Core and accessory genome architecture in a group of Pseudomonas aeruginosa Mu-like phages

Area of Science:

• Microbiology
• Virology
• Genomics

Background:

• Pseudomonas aeruginosa is an opportunistic pathogen with various infecting bacteriophages.
• Mu-like bacteriophages infecting P. aeruginosa share genomic architecture and replication mechanisms with coliphage Mu.
• Understanding the genomic diversity of these phages is crucial for insights into their evolution.

Purpose of the Study:

• To sequence and compare the genomes of newly isolated Mu-like phages of P. aeruginosa.
• To analyze the genomic architecture and identify core and accessory genes within a group of P. aeruginosa transposable phages.
• To investigate the evolutionary and adaptive significance of genomic variations in these phages.

Main Methods:

• Genome sequencing of two novel Mu-like P. aeruginosa phages.
• Comparative genomic analysis of twelve P. aeruginosa phage genomes.
• Identification and categorization of core and accessory genes based on homology and function.

Main Results:

• The genomes of the two new phages are highly similar to each other and to other P. aeruginosa transposable phages.
• A common genomic architecture was observed across twelve analyzed P. aeruginosa phage genomes.
• Phage genomes consist of a conserved "core genome" and a variable "accessory genome" containing mostly short ORFs with unassigned functions.
• Variable genes are located in specific genomic regions.

Conclusions:

• The accessory genome likely contains genes that provide selective advantages for phage survival under specific host conditions.
• Phages may employ horizontal gene acquisition at specific loci for adaptation to host-imposed selective pressures.
• This study provides insights into the evolution and adaptation mechanisms of Mu-like bacteriophages infecting P. aeruginosa.