Gram-Negative Bacterial Resistance

The rapid worldwide spread of antimicrobial resistance among gram-negative bacteria is driven by a complex interplay of human, environmental, and health care-associated factors and accelerated by mobile genetic elements that facilitate the dissemination of resistance genes. Resistance in gram-negative bacteria arises primarily through reduced drug entry, active drug efflux, modification of antibiotic targets, and enzymatic drug inactivation, most notably through β-lactamase production. Clinically important resistant pathogens include extended-spectrum β-lactamase-producing Enterobacterales, carbapenem-resistant Enterobacterales, Pseudomonas aeruginosa with difficult-to-treat resistance, and carbapenem-resistant Acinetobacter baumannii. Limited access to effective antibiotics and the continued emergence of resistance to available agents pose substantial challenges to the management of these infections. Appropriate management requires timely and accurate diagnostics, targeted use of newer β-lactam agents, effective source control, and judicious selection of treatment durations.