cephalosporin cephalosporin the cephalosporins (sg. /ˌsɛfələˈspɔːrɪn, ˌkɛ-, -loʊ-/) are a class of β-lactam antibiotics originally derived from the fungus acremonium, which was previously known as cephalosporium. cephalosporindrug classcore structure of the cephalosporinsclass identifiersusebacterial infectionatc codej01dbiological targetpenicillin binding proteinsclinical datadrugs.comdrug classes