New insights into the vast diversity of nature’s most abundant viruses, the bacteriophages

Amazing stuff! Bacteriophage coexistence and heterogeneity.

"... A new study reveals a different story, suggesting that multiple phage species can coexist even when competing for a single, genetically identical population of bacterial cells.

The reason, researchers say, is that each species of phage has its own “niche,” with each virus specializing on a subpopulation of bacterial cells that have different growth phenotypes.  ...

“Our study similarly suggests that we’ve underestimated niche availability for phages, and how differing growth stages of host cells alone can help explain the abundance and diversity of phage species seen in nature.” ..."

From the editor's summary and abstract:

"Editor’s summary

Bacteriophages, the viruses that parasitize bacteria, are exceedingly diverse. The mechanisms that drive such phage diversity are unknown but have implications for all types of microbial communities, from those living in hot springs to those residing in our gut. ... investigated phage community dynamics experimentally by passaging wild-caught phage communities on a stable clone of Escherichia coli. The authors found that multiple phage species can stably coexist because of phage preference for different variants in growth phenotype that spontaneously emerge in populations of host bacteria. ...

Abstract

Bacteriophages are the most abundant and phylogenetically diverse biological entities on Earth, yet the ecological mechanisms that sustain this extraordinary diversity remain unclear. In this study, we discovered that phage diversity consistently outstripped the diversity of their bacterial hosts under simple experimental conditions. We assembled and passaged dozens of diverse phage communities on a single, nonevolving strain of Escherichia coli until the phage communities reached equilibrium. In all cases, we found that two or more phage species coexisted stably, despite competition for a single, clonal host population. Phage coexistence was supported through host phenotypic heterogeneity, whereby bacterial cells adopting different growth phenotypes served as niches for different phage species. Our experiments reveal that a rich community ecology of bacteriophages can emerge on a single bacterial host."

New insights into the vast diversity of nature’s most abundant viruses | Yale News "A new Yale-led study offers insights into the “social lives” of viruses — findings that might advance  the fight against antibiotic resistance."

Diverse phage communities are maintained stably on a clonal bacterial host (no public access)

A petri dish with a lawn culture of E.coli and different phage species in each spot. The whiter spots on the plate shows where the phage has killed the bacteria causing the petri dish to become transparent and allowing a white light to shine through.