Slime glycolipoproteins and the pathogenicity of various strains of Pseudomonas aeruginosa in experimental infection

Several strains of Pseudomonas aeruginosa were differentiated on the basis of the surface properties of the cells. Fisher immunotype, phage type, polysaccharide depolymerase type, and indirect hemagglutination reactions were used for this purpose. Each strain was then studied with respect to events known to occur during the experimental infection of mice with P. aeruginosa. The virulence of the viable cells varied significantly, although all strains were virulent. Glycolipoproteins were isolated from the slime of each strain, and they appeared similar chemically when they were analyzed for gross composition. The toxicity of the isolated glycolipoproteins varied insignificantly, except for that of one strain. Viable cells of each strain and their respective glycolipoproteins caused leukopenia, which occurs in the course of the lethal infection. The antisera to the glycolipoproteins protected mice in every case against infection by the homologous strains. In some cases, various degrees of cross-protection were observed.