Lysogeny and Phage Resistance in Pseudomonas aeruginosa.

Summary When 95 strains of Ps. aeruginosa were assayed for lysogenicity on a series of indicator strains, all bacteria were found to be lysogenic. From the patterns of lysogenicity obtained with respect to the indicators we conclude that the majority of the 95 strains tested were lysogenic for more than one bacteriophage. When the patterns of lysogenicity obtained in this study were compared with patterns of phage sensitivity with respect to 12 bacteriophages, it appeared that the lysogenicity patterns showed more utility with respect to grouping strains of this organism. Approximately 30% of the strains tested were found to be untypable with respect to the bacteriophages used, whereas all strains could be typed on the basis of lysogenicity patterns. Finally, the resistance of a given strain of Ps. aeruginosa to a series of bacteriophages appeared to be related to the degree of lysogenicity exhibited on a series of indicator bacteria.