Genomic and phenotypic signatures of bacteriophage coevolution with the phytopathogen Pseudomonas syringae.

The rate and trajectory of evolution in an obligate parasite is critically dependent on those of its host(s). Adaptation to a genetically homogeneous host population should theoretically result in specialization, while adaptation to an evolving host population (i.e.

Understanding the Impacts of Bacteriophage Viruses: From Laboratory Evolution to Natural Ecosystems.

Viruses of bacteria (bacteriophages or phage) have broad effects on bacterial ecology and evolution in nature that mediate microbial interactions, shape bacterial diversity, and influence nutrient cycling and ecosystem function. The unrelenting impact of phages within the microbial realm is the result, in large part, of their ability to rapidly evolve in response to bacterial host dynamics. The knowledge gained from laboratory systems, typically using pairwise interactions between single-host and single-phage systems, has made clear that phages coevolve with their bacterial hosts rapidly, somewhat predictably, and primarily by counteradapting to host resistance.

Water stress and disruption of mycorrhizas induce parallel shifts in phyllosphere microbiome composition.

Water and nutrient acquisition are key drivers of plant health and ecosystem function. These factors impact plant physiology directly as well as indirectly through soil- and root-associated microbial responses, but how they in turn affect aboveground plant-microbe interactions are not known. Through experimental manipulations in the field and growth chamber, we examine the interacting effects of water stress, soil fertility, and arbuscular mycorrhizal fungi on bacterial and fungal communities of the tomato (Solanum lycopersicum) phyllosphere.

Bacteriophage uptake by mammalian cell layers represents a potential sink that may impact phage therapy.

It is increasingly apparent that bacteriophages, viruses that infect bacteria and more commonly referred to as simply phages, have tropisms outside their bacterial hosts. Using live tissue culture cell imaging, we demonstrate that cell type, phage size, and morphology play a major role in phage internalization. Uptake was validated under physiological conditions using a microfluidic device.

Bacteriophage-Mediated Reduction of Bacterial Speck on Tomato Seedlings.

One crucial first step in bacteriophage therapy is choosing a phage to apply, which involves screening for effectiveness in a meaningful way. Increasingly, research suggests that tests of phage-mediated bacterial lysis poorly translate to effectiveness. We tested a seedling-based method for rapidly screening phage effectiveness .

Persistent effects of management history on honeybee colony virus abundances.

Infectious diseases are a major threat to both managed and wild pollinators. One key question is how the movement or transplantation of honeybee colonies under different management regimes affects honeybee disease epidemiology. We opportunistically examined any persistent effect of colony management history following relocation by characterising the virus abundances of honeybee colonies from three management histories, representing different management histories: feral, low-intensity management, and high-intensity "industrial" management.

Phage resistance evolution in vitro is not reflective of in vivo outcome in a plant-bacteria-phage system.

The evolution of resistance to parasites is fundamentally important to disease ecology, yet we remain unable to predict when and how resistance will evolve. This is largely due to the context-dependent nature of host-parasite interactions, as the benefit of resistance will depend on the abiotic and biotic environment. Through experimental evolution of the plant pathogenic bacterium Pseudomonas syringae and two lytic bacteriophages across two different environments (high-nutrient media and the tomato leaf apoplast), we demonstrate that de novo evolution of resistance is negligible in planta despite high levels of resistance evolution in vitro.

Investigating the association between armour coverage and parasite infection in an estuarine population of stickleback.

Background: When threespine stickleback colonized fresh water, they repeatedly evolved reduced armour plating via changes in allele frequency. This evolution is typically attributed to differential predation pressure between marine and freshwater environments. However, the chromosomal region containing is associated with many other phenotypes, including schooling, antipredator behaviour, and immunity.

Rapid quantification of bacteriophages and their bacterial hosts in vitro and in vivo using droplet digital PCR.

Viruses that infect bacteria, bacteriophages (phages), are well-studied across a wide range of environments and among diverse scientific fields. Nevertheless, current methods in phage research are lacking, in part due to limitations in culturability and the lack of a universal gene marker. Here, we demonstrate that droplet digital PCR (ddPCR) can be used as a repeatable and sensitive method to study bacteria-phage dynamics both in vitro and in vivo.