Anaerobic culture media for anaerobic bacteriology

Media used in the anaerobic bacteriology can be freshly prepared or  purchased from commercial suppliers.   Media for anaerobic culture prepared in the laboratory should be used within 2 weeks of preparation as long storage degrades the quality of the media due to peroxides accumulation and dehydration.  Anaerobic culture media contains reducing agents such as cysteine.

Pre-reduced, anaerobically sterilized media are produced by different commercial suppliers, which have extended shelf life of up to six months. The primary plating media for inoculating anaerobic specimen includes a non-selective blood agar and one or all of the following mentioned selective media.

Non selective media used in anaerobic bacteriology:

  1. Cooked meat broth (e.g. Robertson’s Cooked Meat Medium): Non-selective for cultivation of anaerobic organisms; with addition of glucose, can be used for gas-liquid chromatography.
  2. Anaerobic blood agar: It is a non-selective medium for isolation of anaerobes and facultative anaerobes.
  3. Egg-yolk agar (EYA): Non-selective for determination of lecithinase and lipase production by Clostridia and Fusobacteria.
  4. Peptone-yeast extract glucose broth (PYG): Non-selective for cultivation of anaerobic bacteria for gas-liquid chromatography.

Selective and differential media used in anaerobic bacteriology:

  1. Bacterioides bile esculin agar (BBE): It is selective and differential for Bacteriodes fragilis group and good for presumptive identification.
  2. Laked Kanamycin-vancomycin blood agar (LKV): It is selective for isolation of Prevotella and Bacteriodes spp.
  3. Anaerobic phenylethyl alcohol agar (PEA): Selective for inhibition of gram negative rods and swarming by some Clostridia.
  4. Cycloserine cefoxitin fructose agar (CCFA):  selective for Clostridium difficile.
  5. Thioglycollate broth: Non selective for cultivation of anaerobes; as well as facultative anaerobes and aerobes.