the production of safe food (Tompkin, 2002). Many modern laboratory
techniques can be applied to allow refinement of elements
of the L. monocytogenes control strategy, yet these are often
ignored by the food industry, as they are not necessary to comply
with regulatory requirements. Traditional ISO detection protocols
are commonly used to monitor the presence of L. monocytogenes
in food products and the production environment: however while
this can identify contamination hotspots, it does not lend itself to
understanding issues such as tracking contamination routes, or
identifying more problematic persistent isolates. Supplementing
traditional detection data with sub-typing techniques such as
pulsed-field gel electrophoresis (PFGE) can facilitate this type of
scrutiny. Another aspect of pathogen control that is often not
addressed concerns the efficacy of sanitizers used at a production
site. These are applied to control L. monocytogenes and of bacteria
of concern to public health. In particular these sanitizers are used
to target in-house strains, some of which may persist at the facility,
for long periods of time. Marrying these types of analyses to
the standard monitoring program has advantages: it can help
pinpoint a breakdown in the control of the bacterium by identifying
vectors responsible for its introduction or transfer through
the production facility, identify ineffective sanitizers being used,
identify problematic persistent isolates, and their sources, and
ultimately reduce the risk to food safety and its impact on public
health.
This study describes the use of a valid paradigm including
ingredient sampling, PFGE sub-typing, and high-throughput sanitizer
screening against a selection of in-house Listeria isolates, in
combination with targeted and routine sampling, that is designed
to improve the control of L. monocytogenes at a poultry production
facility.