Immunological study of Pseudomonas aeruginosa extracellular slime.

Crude extracellular slime (C-ES) was isolated from 15 laboratory strains of Pseudomonas aeruginosa. Glycolypoprotein (GLP) was prepared from partially purified C-ES by the phenol treatment method. Lipopolysaccharides (LPS) were isolated from P. aeruginosa and Salmonella typhi-murium. Some correlation has been found between the quantity of the produced C-ES and virulence of P. aeruginosa for mice. Toxicity (LD50 value) and the yield of GLP did not correlate with the strain virulence. C-ES and GLP contained hexose, protein and hexosamine. Heptoses (characteristic LPS components) were present in C-ES and practically absent from GLP. Paper chromatographic analysis of GLP showed the presence of uronic acids, galactose, glucose and ribose in all strains; GLP of most strains contained rhamnose and a low amount of mannose and several strains xylose. Uronic acids, galactose and, probably, ribose and mannose were characteristic ES components. C-ES and GLP were studied in active and passive mouse protection. ES isolated from P. aeruginosa strains of different O serogroups or immunotypes induced a marked cross protective response.