Media for Mycobacteria

AMERICAN TRUDEAU SOCIETY MEDIUM 

• Egg-based
• Purpose – isolation of M. tuberculosis
• Component: 
  • Eggs – provides fatty acid 
  • Potatoes – carbon source 
  • Malachite green – inhibitor

LOWENSTEIN-JENSEN MEDIUM

• Purpose – for cultivation of Mycobacterium spp.
• Component: 
  
  • Potato flour 
  • Egg 
  • Glycerol 
  • Asparagine – for max. production of niacin by certain Mycobacterium spp. 
  • Malachite green – inhibitor

MODIFICATIONS 

LJ medium w/ 5% NaCl – to aid in identifying rapid growers 

Gruft modification – more selective

• Components: 
  
  • Selective agents 
    
    • Penicillin (50 U/ml) 
    • Nalidixic acid (35 ug/ mL) 
  • Ribonucleic acid (0.05 ug/ml) 
    
    • Increases rate of mycobacterium isolation

Petran and Vera modification – permits gentler decontamination or digestion procedures

• Components: 
  
  • Selective agents (added) 
    
    • Cyclohexamide 
    • Lincomycin 
    • Nalidixic acid MIDDLEBROOK 7H10 & 7H11

AGARS Purpose – used to cultivate Mycobacterium spp.

NOTE: Isoniazid-resistant strains grows better in this medium

Components (7H11) 

• Casein hydrolysate – stimulates growth of drug- resistant Mycobacterium tuberculosis Components

(Both) 

• Oleic-acid-dextrose-catalase (OADC) –simulates egg components 
  
  • Oleic acid– fatty acid used by mycobacteria 
  • Dextrose – for energy production 
  • Catalase – neutralize toxic peroxidase 
• Albumin – inhibits toxic agents; source of CHON 
• Malachite green – inhibitor

MITCHISON 7H11 SELECTIVE AGAR

• Component:
  
  • Inhibitors:
    
    • Amphotericin B
    • Carbenicillin
    • Polymyxin B
    • Trimethoprim