#10 · Genomics

Selection and phage-bacteria dynamics shape bacterial and phage genetic variation

The common thread is how selection and phage-bacteria interactions structure genetic variation and population dynamics. A reusable Wright-Fisher-based model with negative frequency-dependent selection on the pneumococcal accessory genome explains vaccine replacement and guides surveillance timing across vaccine introductions. A dynamical-systems analysis of a K. pneumoniae-phage model calibrated in vitro finds that quasineutral equilibria govern clearance of resistant strains and shape coexistence. A soil study reports higher microdiversity in temperate than in virulent bacteriophages, distinguishing these lifestyles by within-population diversity. What is new is the explicit transfer of a selection framework to surveillance design for a bacterial population, while the phage studies address coexistence and clearance dynamics rather than surveillance.