title: Phenotypic and genotypic variations within a single bacteriophage species.
abstract: BACKGROUND
  Although horizontal gene transfer plays a pivotal role in bacteriophage evolution, many lytic phage genomes are clearly shaped by vertical evolution. We investigated the influence of minor genomic deletions and insertions on various phage-related phenotypic and serological properties.
  
  
  RESULTS
  We collected ten different isolates of Pseudomonas aeruginosa bacteriophage ϕKMV. All sequenced genomes (42-43 kb, long direct terminal repeats) are nearly identical, which intuitively implied strongly similar infections cycles. However, their latent periods vary between 21 and 28 minutes and they are able to lyse between 5 and 58% of a collection of 107 clinical P. aeruginosa strains. We also noted that phages with identical tail structures displayed profound differences in host spectra. Moreover, point mutations in tail and spike proteins were sufficient to evade neutralization by two phage-specific antisera, isolated from rabbits.
  
  
  CONCLUSIONS
  Although all analyzed phages are 83-97% identical at the genome level, they display a surprisingly large variation in various phenotypic properties. The small overlap in host spectrum and their ability to readily escape immune defences against a nearly identical phage are promising elements for the application of these phages in phage therapy.
authors.affiliation: Laboratory of Gene Technology (LoGT), Katholieke Universiteit Leuven, Kasteelpark Arenberg 21 bus 2462, B-3001 Leuven, Belgium.
authors.forename: Pieter-Jan
authors.initials: PJ
authors.lastname: Ceyssens
authors.forename: Thea
authors.initials: T
authors.lastname: Glonti
authors.forename: Ndrew M
authors.initials: NM
authors.lastname: Kropinski
authors.forename: Rob
authors.initials: R
authors.lastname: Lavigne
authors.forename: Nina
authors.initials: N
authors.lastname: Chanishvili
authors.forename: Leonid
authors.initials: L
authors.lastname: Kulakov
authors.forename: Nino
authors.initials: N
authors.lastname: Lashkhi
authors.forename: Marina
authors.initials: M
authors.lastname: Tediashvili
authors.forename: Maya
authors.initials: M
authors.lastname: Merabishvili
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D044822:Biodiversity; D016679:Genome, Viral; D005838:Genotype; D058507:Host Specificity; D008969:Molecular Sequence Data; D010641:Phenotype; D011550:Pseudomonas aeruginosa / Q000821:virology*