Biomedical Engineering Reference
In-Depth Information
The slicer harboring persistent
L. monocytogenes
is a more concerning scenario, as
all products handled on the slider may become contaminated. Persistent contamina-
tion may indicate inadequate equipment maintenance, poor equipment design, or
ineffective sanitation processes.
Transferring bacteria from fl oors and drain covers to FCS was not detected in a
mock deli (Maitland et al.
2013
). This study was limited to a group of volunteers
without previous food service experience working in a controlled environment for a
brief period of time. From practical experience, we are concerned about scenarios
such as untied shoe laces dragging on the fl oor, dropped utensils, or customer-
interrupted trash clean-up, which may require inadvertent employee contact with
fl oors or drains creating opportunities for NFCS to FCS transmission not observed
in the mock deli environment. In our most recent study, we found the same DNA
fi ngerprint from
L. monocytogenes
isolated from the fl oor and from FCS (
Simmons
et al. unpublished
). While these studies cannot determine the direction of transfer
(e.g., from the drain to the sink or from the sink to the drain), it underscores that this
pathogen can be transmitted throughout the deli environment and that control strate-
gies are critical to prevent it from contaminating foods.
5.4
Control Strategies to Eliminate
L. monocytogenes
and Prevent Listeriosis
Preventing listeriosis from foods handled at retail is a complex process and diffi cult
to measure. The fi rst step is full cooperation and participation in food recalls. RTE
foods are routinely tested by manufacturers and regulatory agencies, and those that
are contaminated with
L. monocytogenes
are recalled to remove them from the mar-
ket to ensure public safety. However, deli personnel must understand that RTE prod-
ucts processed (e.g. sliced, re-portioned, or packaged) at retail are at risk for
cross-contamination in stores and manufacturing-based controls alone are not
enough to prevent all listeriosis cases. The 2013 US Interagency Retail
L. monocy-
togenes
Risk Assessment Workgroup recommended fi ve targets for reducing the
risk of listeriosis from retail foods: (1) control growth through the use of growth
inhibitors in products and temperature control during storage; (2) control
cross-contamination during routine deli operations; (3) control contamination at its
source: incoming products, the environment, or niches; (4) continue sanitation to
eliminate
L. monocytogenes
from the environment; (5) identify key routes of con-
tamination to RTE foods, such as the slicer (deli meats and cheeses) or serving
utensils (deli salad) (USDA-FSIS and FDA
2013
).
Business managers and merchandizers determine which products will be sold
(RTE meats with or without growth inhibitors; pasteurized or unpasteurized
cheeses), the number of labor hours allocated to sanitation, which chemicals are
used, and many other factors which can impact upon the safety of retail products
and prevalence and persistence of
L. monocytogenes
. However, immediate supervi-
sors and managers drive the quality of food safety practices more than any other
