[Distribution of phage-resistant Pseudomonas aeruginosa strains]

The sensitivity of a number of P. aeruginosa clinical strains to virulent bacteriophages has been studied. Phage-resistant strains have been found to constitute a considerable proportion among the tested P. aeruginosa strains. The strains under study fall into 19 groups differing in their sensitivity to the bacteriophages used in this investigation. The strains belonging to some groups are phenotypically identical to experimentally obtained P. aeruginosa phage-resistant mutants PAO. The use of bacteriophage mutants has made it possible to demonstrate that in most cases the resistance of P. aeruginosa natural strains to type phi k phages is due to disturbances in their adsorption, whereas their resistance to type phi m and phi mn phages is, seemingly, not linked with disturbances in their capacity for adsorption on the cell membranes of the bacteria.