Further structural characteristics of the lipopolysaccharide from Coxiella burnetii strain Nine Mile in low virulent phase II

摘要

Coxiella burnetii, an obligatory intra-phagolysosomal parasiting bacterium is the causative agent of Q fever. The bacterium is unique among Rickettsiae in that it undergoes a virulent phase I to low-virulent phase II variation upon serial laboratory passages in embryonated hen eggs. A lopopolysaccharide (LPS) belonging to the main components of the C. burnetii outer membrane has important biological properties. It has been shown that whereas the phase I cells express a smooth (S) LPS I with Opolysaccharide chain, the phase II cells express a rough (R) LPS II. Chemical composition and structure of the lipid A-proximal carbohydrate region of LPS II have been established from the results of methylation analysis fast atom bombardment and electrospray ionization mass sectrometries. Nevertheless, some authors still refer to a paper in which glucose has been reported as an integral constituent of LPS II.