[Surface structure of the elementary bodies of Chlamydia]

The surface structure of chlamydial elementary bodies (strain PL-B577 causing enzootic abortion of ewes and strain CP-1 isolated from a patient with Reiter's syndrome), concentrated directly on the grid of an electron microscope, was studied by the method of negative staining. The surface of the cell wall of chlamydial elementary bodies in the preparations of crude cultures, not subjected to enzymatic purification, was formed by spherical subunits 4 nm in diameter. The surface of the cell wall of elementary bodies was found to have projections 10-20 nm long and 3-4 nm in diameter, as well as annular structures 15-22 nm in diameter in hexagonal arrangement, spaced at 45 nm and probably traversed by these projections. The number of such structures in a group was 12-15. These data correspond to the model representing the structure of the surface of chlamydiae, which was proposed by Matsumoto in 1979.