Bacteriophages as Vehicles for Antibiotic Resistance Genes in the Environment

Antibiotic therapy represents one of the most important medical advances of the 20th century and is a valuable resource in combating infectious diseases. Its therapeutic use, however, has been associated with the emergence of antibiotic-resistant bacteria. There are many naturally occurring ways in which susceptible bacteria become resistant to antibiotics, including by chromosomal mutations and/or horizontal gene transfer. The latter is largely, although not exclusively, responsible for the development of antibiotic-resistant bacteria through various processes such as conjugation, transformation, and transduction [1]. Transduction is a mechanism of genetic exchange, which is mediated by independently replicating bacterial viruses called bacteriophages, or phages [2]. Although the acquisition of antimicrobial resistance by transduction has been demonstrated in clinically relevant bacterial species, this mechanism in environmental settings has not been fully explored. However, cutting-edge genomic technologies such as high-throughput sequencing have recently led to significant advances in our understanding of the contribution of phages to the spread of antibiotic resistance genes (ARGs). This article will, therefore, describe the current knowledge on the emergence and spread of antibiotic resistance in the environment, with special emphasis on the role of phages in the mobilization of ARGs. Understanding sources and mechanisms of antibiotic resistance is critical for developing effective strategies for reducing their impact on public and environmental health.