxacillin: One of the PENICILLINS which is resistant to PENICILLINASE.Sarcina: A genus of gram-positive, anaerobic bacteria whose organisms divide in three perpendicular planes and occur in packets of eight or more cells. It has been isolated from soil, grains, and clinical specimens.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.CephalosporinaseAmpicillin: Semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic.Staphylococcal Infections: Infections with bacteria of the genus STAPHYLOCOCCUS.Penicillin V: A broad-spectrum penicillin antibiotic used orally in the treatment of mild to moderate infections by susceptible gram-positive organisms.Sulfadimethoxine: A sulfanilamide that is used as an anti-infective agent.beta-Lactamases: Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.Oxacillin: An antibiotic similar to FLUCLOXACILLIN used in resistant staphylococci infections.Cephalothin: A cephalosporin antibiotic.beta-Lactams: Four-membered cyclic AMIDES, best known for the PENICILLINS based on a bicyclo-thiazolidine, as well as the CEPHALOSPORINS based on a bicyclo-thiazine, and including monocyclic MONOBACTAMS. The BETA-LACTAMASES hydrolyze the beta lactam ring, accounting for BETA-LACTAM RESISTANCE of infective bacteria.