Pyogenic coccus Medically Important Bacteria Lacking Rigid cell wall Flexible cell walls (Spirochetes) Borrelia MycopLasma ureaplasma Simple unicellular Filamentous Actinomyces Nocardia Obligate intracellular Free-living parasite Chlamydia Coniella Ehrlichia Gram-positive Gram-negativePyogenic coccus