The development of beta-lactam antibiotics in response to the evolution ofbeta-lactamases

beta -Lactam antibiotics, viz., penicillin, penicillin derivatives, cephalo sporins, cephamycins, carbapenems, monobactams, and monocarbams, are the mo st widely used of all antimicrobial classes by virtue of their high efficac y and specificity and the availability of several derivatives. The expressi on of one or several beta -lactamases (beta -lactam anti biotic-inactivatin g enzymes) represents the most widespread and the most clinically relevant resistance mechanism to these antibiotics. The development of beta -lactam antibiotics has thus been a continuous battle of the design of new compound s to withstand inactivation by the ever-increasing diversity of beta -lacta mases. This article traces antibiotic development in response to the evolut ion of betaP-lactamases.