Bacteriophages may play key role in acquisition and mobilization of antibiotic resistance genes

Dec 17 2016

Scientists at the Catalan Institute for Water Research (ICRA) have carried out a comprehensive analysis of several viromes from different habitats to explore whether bacteriophages (viruses that infect bacteria) harbor antibiotic resistance genes. The team demonstrated that while human-associated viromes do not or rarely carry resistance genes, viromes from non-human sources (e.g., pig feces, raw sewage, and freshwater and marine environments) contain a large reservoir of resistance genes. Their work is described in the journal Environmental Pollution.

“These findings suggest that phages may play a more significant role in the acquisition and mobilization of antibiotic resistance genes than previously expected”, says Dr. Jose L. Balcazar, a Ramon y Cajal research scientist and senior author of the study.

Dr. Balcazar and his colleagues have previously received attention for their work on the prevalence of antibiotic resistance genes in treated wastewater effluents and receiving water bodies.

In this new study, several viromes (community of viruses) from humans, animals, and different environments worldwide were screened for sequences similar to those associated with antibiotic resistance genes. The results showed that genes encoding major facilitator superfamily transporters and beta-lactamases were found in all analysed viromes regardless their origin. The presence of these resistance genes in bacteriophages is of particular concern, because these genes may eventually be transferred to bacteria, making them resistant to antibiotics. Considering that bacteriophages have the potential to transfer genetic material between bacteria, they play an important role in the evolution and ecology of bacterial species. However, the contribution of bacteriophages to the acquisition and spread of antibiotic resistance has been partially explored in environmental settings. So these findings suggest that the role of bacteriophages should be taken into account in the development of strategies for tackling antibiotic resistance. This work was funded by the first joint call of the Water Joint Programming Initiative (JPI) and the Spanish Ministry of Economy and Competitiveness.