Ans. c (Giemsa stain).(Ref. Textbook of microbiology by Ananthanarayan 6th ed. 389)Chlamydiae# Chlamydiae cannot make their own ATP. They are obligate intracellular parasites that cause mucosal infections. The chlamydial cell wall is unusual in that it lacks muramic acid.# C. pneumoniae and C. psittaci cause atypical pneumonia; transmitted by aerosol.# Chlamydia trachomatis causes reactive arthritis, conjunctivitis, nongonococcal urethritis, and pelvic inflammatory disease (PID). Types A, B, and C--chronic infection, cause blindness in Africa. Types D-K--urethritis/PID, ectopic pregnancy, neonatal pneumonia, or neonatal conjunctivitis. Types LI, L2, and L3--lymphogranuloma venereum (acute lymphadenitis--positive Frei test).# Lab diagnosis: cytoplasmic inclusions (HP bodies) seen on Giemsa or fluorescent antibody-stained smear.# Treatment: erythromycin or tetracycline.2 forms:# Elementary body (small, dense), which Enters cell via endocytosis# Initial or Reticulate body, which Replicates in cell by fission.STAINFORFontana-Tribondeau stainA method of staining spirochetes by silver impregnation, using ammoniacal silver nitrate solution (tannine + AgNO3 in NH3).Carbol fuchsin stainA stain for microorganisms containing basic fuchsin with dilute phenol as a mordant. It is also used as a counterstain for Legionella pneumophila following other routine stains. Stained cells appear pink to red.Giemsa staina solution containing azure ll-eosin, azure II, glycerin, and methanol.Uses:1. Differential staining of blood smears, spleen, and bone marrow cells.2. For staining protozoan parasites such as Plasmodium spp. and Trypanosoma spp.,3. For Chlamydia spp. as well as Borrelia.4. For the identification of viral inclusion bodies.The stained nuclei and chromosomes may vary in color from reddish-blue to purple to pink.Reverse (R) Giemsa methoda method in which the reciprocal (R-bands) of the banding pattern seen in the Giemsa method for chromosomes is obtained.Also remember:The spirochetes are spiral-shaped bacteria with axial filaments and include Borrelia (big size), Leptospira, and Treponema. Only Borrelia can be visualized using aniline dyes (Wright's or Giemsa stain) in light microscopy. Treponema is visualized by dark-field microscopy.