Chromosomal DNA deletion confers phage resistance to Pseudomonas aeruginosa

Sci Rep. 2014 Apr 28;4:4738. doi: 10.1038/srep04738.

Abstract

Bacteria develop a broad range of phage resistance mechanisms, such as prevention of phage adsorption and CRISPR/Cas system, to survive phage predation. In this study, Pseudomonas aeruginosa PA1 strain was infected with lytic phage PaP1, and phage-resistant mutants were selected. A high percentage (~30%) of these mutants displayed red pigmentation phenotype (Red mutant). Through comparative genomic analysis, one Red mutant PA1r was found to have a 219.6 kb genomic fragment deletion, which contains two key genes hmgA and galU related to the observed phenotypes. Deletion of hmgA resulted in the accumulation of a red compound homogentisic acid; while A galU mutant is devoid of O-antigen, which is required for phage adsorption. Intriguingly, while the loss of galU conferred phage resistance, it significantly attenuated PA1r in a mouse infection experiment. Our study revealed a novel phage resistance mechanism via chromosomal DNA deletion in P. aeruginosa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteriophages / physiology*
  • Chromosomes, Bacterial*
  • DNA Transposable Elements
  • DNA, Bacterial
  • Disease Models, Animal
  • Female
  • Gene Deletion
  • Genes, Bacterial
  • Genome, Bacterial
  • Genomics
  • Mice
  • Mutation
  • Pancreatitis-Associated Proteins
  • Pigments, Biological / biosynthesis
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / metabolism
  • Pseudomonas aeruginosa / virology*
  • Sequence Deletion*

Substances

  • DNA Transposable Elements
  • DNA, Bacterial
  • Pancreatitis-Associated Proteins
  • Pigments, Biological
  • REG3A protein, human