Viruses Must Overcome Challenges to Infect Bacteria in Nature

Molecular studies show phage-host interactions are more complicated than most laboratory studies suggest.

viral infection
Researchers studied molecular data on phages to discover how the viruses affect environmentally important bacteria in nature. Image courtesy of Environmental Molecular Sciences Laboratory

The Science

Viruses seem to easily infect bacteria, but most studies of viral infection focus on viruses and host cells tailored for lab experiments. Now, a team studied the interaction of viruses, called phages, and bacteria in nature. They noted multiple infection inefficiencies, suggesting the natural interactions are more complex than lab studies have shown.

The Impact

Phage research has benefited our understanding of nature and ourselves. It helped identify DNA as the hereditary material and described the nature of gene expression in microbes. However, studies of the interactions between phages and bacteria are largely limited to lab experiments. These studies feature optimal infection conditions. The natural environment is more complicated. This study broadens our knowledge of how efficiently phages infect a host in nature. Thus, scientists can develop better ecosystem models, devise more sustainable biotechnology, and improve human health.

Summary

Building on previous research, scientists from The Ohio State University, Pacific Northwest National Laboratory, and Environmental Molecular Sciences Laboratory (EMSL) studied vast amounts of data on proteins and the messenger RNA molecules associated with them to look at how efficiently two different phages infected similar bacteria. The bacterial strains are common in the environment, and their close relatives are found in soils, water, and humans. They affect nutrient turnover, health, and disease. By taking regular measurements as the infection progressed using the Orbitrap mass spectrometer and next-generation sequencers at EMSL, a Department of Energy Office of Science user facility, the team captured all the internal viral and bacterial changes. For the first time, the work identified multiple infection inefficiencies in such interactions—from poorer adsorption at the cell surface to intercellular responses by the host that repressed the phage’s ability to take over the host, express its genes, or make its proteins. These inefficiencies suggest phage-host interactions in nature are more complicated than traditional laboratory studies have shown. Results will help scientists better understand, predict, and enhance the functioning of microbial communities important to industry, agriculture, and human health.