Gram Negative Resistance

Dr. Melissa O’Neal, ID Clinical Pharmacist at Tampa General Hospital, provides an overview of gram negative resistance in this fast-paced presentation. Dr. O’Neal begins by describing the general mechanisms of antimicrobial resistance, including cell-wall dependent mechanisms and chromosomal mechanisms. She covers the alteration of membrane porins, over expression of efflux pumps, mutations of drug binding sites, and the production of enzymes that degrade antimicrobials. Next, the speaker covers the beta-lactamases, enzymes that degrade beta-lactam antibiotics, including penicillins, cephalosporins, and carbapenems. The Ambler class classification system is also covered, which offers a helpful way to differentiate the beta-lactamases by type of antimicrobial affected. Amp C resistance is also reviewed, and examples are provided, Lastly, specific bacterial resistance mechanisms are reviewed by each gram negative organism in order to help with knowledge retention.