Structural features of lipopolysaccharide from Rickettsia typhi: the causative agent of endemic typhus.

Rickettsia typhi causes endemic typhus, a relatively mild, acute febrile illness characterized by headache and macular rash. It is maintained in rodents and transmitted to humans by flea Xenopsylla cheopis. R. typhi contains a lipopolysaccharide thought to display a noticeable antigenic activity. We examined its structural features and it appears that the O-specific chain of the R. typhi LPS is composed mainly of the alternating Glc and QuiNAc residues linked by 1-->4 bonds.