The possibility that long term in vitro chilled storage may result in sub-lethal damage to Listeria monocytogenes cells was investigated by comparing growth of chill-stored (starvation at 4 °C) and fresh cultures on selective and non-selective media.
Growth of freshly grown cells was minimally (3-8%) affected by selective LSAMM agar compared with non-selective Brain Heart Infusion agar.
In contrast, numbers of chill-stored strains were reduced by greater than 99% after direct plating on the same selective and non-selective media.
Furthermore, chill-stored strains were able to grow in standard selective broth (Listeria Selective broth and Fraser broth) only if undiluted inocula (approximately 105-106 cfu ml-1) were used, whereas they were capable of growth in Brain Heart Infusion broth even when the lowest dilutions were used (approximately 101 cfu ml-1).
The potential public health consequences of this finding for the isolation of Listeria monocytogenes from foods is considered.
Mots-clés Pascal : Etude comparative, Listeria monocytogenes, Bactérie, Conservation, Réfrigération, Multiplication microorganisme, Méthode analyse, Essai normalisé, Endommagement, Pathogène
Mots-clés Pascal anglais : Comparative study, Listeria monocytogenes, Bacteria, Conservation, Refrigeration, Microorganism growth, Analysis method, Standard test, Damaging, Pathogenic
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0200690
Code Inist : 002A35D. Création : 16/11/1999.