Attempts at demonstration of lipopolysaccharide in phase II Coxiella burnetii

Comparison of some properties of phase I and phase II Coxiella burnetii cells suggests the presence of lipopolysaccharide (LPS) also in the surface structures of phase II cells. Polysaccharide chains were released from them by mild acid hydrolysis and corpuscular residues resulting from such hydrolysis elicited in rabbits anti-lipid A-antibodies. Toxicity for adrenalectomized and actinomycin D-sensitized mice was demonstrated with phase I cells, but not with much higher concentrations of phase II cells. By contrast, the extent of protection against formation of ascitic tumour in mice with comparable concentrations of phase I and phase II cells was similar.