Mechanisms of antimicrobial resistance development in bacteria

Abstract

Antimicrobial resistance poses a significant risk to animal health by reducing the effectiveness of the treatment and prevention of many infections caused by bacteria. Antibiotic resistance threatens human health by transmitting resistant strains of microorganisms or resistance genes from animals to humans through the food chain. Life-threatening infections that were previously manageable can become incurable through antimicrobial resistance. Antimicrobial resistance can be divided into two main types: natural and acquired. Natural bacterial resistance is associated with the absence or inaccessibility of target cites for the action of certain antimicrobial agents. The acquired resistance is specific and associated with the acquisition of extraneous resistance genes or mutational modification of chromosomal target genes. The resistance of bacteria to antimicrobial drugs varies depending on the antimicrobial agent, species or genus of bacteria, and the mechanism of resistance. Resistance to the same antimicrobial agent can be mediated by different resistance mechanisms. In some cases, the same resistance gene or mechanism are related to a wide variety of bacteria, whereas in other cases, resistance genes or mechanisms are restricted to certain bacterial species or genera. Bacterial resistance to different classes of antibiotics with common mechanisms often leads to the multidrug resistance. The data presented in this review focuses exclusively on the resistance genes and mechanisms found in bacteria of animal origin and on antimicrobials used in the veterinary medicine. For better coverage of the topic, information on the mechanisms of resistance is presented separately for each class of antimicrobial agents.