Antibiotic resistance genes (ARGs) as environmental emerging contaminants

Background and Aim : Improper use of antibiotics has led to their entry into the environment and the development of antibiotic-resistant genes in many bacteria. Many of these resistant genes are found in microorganisms distributed in a variety of environments, such as soil, water, and wastewater. The aim of this review study was to investigate environmentally resistant genes and drugs that have developed resistance in the body of microorganismsMethods : In this review study, articles entitled "Drug Resistance" and "Environmental Microorganisms" were used and then information from ۳۰ appropriate articles was extracted.Results : Environmental ARGs are chiefly developed by the following mechanisms; Target bypass (like dfrA۱, A۵, A۷, A۱۲, A۱۵, A۱۷), which demonstrates mutation changes or loss on the enzymes has led to the unreachability of antibiotics for the target enzyme, Efflux pumps (such as cmlA۱ and A۵), which affects structural cellular membrane and consequently decreases intracellular concentration of antibiotics,Target modification (like ermA, B,C, E, F, T, V, and X;mecA;penA) which exhibits the alternation of antibiotics activation sites and finally Antibiotic inactivation (such as blaOXA-۱,blaOXA-۲,blaOXA-۱۰,blaOXA-۳۰,andblaPSE-۱) which inactivate antibiotic molecules directly. beta-lactams, sulfonamides and tetracycline were dominant ARGs detected in the environment.Conclusion : ARGs are found in all media and it is very difficult to remove them from the environment so they are called ‘easy-to-get, hard-to-lose’pollutants. Since they can be exchanged among environmental micro-organisms of different genera their possible human health risk should be considered.

کلیدواژه ها:

Antibiotic resistance gene ، Environment ، microorganisms