THE USE OF POTASSIUM TELLURITE, SODIUM AZIDE, AND ACETIC ACID IN A SELECTIVE MEDIUM FOR THE ISOLATION OF LISTERIA MONOCYTOGENES

Abstract

Sodium azide added to tryptose agar in concn. of 0.2%, 0.1%, 0.5% and 0.03% was found to be unsatisfactory for use as a selective media to be used for isolation of L. monocytogenes. K tellurite at a concn. of 0.05%, in either tryptose agar or nutrient broth, was effective for isolation of L. monocytogenes from either artificially or naturally contaminated material containing this bacterium. A deep brain medium containing acetic acid in concns. of 0.01%, 0.15%, 0.1%, 0.5% and 10% was also found to be effective in the higher concns. However, the K tellurite media are favored because of their ease of prepn.