penicillin

penicillin Historically the most famous of antibiotics, which kills many bacteria and some other microorganisms by attacking and destroying their cell walls. Penicillin is not effective against viruses, however, and specific penicillin types may be needed for certain bacteria. The different varieties of penicillin include amoxicillin, ampicillin, bacampicillin, carbenicillin, cloxicillin, dicloxicillin, nafcillin, oxacillin, penicillin G, and penicillin V. See also antibiotic.