If you think about it, you'll notice that extracellular bodies/organisms can be seen in cultures more readily than intracellular ones. Examples: rickettsiae (obligate intracellular) & legionella (facilitative intracellular) are not readily visualized on gram stain. The same applies to reticulate bodies.The elementary body which is extracellular is the one to see in tissue culture???
Arrgh, thats really confusing!