Genome sequence comparison and superinfection between two related Pseudomonas aeruginosa phages, D3112 and MP22

A temperate transposable bacteriophage (MP22) was isolated from a Korean clinical isolate of Pseudomonas aeruginosa. It has a coliphage lambda-like morphology and a double-stranded DNA genome. The complete nucleotide sequence and annotation of the MP22 genome and its characteristics are presented. The MP22 genome is 36409 bp long with a G+C content of 64.2 mol%. The genome contains 51 proposed ORFs, of which 48 (94%) display synteny and significant nucleoticle and protein sequence similarity to the corresponding ORFs of the closely related phage, D31 12. Three of the predicted ORFs are unique proteins, whose functions are yet to be revealed. The phage c repressors exhibit striking dissimilarities and, when present as a single gene, did not show cross-immunity. In contrast, although an MP22 lysogen could be productively infected with D31 12, MP22 could not grow on a D31 12 lysogen, indicating a role of other D31 12 genes in superinfection exclusion.