The disparate effects of bacteriophages on antibiotic-resistant bacteria

Clara Torres-Barceló

doi:10.1038/s41426-018-0169-z

Abstract

Faced with the crisis of multidrug-resistant bacteria, bacteriophages, viruses that infect and replicate within bacteria, have been reported to have both beneficial and detrimental effects with respect to disease management. Bacteriophages (phages) have important ecological and evolutionary impacts on their bacterial hosts and have been associated with therapeutic use to kill bacterial pathogens, but can lead to the transmission of antibiotic resistance. Although the process known as transduction has been reported for many bacterial species by classic and modern genetic approaches, its contribution to the spread of antibiotic resistance in nature remains unclear. In addition, detailed molecular studies have identified phages residing in bacterial genomes, revealing unexpected interactions between phages and their bacterial hosts. Importantly, antibiotics can induce the production of phages and phage-encoded products, disseminating these viruses and virulence-related genes, which have dangerous consequences for disease severity. These unwanted side-effects of antibiotics cast doubt on the suitability of some antimicrobial treatments and may require new strategies to prevent and limit the selection for virulence. Foremost among these treatments is phage therapy, which could be used to treat many bacterial infectious diseases and confront the pressing problem of antibiotic resistance in pathogenic bacteria. This review discusses the interactions between bacteriophages, antibiotics, and bacteria and provides an integrated perspective that aims to inspire the development of successful antibacterial therapies.

Highlights

Bacteriophages are viruses capable of infecting and killing bacteria
Antibiotic resistance genes (ARGs) in bacterial chromosomes or plasmids can be mobilized by phages during the infection cycle, a consequence of the inaccurate excision or encapsidation of the phage genome that allows for the incorporation of host genes by mistake
The results show that E. coli ARGs detected by qPCR in the phage fraction of wastewater matched those identified in the bacterial fraction but were present at lower abundances[20,21]

Summary

Introduction

Bacteriophages (hereafter referred to as phages) are viruses capable of infecting and killing bacteria. Antibiotic resistance genes (ARGs) in bacterial chromosomes or plasmids can be mobilized by phages during the infection cycle, a consequence of the inaccurate excision or encapsidation of the phage genome that allows for the incorporation of host genes by mistake. Such frequencies should be ~100-fold higher than observed transductants/pfu values because the final steps of recipient cell infection and the recombination of the ARG gene into the bacterial genome are no longer required.

Results

Conclusion