Molecular basis of bacterial resistance to ampicillin

beta-lactam antibiotics are regularly used in medicine to control bacterial infections. However the overuse of these compounds in many human activities has led to dissemination of resistance determinants among pathogenic strains. Several mechanisms underlining beta-lactam resistance, e.g. enzymatic inactivation, PBP modification, active efflux, and finally the reduction of cell wall permeability have been identified. Understanding of such mechanisms is the first step to overcome the resistance. Ampiclllin was one of the first broad-spectrum amino penicillins introduced to therapy. Nowadays, five decades after the introduction of the antibiotic, ampicillin-resistant microbes are isolated all over the world. Current knowledge about the mechanisms involved in ampicillin resistance is presented in this review.