- Written cleaning and sanitizing proce-
dures should be developed and posted
for each area in the plant. - Environmental sampling programs to
verify the effectiveness of cleaning and
sanitizing should be established.
Verification of L. monocytogenes Control
- A microbial assay of weekly samples
from plant areas, equipment, and the
air supply should be conducted. It is
especially important to sample points
between the kill step and packaging. - Samples can be composited to reduce
the analysis cost. If a composite sample
is positive, a follow-up analysis of indi-
vidual samples is necessary to determine
which equipment is the contamination
source.
The following important suggestions for
Listeria control in meat plants should be
considered: - Mechanically or manually scrub floors
and drains daily. Drains should contain
a “quat plug” or be rinsed with disin-
fectants daily. - Clean the exterior of all equipment,
light fixtures, sills and ledges, piping,
vents, and other areas in the processing
and packaging areas that are not in the
daily cleaning program. - Clean cooling and heating units and
ducts weekly. - Caulk all cracks in walls, ceilings, and
window sills. - Keep hallways and passageways that
are common to raw and finished prod-
uct clean and dry. - Minimize traffic in and out of pro-
cessing and packaging areas and
establish plant traffic patterns to
reduce cross-contamination from feet,
containers, pallet jacks, pallets, and
fork trucks. - Change outer clothing and sanitize
hands or gloves when moving from a
“raw” to a finished product area. - Change into clean work clothes daily.
Provide some pattern of color-coding
to designate various plant areas. - Minimize the number of visitors and
require them to change into clean
clothes provided at the plant. - Provide a plant environmental moni-
toring program to measure effective-
ness of the Listeriacontrol procedures. - Enclose processing and packaging
rooms so that filtered air comes in and
ensure that these areas are under pos-
itive pressure. - Clean and sanitize all equipment and
containers before their entry into pro-
cessing and packaging areas.
Three alternative levels (Lazar, 2004) of
Listeria control in a plant are:
Alternative Level 3—basic control level
addressed through effective sanitation
Alternative Level 2—effective sanitation is
combined with post-lethality treatments such
as heat, antimicrobial agents, or freezing
Alternative Level 1—effective sanitation,
antimicrobial treatment, and a post-lethality
treatment combining all three strategies
It has been suggested (Russell, 2003) that
28% of cattle designated for harvesting are
infected with Escherichia coliO157:H7 and
that an average of 43% of beef carcasses
contain this pathogen at various stages of
production.
In September 2002, the U.S. Department
of Agriculture’s Food Safety and Inspection
Service (USDA, FSIS) announced its plan to
institute a series of additional measures to
complement previous policies aimed at the
prevention and control ofE. coliin ground
beef. These included: - All beef harvesting and grinding plants
are required to acknowledge that E. coli
Meat and Poultry Plant Sanitation 305