Characterization of lytic Pseudomonas aeruginosa bacteriophages via biological properties and genomic sequences.

Pseudomonas aeruginosa is an important cause of infections, especially in patients with immunodeficiency or diabetes. Antibiotics are effective in preventing morbidity and mortality from Pseudomonas infection, but because of spreading multidrug-resistant bacterial strains, bacteriophages are being explored as an alternative therapy. Two newly purified broad host range Pseudomonas phages, named vB_Pae-Kakheti25 and vB_Pae-TbilisiM32, were characterized as candidates for use in phage therapy. Morphology, host range, growth properties, thermal stability, serology, genomic sequence, and virion composition are reported. When phages are used as bactericides, they are used in mixtures to overcome the development of resistance in the targeted bacterial population. These two phages are representative of diverse siphoviral and podoviral phage families, respectively, and hence have unrelated mechanisms of infection and no cross-antigenicity. Composing bactericidal phage mixtures with members of different phage families may decrease the incidence of developing resistance through a common mechanism.