Transcript Smoked Fish Consortium June 5th & 6th, 2001

Listeria Monitoring & Testing
in RTE seafood plants
What to test, how to test, &
how to take appropriate action
Goal of Listeria testing and
monitoring testing program is
to FIND Listeria
Listeria testing provides an opportunity to
identify problems before they lead to
finished product contamination, recalls, &
regulatory actions
What to test?
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Raw materials
Finished Products
Processing plant environment (all areas
including raw, in-process, and finished
product areas)
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Food contact surfaces
Non-food contact surfaces
What to test for?
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Listeria monocytogenes
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The specific type (species) of Listeria that
can cause human disease
Listeria species
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Includes different species of Listeria, such
as Listeria monocytogenes as well as
Listeria innocua and others, which do not
cause human disease
Why test for Listeria
monocytogenes?
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It is the specific type that causes human
disease
Listeria monocytogenes specific testing is
generally conducted when finished products
are tested since only L. monocytogenes is
considered an adulterant
Listeria testing may not always be a good
indicator for presence of L. monocytogenes
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Sometimes only 5-10% of Listeria species positive
samples harbor L. monocytogenes
Why test for Listeria species
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More common than Listeria monocytogenes,
thus more appropriate for routine monitoring
Test results may be available more rapidly
than for Listeria monocytogenes
Testing may be cheaper than Listeria
monocytogenes testing
Listeria species testing generally used for
environmental samples
Raw material testing
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May be important for raw materials to
be used for cold smoking, which is a
process that does not kill Listeria
May be used to test raw materials from
new suppliers
May be used to continuously monitor
raw materials from suppliers
Finished product testing
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Finished product testing is NOT an essential part
of a L. monocytogenes control program
Sometimes conducted at request of customers
Finished product testing requires specific
definition of lots:
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L. monocytogenes positive lots in commerce have to
be recalled
In a test and hold program (which is recommended),
L. monocytogenes positive lots have to be
reprocessed or destroyed
Environmental Listeria testing
An essential part of each Listeria
control program
Why environmental Listeria
testing and monitoring?
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Finished product contamination can most
commonly be traced back to Listeria found in
the processing environment
Finding of environmental samples positive for
Listeria does not require product recall
Regulatory agencies are developing directives
and guidance encouraging regular
environmental Listeria testing
Goals of an environmental
Listeria testing program
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Identify problem areas harboring
Listeria and locate contamination
sources
Confirm effectiveness of problemsolving procedures
Critical considerations for environmental Listeria monitoring program
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Design of environmental testing
program
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When to test (before start-up; mid-shift;
end of shift?)
Where to test (product contact surfaces,
cart wheels, drains?)
How often to test (weekly, monthly?)
Response to a positive sample
Environmental Listeria
monitoring plan
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Each environmental monitoring plan
should be specific to the individual
processing facility.
Listeria spp. testing is recommended for
non-product and product contact
surfaces
Where to test?
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Food contact surfaces
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Food contact surface positives may have to be
followed up with finished product testing
Non-food contact surfaces
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Sites in coolers (floors, walls, cooler coils,
condensate collectors etc.)
Tubs, conveyances, underneath tables
Floors, floor mats, walls, & drains in production
areas
Testing of non-food contact
surfaces
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Initial weekly sampling is recommended
for most wet areas where Listeria can
grow
Some sampling sites should be constant
(i.e., same site should be sampled
regularly), but others can vary
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Additional samples may need to be taken in
proximity of positive samples
Where to test – the zone
concept
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Plant is divided into different zones; zones are defined
based on relative potential for finished product
contamination a site or area represents; sampling and
corrections triggered by positive samples differ by
zones.
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Zone 1: Finished product contact surfaces
Zone 2: Non-food contact surfaces in finished product area
Zone 3: Product contact surfaces in raw product handling
areas
Zone 4: Areas remote from finished product handling (e.g.,
non-product contact surfaces in the raw product handling
areas)
When to test?
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Pre-op
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Less likely to yield positive samples
More easy to interpret, will identify
sanitation weaknesses
Mid-op
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More likely to yield positive
Will provide information on spread of
Listeria during processing
What to do with testing results
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Review testing results every time results
are reported
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This should include review of last 4-8
sampling results to identify trends (e.g.,
site that has positives with intervening
negatives
Take corrections on each positive sample
and document action
What to do with testing results
(cont’d)
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Organize testing results in one location
(folder, three-ring binder)
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Include documentation of corrections in
same location
Conduct regular (quarterly, yearly;
depends on testing frequency &
volume) review of testing results
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Tabulate and evaluate long-term trends
Guidelines for corrective
actions
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Corrections based on positive samples
need to be plant specific
Each positive sample should be followed
up with additional investigations
Trend towards increased frequency of
Listeria spp. needs to be investigated to
determine reason and action needs to
be taken to reduce frequency
Guidelines for corrective
actions (cont’d)
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Additional samples should be taken from
environmental area that showed positive
results
Additional positive samples after corrections
need follow up with intensified cleaning and
re-testing
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Problems areas may have to be shut down
temporarily
Consider if a test and hold program is needed
How is environmental testing
performed?
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Sponges are used to collect samples from
selected environmental sites
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Kits for sterile sample collection are available from
testing laboratories
Hands-on training in proper sampling technique should
be performed by professional
Environmental samples should represent constant
areas (e.g., 2 x 2 ft)
Product contact surface samples should be collected
from areas as large as possible
How is environmental testing
performed? (cont’d)
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After sample collection, sponge is deposited
in sterile plastic bag and sealed
Sponges are sent to laboratory for testing
Example of Listeria
Monitoring Plan
Example – Medium sized plant producing hot & cold smoked products
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Plant only tests environmental samples
(non-product contact surfaces and
product contact surfaces)
All testing is for Listeria spp.
Testing plan
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Samples from 10 non-food contact surfaces are
tested weekly; samples taken before production
starts
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6 sites in finished product area (1 floor sample near
slicer; 1 sample from underneath tables used for
product packaging, 2 employee contact surfaces, 1
floor drain, 1 sample from cart wheels
4 sites in raw material handling area (1 raw material
cooler floor, 1 brining cooler floor, 1 floor drain, 1
underneath table used for raw material prep)
Testing plan (cont’d)
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Samples from 5 product contact surfaces are
tested weekly; samples taken at least 3 h after
production started
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1 sample from
1 sample from
packaging
1 sample from
1 sample from
1 sample from
products
blade of slicing machine
scale used to weigh product before
skinning machine conveyer belt
trimming knife
totes used to move cold-smoked
Corrections – non-product
contact surfaces
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Raw material sites with positive results for 2
consecutive weeks will receive more stringent
cleaning and sanitizer rotation until at least 3 of 4
consecutive tests are negative
Finished product area sites with a positive result
will receive immediate attention and re-testing.
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If re-test is positive line may be shut down (or go to
test and hold procedure for finished products) and
additional cleaning and sanitizing, including line
disassembly will be implemented until three
consecutive daily samples are negative.
Corrections – product contact
surfaces
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Sites with a positive result will receive immediate
intensified cleaning and sanitizing, as well as daily
sampling. If 2 consecutive samples are positive
the area is shut down and extensive sanitation
procedures are implemented. Swabs are taken
before start-up and at two-hour intervals until 3
consecutive negative samples demonstrate that
the contamination source has been eliminated; at
that point routine testing can be resumed.
Summary
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Listeria testing plan may include raw and
finished product testing
Environmental Listeria testing is necessary
to control this pathogen
Testing plant needs to be developed
individually for each operation
Positive testing results need to be followed
up with corrections, which need to be
documented