Cephamycin

Cephamycins are a group of beta-lactam antibiotics. They are very similar to cephalosporins, and the cephamycins are sometimes classified as cephalosporins.
Like cephalosporins, cephamycins are based upon the cephem nucleus. Unlike most cephalosporins, cephamycins are a very efficient antibiotic against anaerobic microbes.