[NOVEL APPROACH TO COMPOSITION OF, BACTERIOPHAGE MIXTURES FOR ANTIBACTERIAL THERAPY].

AIM: Evaluate antibacterial activity of an experimental mixture of phages, belonging to several well-studied species. MATERIALS AND METHODS: The study was carried out using a group of 55 clinical Pseudomonas aeruginosa strains of various origins,- 4 mono-species mixtures of 32 virulent bacteriophages (species phiKZ-, phiKMV-, phiPBl-, PaP3-like phages) and 2 novel phages, phiMK (species PaK-P2) and phiPerm5. Activity of preparations from mono-species mixtures of bacteriophages ofvarious species were compared with activity of 3 commercial mixtures. Standard methods of study of bacteriophages were used: determination of lytic activity by seeding onto bacterial lawns of P. aeruginosa, restriction analysis of phage DNA for confirmation of their be- longing to certain species. RESULTS: Cumulative activity of 6 mono-species mixtures of virulent phages was shown to be similar to lytic activity of commercial therapeutic mixtures used against P. aeruginosa infections. 54 of 55 strains of clinical isolates of P: aeruginosa showed sensitivity to experimental mixtures composed of mono-species mixtures of bacteriophages. 53 strains were lysed by commercial preparations. Wherein the possibility of accidental inclusion of moderate -bacteriophages in the experimental mixture is excluded. CONCLUSION: A possibility of creation of highly active therapeutic antibacterial preparations against P. aeruginosa using mono-species mixtures of 6 species of lytic bacteriophages is shown Use of such a mixture in therapy of lung infections reduces the risk of emergence of bacterial strains with increased virulence and patho- genicity during prolonged administration.

[New temperate Pseudomonas aeruginosa phage, phi297: specific features of genome structure].

The genome structure and some specific features of temperate Pseudomonas aeruginosa phage phi297 are considered. Analysis of sequencing data and genome annotation suggest that the phi297 genome displays a mosaic structure, which has formed through combining gene blocks from bacteria of taxonomically remote groups and/or their phages. The results of a comparison of the phi297 DNA homology level and pattern with the genome sequences of the currently known related P. aeruginosa bacteriophages are interpreted from the perspective of assumed active migration of these phages between different bacterial species.