Highly selective medium for isolation of Listeria monocytogenes from food

Appl Environ Microbiol. 1990 Oct;56(10):3154-7. doi: 10.1128/aem.56.10.3154-3157.1990.

Abstract

A new selective medium (Al-Zoreky-Sandine listeria medium [ASLM]) was formulated to recover Listeria monocytogenes from food specimens; the medium completely inhibited common food microflora. Recognition of Listeria colonies is evident by black discoloration of the medium due to esculin hydrolysis without need for special illuminating equipment. The medium contains acriflavin, ceftazidime, and moxalactam as selective agents. Compared with Listeria Selective Agar, ASLM was equally effective in recovering L. monocytogenes. However, ASLM inhibited micrococci, enterococci, and gram-negative bacteria, especially a strain that mimicked L. monocytogenes on Listeria Selective Agar. The new medium was able to recover heat injured cells with only 15% less count than the nonselective medium.

Publication types

  • Comparative Study

MeSH terms

  • Bacteria / metabolism
  • Bacteriological Techniques*
  • Culture Media*
  • Esculin / metabolism
  • Food Contamination
  • Food Microbiology*
  • Hot Temperature
  • Listeria monocytogenes / isolation & purification*
  • Listeria monocytogenes / metabolism

Substances

  • Culture Media
  • Esculin