Viable but non-culturable Listeria monocytogenes on parsley leaves and absence of recovery to a culturable state
2007
Dreux, Nicolas | Albagnac, Guy | Federighi, Michel, M. | Carlin, Frederic, F. | Morris, Cindy E. | Nguyen The, Christophe, C. | Sécurité et Qualité des Produits d'Origine Végétale (SQPOV) ; Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | SECurité des ALIments et Microbiologie ; Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Vétérinaire de Nantes-École nationale d'ingénieurs des techniques des industries agricoles et alimentaires (ENITIAA)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS) | Unité de Pathologie Végétale (PV) ; Institut National de la Recherche Agronomique (INRA)
International audience
显示更多 [+] 显示较少 [-]英语. To investigate the presence of viable but non-culturable Listeria monocytogenes during survival on parsley leaves under low relative humidity (RH) and to evaluate the ability of L. monocytogenes to recover from VBNC to culturable state under satured humidity. Methods and Results: Under low RH (47–69%) on parsley leaves, the initial number of L. monocytogenes populations counted on non selective media (109 L. monocytogenes per leaf on TSA) was reduced by 6 log10 scales in 15 days, whereas number of viable L. monocytogenes counted under the microscope was reduced by 3–4 log10 scales, indicating the presence of VBNC cells. This was demonstrated on three L. monocytogenes strains (EGDe, Bug 1995 and LmP60). Changing from low to 100% RH permitted an increase of the culturable counts of L. monocytogenes and this growth was observed only when residual culturable cells were present. Moreover, VBNC L. monocytogenes inoculated on parsley leaves did not become culturable after incubation under 100% RH. Conclusions: Dry conditions induced VBNC L. monocytogenes on parsley leaves but these VBNC were likely unable to recover culturability after transfer to satured humidity.
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