Phagovar determination of Pseudomonas aeruginosa and a comparison of the results with mitomycin C induced pyocin production.

One hundred Pseudomonas aeruginosa isolates recovered from intensive care areas of a university hospital and other clinical sites were characterized on the basis of their susceptibility to a set of twenty one phages. These strains were previously mitomycin C induced for their pyocin production and their serovars were also determined. All isolates identified on the basis of belonging to the same O-serovars and pyocin patterns, belonged to oe phagovar group. Strains which were non-identifiable with commercial antisera, had to be typed by both phagovar assay and mitomycin C induced pyocin production. Neither phagovar assay nor pyocin production alone gave enough individual characteristics of any one isolate, as to allow proper identification. Patterns with the same configurations in both phagovar and pyocin groups were detected among strains within entirely different O-serovar groups.