Efflux Pumps in Bacterial Cell: Mechanism of Multidrug Resistance to Antibiotics

Abstract Antibiotic resistance is one of the most significant problems in everyday clinical practice. The number of bacterial strains, as well as the number of antibiotics to which they are resistant, has been constantly increasing over the past few decades. One of the main causes of this resistance is excessive and improper use of antibiotics. The essential significance of this phenomenon is reflected in the increasingly difficult treatment of bacterial, primarily nosocomial, infections. There are numerous mechanisms by which bacteria achieve antibiotic resistance, but bacterial efflux pumps stand out as one of the most important. The basic function of these pumps is to return from the bacterial cell to the external environment all toxic substances that penetrate into it. Some of the pumps specifically transport one class of biocides while others do so for the entire spectrum of chemical compounds. Precisely due to the existence of a large number of such pumps, multidrug-resistant bacterial strains are formed, which is a significant problem in modern medicine. This review of the literature highlights the most important characteristics of bacterial efflux pumps, their families, antibiotics whose action is reduced or disabled, as well as bacteria which, thanks to their possession, have become multi-resistant pathogens.