Antimicrobial resistance mechanisms characteristic of clinically important gram-negative baccili

Antimicrobial resistance is a global public health issue and one of the most serious threats to the mankind today. Some bacterial strains have acquired resistance to most antimicrobial drugs and, therefore, new antibacterial agents that would overcome resistant strains are needed. In 2017, the World Health Organization published a list of priority antimicrobial-resistant pathogens. Most of these agents are gram-negative bacteria. Due to their structure, the gram-negative bacteria are more resistant to antimicrobials than gram-positive bacteria and cause significant morbidity and mortality worldwide. The main resistance mechanisms are: restricted drug absorption, modification of the target attack, inactivation of the antimicrobial drug by production of hydrolyzing enzymes and active drug efflux. These mechanisms may be innate or acquired by microorganisms, and understanding those mechanisms may create new treatment options for infectious pathology and may contribute to the development of new antimicrobial drugs that counter the microbial attempts to become resistant.