WAYNE STATE UNIV DETROIT MI DEPT OF IMMUNOLOGY AND MICROBIOLOGY
A protease from Pseudomonas aeruginosa having collagenase activity exhibited lethal and dermonecrotic properties. It was purified 1500-fold and was capable of hydrolyzing collagen both in vitro and in vivo. The enzyme was assayed in mice by a number of routes and was found to be most toxic when administered into the lungs. This resulted in confluent pulmonary hemorrhage. Five standard methods of extracting endotoxin were employed in an effort to establish its presence in Pseudomonas aeruginosa as well as to make comparative evaluations of its biological and chemical properties. Of the five preparations, aqueous phenol extracted endotoxin exhibited the greatest degree of lethality. The LD50 was 450 microgram dry weight when administered intravenously and 840 microgram intraperitoneally. No lethality was observed when endotoxin was administered intranasally. Lethality appeared to be associated with the core region of the lipopolysaccharide molecule, while no correlation between lethality and lipid content was detected.