A laboratory receives sputum samples suspected to contain Mycobacterium tuberculosis. Which culture medium is the standard solid medium used, and what is its key constituent?
- A LJ medium containing egg and glycerol with malachite green ✓
- B Chocolate agar enriched with X and V factors
- C Selenite F broth containing sodium selenite
- D TCBS agar containing sucrose and bromothymol blue
Correct answer: A. LJ medium containing egg and glycerol with malachite green
Explanation
Lowenstein-Jensen medium is the conventional solid medium for M. tuberculosis. It contains coagulated egg, glycerol as a carbon source, and malachite green which suppresses contaminating flora during the long incubation. Chocolate agar is for Haemophilus and Neisseria, selenite F is an enrichment broth for stool pathogens, and TCBS isolates Vibrio species.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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