Evidence for the existence of endotoxic activity in three strains of Moraxella.

The phenol extraction technique was used to obtain material with endotoxic activityfrom three strains of Moraxella. This material was subjected to partial purification. Biological activity was determined by inoculation of the extracts into the skinof rabbits, and noting the resultant skin reactions. Although containing some cellular contaminants such as nucleic acid from the extraction procedure, the endotin preparations showed biological activity in the microgram range. Killed but unextracted cellsalso elicited skil reactions when injected intradermally into the rabbit. A partial analysis of the biochemical components of the endotoxin revealed that these three strains contain endotoxin whose composition is similar in several respects to that of the endotoxins of the neisseriae and some of the enteric bacteria.