Different sugar compositions of lipopolysaccharides isolated from phase I and pure phase II cells of Coxiella burnetii

Abstract

The compositions of lipopolysaccharides I and II, isolated from Coxiella burnetii phase I and pure phase II cells, respectively, showed drastic and clear-cut differences. Lipopolysaccharide II exhibited a comparatively simple composition. It contained, in addition to glucosamine (from lipid A) and a 2-keto-3-deoxyoctulosonic acid-related, thiobarbituric acid-positive substance, only two aldoses in high amounts, namely D-mannose and D-glycero-D-mannoheptose. Lipopolysaccharide I contained the same components, but it also contained at least eight other constituents including neutral sugars, e.g., an unusual branched sugar (3-C-methyl-6-deoxy-hexose) and unusual aminohexoses. Some components were characterized by a very high retention time in gas-liquid chromatography. The similarity of the phase variation in C. burnetii to the well-known smooth-to-rough mutation found in Enterobacteriaceae is discussed. Cells of phase I correspond to enterobacterial smooth forms, whereas cells of phase II might be compared to the rough forms.