Mechanisms of antimicrobial resistance

Abstract

Antimicrobial resistance or AMR is a phenomenon that is characterized by a resistance towards antibiotics found in bacteria. It has become especially prevalent in the last 5 decades due along with development of antibiotics which are often misused. Bacteria obtain these resistant characteristics from mutation and all other mechanisms of acquiring new genes. A variety of resistant mechanisms are present in bacteria, each of which are better suited for certain antibiotics which include: Inactivation of the drug, alteration of target sites, alteration of cell permeability, and efflux pumps. There are two main ways which drugs are inactivated. Firstly, the drug is completely degraded and second, the drug is inactivated by binding to a chemical group. Both are done by enzymes within the bacteria. Alteration of drug sites involves the mutation of potential targets within the cell for antibiotics. This often takes the form of changing its chemical structure, inhibiting the target, or increasing in potential target sites. Alteration of permeability are often mutations in the cell membrane so that antibiotics are unable to enter the cell. This often involves the alteration of porins which are channels that allow foreign substance into the cell. The mechanism of efflux pumps involves the action of removing antibitics that are already in the cell. Efflux pumps are believed to be an innate factor of bacteria originally being used to remove potentially harmful but natural substances.