Host control by phage
We study different aspects of bacteria control by temperate phages:
Host behaviour
Molecular mechanisms
Evolution
Our research
Phages are bacterial killers, but they can also integrate into bacterial DNA and replicate together with their host as a prophage. At the Dragoš Research Group our work focuses on research relating to the relationship between temperate phage and bacteria.
Phage can change the physiology, social interactions and evolution of its bacterial host. We investigate this relationship using a number of different methods including; evolutionary, genetic, and ecological aspects of these interactions, using bioinformatics, molecular biology, and microbiological approaches.
Our model phage-host system is SPbetavirus and Bacillus subtilis, a cosmopolitan spore-forming bacterium known for PGPR and probiotic properties. Bacillus subtilis is an important model organism for bacterial research and is widely used in industry to produce enzymes, antibiotics, and probiotics. Roughly 40% of natural B. subtilis isolates carry SPβ-like prophages.
Our Lab´s Areas of Research
Phage modulation of host morphology
Our research explores the interesting effects of selected SPbetaviruses on bacterial host morphology using a combination of real-time imaging, fluorescence microscopy and genome editing. We explore extreme cases where temperate phage alter the host cell wall, remodelling its shape.
Phage evolution via recombination
SPbetaviruses share long regions of homology and are known to recombine with each other during co-infection and form chimeric variants. We study these variant´s genomics, plaque morphologies and stability, to better understand evolution within phage genus.
Diversity of Bacillus prophages
We explore the diversity of all prophage elements identified within completed B. subtilis genomes available on NCBI, as well as genomes from our Department´s local collection. We cluster those elements into functional taxonomic group and analyse their abundance and diversity.
Host control via regulatory switch mechanism
SPbetaviruses can act as a phage regulatory switch when they integrate into functional bacterial loci, inactivating them. Upon excision from their attachment sites, these phages enable the reconstitution and expression of the affected bacterial genes. Such integration and excision influence bacterial phenotypes, such as the properties of bacterial spores. We have developed molecular tools to track phage integration and excision within host cells. We investigate the dynamics of phage regulatory excision across different bacterial strains. We also study phenotypic traits controlled by regulatory switch mechanisms, such as spore properties.
Phage-encoded bacteriocins, phage as s as mediators of interbacterial competition
Our work has shown that phages can carry biosynthetic gene clusters encoding antimicrobial compounds, making them active players in bacterial warfare. We investigate the role of phage-encoded bacteriocin in vertical and horizontal phage transmission. We also investigate how the lysogeny for certain Spbetaviruses can influence the kin/non-kin phenotype of the host.
Phage vs host control of lysogeny-lysis dynamics and gene expression
We compare lysis-lysogeny dynamics in the collection of lysogens, which differ either with phage or host genetic background. We also perform transcriptomics studies to better understand phage-host interactions at the molecular level, especially focusing on genes that are relevant during lysogeny and on experimental conditions where prophages exhibit interesting gene expression profiles.
Phage Genome Synteny and Gene Conservation
We developed synphage, a bioinformatics pipeline for visualizing gene synteny within phage genomes. This tool helps us study gene order and function conservation across bacteriophages, providing insights into their evolution and genetic architecture. For more information on Synphage link
Research funded by
