Chlamydia sp. Colored transmission electron micrograph (TEM) of Chlamydia sp. bacteria. The cell contents of these bacteria are colored purple. They are spherical, Gram-negative bacteria that are obligate intracellular parasites. Chlamydia sp. cause the sexually transmitted disease lymphogranuloma venereum and eye diseases trachoma and inclusion conjunctivitis (TRIC). Chlamydia also causes non specific urethritis, otitis media and cervicitis. Treatment for diseases caused by Chlamydia sp. involves taking either erythromycin or tetracycline antibiotic drugs. Magnification: unknown.