Efflux Pumps and Nosocomial Antibiotic Resistance: A Primer for Hospital Epidemiologists

Abstract

Bacterial resistance to antimicrobial agents, including multidrug resistance, is an increasing problem in health care in both community and hospital settings. Bacterial adaptability in circumventing antimicrobial action stems from an array of mutational resistance mechanisms and from the acquisition of resistance genes that are present on plasmids that can transfer between bacteria within and among species. Resistance is mediated by 1 or more mechanisms from 3 general categories: alteration or protection of the antimicrobial target, alteration of drug access to the target, and/or inactivation of the antimicrobial. Although there are multiple, often interesting variations of these mechanisms, resistance results from 1 or a combination of mechanisms from these 3 categories.