Studies on pyrogenic factors from Proteus vulgaris

Shaw, John A. M (1962) Studies on pyrogenic factors from Proteus vulgaris. PhD thesis, University of Glasgow.

Abstract

1. A survey has been made of the recent literature dealing with the chemical and biological properties of bacterial endotoxins. 2. The pyrogenic constituent present in the culture filtrate of Proteus vulgaris has been isolated as an antigenic protein-lipopolysaccharide complex, analogous to the 'S' somatic antigens of Gram-negative bacteria. 3. The lipopolysaccharide, N, 2.1; P,1.7, extracted from the isolated complex, or from the concentrated culture filtrate, by means of hot aqueous phenol, contained about 30% of a chloroform soluble lipid. It was soluble with difficulty in water and toxic in rabbits at doses of 20-40mug/kg. but much less toxic in mice (LD 50 850 mug.). The material possessed the immunological specificity of the protein-polysaccharide complex but was non-antigenic in inducing the formation of precipitins in rabbits; it was a powerful pyrogen, activate 0.005 ?g/kg. in rabbits. The sugar composition of the polysaccharide component and a preliminary analysis of the fatty acids of the lipid component are given 4. The lipopolysaccharide constituted 20-25% of the crude material extracted with phenol from the concentrated culture filtrate; the remaining 75-80% was obtained as two main fractions:- (a) a lipid-free weakly pyrogenic polysaccharide, N.5.9; F.0.4, soluble in 50% alcohol, giving amino acids on hydrolysis and containing the sugars glucose, mannose and glucosamine. It gave a precipitin reaction with immune sera prepared against the homologous organisms, distinguishable from that given by the lipopolysaccharide, and probably contained more than one component. (b) a lipid-free weakly pyrogenic polysaccharide N.3.4; P.0.9, precipitating along with the lipopolysaccharide at 50% alcohol concentration but remaining in the supernatant during fractional sedimentation at 20,000 g. The predominant reducing sugar found was mannose along with some glucose; glucosamine was present and several amino acids were obtained on hydrolysis. 5. The lipopolysaccharide obtained from the culture filtrate [LPS(E)] was compared with that obtained from cells of the same strain of Proteus vulgaris [LPS(E)]. Chemically they differed in the LPS(E) contained a trace of mannose which was absent from LPS(S) and the lipid from LPS(E) did not appear to contain arachidic acid and only a small amount stearic acid which were notably present in the lipid of LPS(S). Physically, LPS(E) was more difficult to dissolve in water. Pyrogenicity and toxicity in rabbits were similar with both materials but LPS(S) appeared more toxic to mice. Serological tests did not distinguish between the two substances. 6. The effect of various doses of the lipopolysaccharide, LPS(E), on the pyrogenic response in rabbits was investigated. Post-mortem findings following administration of lethal doses are recorded. 7. The construction of an apparatus for the photographic recording of the results of agar-diffusion precipitin tests is described (Appendix).

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Microbiology
• Date of Award: 1962
• Depositing User: Enlighten Team
• Unique ID: glathesis:1962-72903
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 11 Jun 2019 11:06
• Last Modified: 11 Jun 2019 11:06
• URI: https://theses.gla.ac.uk/id/eprint/72903