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Environmental Listeria Testing and Molecular Subtyping to Control Listeria monocytogenes in RTE Food Processing Environments



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Table of Contents

Environmental Listeria testing and molecular subtyping to control Listeria monocytogenes in RTE food processing environments

Transmission and pathogenesis of L. mono-cytogenes and other foodborne diseases

Listeria monocytogenes

Human listeriosis cases - Three General Scenarios

Environmental Listeria testing

Pilot study #1   Application of molecular subtyping to track L. monocytogenes contamination contamination RTE processing plants

Typing methods used

Examples of different L. monocytogenes ribotypes

Subtyping results - Plant I

Subtyping results - Plant II

Subtyping results - Plant II (Continued)

Ecology of L. monocytogenes in RTE processing plants

Ribotypes: Distribution analysis

Pilot study #2:  Tracking to determine sources of persistent L. monocytogenes contamination in RTE processing plants

In-Plant Listeria Contamination Patterns

Distribution of L. monocytogenes by sampling sites

Persistent L. monocytogenes environmental contamination

Pilot study #3:  Relationships between environmental L. monocytogenes and Listeria testing results

Listeria spp. and L. monocytogenes detection



Personal remarks

Molecular subtyping and the food industry - a vision

Research hypotheses

Host specificity and virulence differences among L. monocytogenes strains

Clonal Structure of L. monocytogenes

Selected Preliminary Results


Author: Martin Wiedmann
              Department of Food Science
              Cornell University
              Ithaca, NY 14853
              Phone: 607-254-2838
              Fax: 607-254-4868


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Last modified: June 24, 2002