title: Ultrastucture of the surface of Rickettsia prowazeki and Rickettsia akari.
abstract: Negative-contrast electron microscopy revealed that the outer layer of the envelope of rickettsiae is composed of a matrix of tetragonally arranged subunits. The layer projects approximately 7 nm from the cell wall. It is suggested that this outer layer is analogous to the structure considered capsule-like in morphology.
mesh_terms: D000942:Antigens, Bacterial; D002473:Cell Wall / Q000276:immunology / Q000648:ultrastructure; D008854:Microscopy, Electron; D010772:Phosphotungstic Acid; D012281:Rickettsia / Q000276:immunology / Q000648:ultrastructure*; D012283:Rickettsia prowazekii / Q000276:immunology / Q000648:ultrastructure*; D013194:Staining and Labeling
chemical_list: D000942:Antigens, Bacterial; D010772:Phosphotungstic Acid