'In vivo' Role of 'Pseudomonas aerugionsa' Toxins and Host Response

In vitro and in vivo studies were performed on both endotoxin and collagenase obtained from Pseudomonas aeruginosa. The collagenase was extensively purified by both chemical and chromatographic technics and was subsequently assayed for potential toxic activity. The collagenase yielded a 72 hr LD50 value in mice of 148 enzyme units I.P., 288 units I.V. and 55 units intranasally. The subcutaneous route was not lethal although black, necrotic, ulcerating lesions were produced. Intranasal instillation of collagenase resulted in confluent pulmonary hemorrhage, while injections resulted in severe abdominal hemorrhage with foci on the peritoneal membrane and intestinal serosa. Intravenous injections elicited abdominal hemorrhage and petechial hemorrhage with focal necrosis of the lungs. The endotoxin from Pseudomonas aeruginosa C9 was obtained by five standard methods of extraction for comparative electron microscopic studies. Observation of the five preparations demonstrated the presence of two major types of structures. The first of these was seen in endotoxins prepared by trichloroacetic acid, ethyl ehter, hot water, and ethylenediaminetetraacetate-lysozyme extraction, and consisted of discrete spherules containing small spherules within and having a homogeneous staining center and rod-like border. The other morphologic type was seen only in preparations obtained by the aqueous phenol technique and consisted of pleomorphic staining material and rodlets.