bacteriophages
Research Article | Ecological and Evolutionary ScienceSelection for Reducing Energy Cost of Protein Production Drives the GC Content and Amino Acid Composition Bias in Gene Transfer AgentsKin selection and group selection remain controversial topics in evolutionary biology. We argue that these types of selection are likely to operate in bacterial populations by showing that bacterial gene transfer agents (GTAs), but not related viruses, evolve under conditions of positive selection for the reduction of the energy cost of GTA particle production. We hypothesize that GTAs are dedicated devices mediating the survival of...
Editor's Pick Research Article | Host-Microbe BiologyProbiotic Properties of Escherichia coli Nissle in Human Intestinal OrganoidsProbiotic, or beneficial, bacteria, such as E. coli Nissle, hold promise for the treatment of human disease. More study is needed to fully realize the potential of probiotics. Safety and efficacy studies are critically important; however, mice are poor models for many human intestinal diseases. We used stem cell-derived human intestinal organoid tissues to evaluate...
Research Article | Therapeutics and PreventionTargeting Hidden Pathogens: Cell-Penetrating Enzybiotics Eradicate Intracellular Drug-Resistant Staphylococcus aureusThe increasing prevalence of antibiotic-resistant bacteria is one of the most urgent problems of our time. Staphylococcus aureus is an important human pathogen that has acquired several mechanisms to evade antibiotic treatment. In addition, S. aureus is able to invade and persist within human cells...
Research Article | Molecular Biology and PhysiologyProtein-Mediated and RNA-Based Origins of Replication of Extrachromosomal Mycobacterial ProphagesBacteriophages are the most abundant biological entities in the biosphere and are a source of uncharacterized biological mechanisms and genetic tools. Here, we identify segments of phage genomes that are used for stable extrachromosomal replication in the prophage state. Autonomous replication of some of these phages requires a RepA-like protein, although most lack repA and use RNA-based systems for replication initiation. We...
Research Article | Molecular Biology and PhysiologyParallel Genomics Uncover Novel Enterococcal-Bacteriophage InteractionsWe lack fundamental understanding of how phage infection influences bacterial gene expression and, consequently, how bacterial responses to phage infection affect the assembly of polymicrobial communities. Using parallel genomic approaches, we have discovered novel transcriptional regulators and metabolic genes that influence phage infection. The integration of whole-genome transcriptomic profiling during phage infection has revealed...
Research Article | Host-Microbe BiologyCharacteristics of Wetting-Induced Bacteriophage Blooms in Biological Soil CrustThis work forms part of an overarching research theme studying the effects of a changing climate on biological soil crust (biocrust) in the Southwestern United States. To our knowledge, this study was the first to characterize bacteriophages in biocrust and offers a view into the ecology of phages in response to a laboratory wetting experiment. The phages identified here represent lineages of Caudovirales, and we found that the...
Editor's Pick Research Article | Host-Microbe BiologyBacteriophage Adherence to Mucus Mediates Preventive Protection against Pathogenic BacteriaThe mucosal surfaces of animals are habitat for microbes, including viruses. Bacteriophages—viruses that infect bacteria—were shown to be able to bind to mucus. This may result in a symbiotic relationship in which phages find bacterial hosts to infect, protecting the mucus-producing animal from bacterial infections in the process. Here, we studied phage binding on mucus and the effect of mucin on phage-bacterium interactions. The...
Research Article | Ecological and Evolutionary ScienceResistance Evolution against Phage Combinations Depends on the Timing and Order of ExposureGlobally rising rates of antibiotic resistance have renewed interest in phage therapy where combinations of phages have been successfully used to treat multidrug-resistant infections. To optimize phage therapy, we first need to understand how bacteria evolve resistance against combinations of multiple phages. Here, we use simple laboratory experiments and genome sequencing to show that the timing and order of phage exposure determine...
Editor's Pick Research Article | Ecological and Evolutionary SciencePseudomonas aeruginosa Interstrain Dynamics and Selection of Hyperbiofilm Mutants during a Chronic InfectionBacteria adapt to infections by evolving variants that are more fit and persistent. These recalcitrant variants are typically observed in chronic infections. However, it is unclear when and why these variants evolve. To address these questions, we used a porcine chronic wound model to study the evolutionary dynamics of Pseudomonas aeruginosa in a mixed-strain...
Research Article | Molecular Biology and PhysiologyEvolution of Superinfection Immunity in Cluster A MycobacteriophagesMany aspects regarding superinfection, immunity, virulence, and the evolution of immune specificities are poorly understood due to the lack of large collections of isolated and sequenced phages with a spectrum of genetic diversity. Using a genetically diverse collection of Cluster A phages, we show that the classical and relatively straightforward patterns of homoimmunity, heteroimmunity, and virulence result from interactions between...