AN IMPROVED SELECTIVE AND DIAGNOSTIC MEDIUM FOR ISOLATION AND COUNTING OF LISTERIA SPP IN HEAVILY CONTAMINATED FOODS

Columbia agar base containing 0-001% acriflavine, 1-5% lithium chloride, 0-25% phenyl ethanol, 0-05% aesculin, 0057,) ferrous salt, 1% mannitol, 2-5% egg yolk emulsion and 0-008% phenol red (ALPAMY), recovered Listeria monocytogenes and some strains of Listeria seeligeri quantitatively, but suppressed Listeria ivanovii and virtually all other bacteria common in fresh foods. When used with foods processed for safety, repair on non-selective buffered glucose tryptone soya peptone yeast extract catalase agar must precede the use of ALPAMY. © 1988 Oxford University Press. All rights reserved.