Food Protection Trends - March/April 2021 - 192

Facility O used ozonated water to rinse fish. Ozone
in water can be used as an antimicrobial agent on food,
including seafood, in accordance with the regulations under
21 CFR Part 173.368.
DISCUSSION
Facilities N and O were found by FDA to have a higher
prevalence of L. monocytogenes (11 and 10 positives,
respectively). Facilities N and O were also found to have
several insanitation observations, such as uncontrolled
dripping condensate, cross-contamination, and an ineffective
or no environmental sampling program.
During the initial inspection, facility O had carts of
packaged finished product stored under cooling units that
were dripping condensation, a common source of Listeria.
Sanitation monitoring for the prevention of adulteration of
food, food packing material, and food contact surfaces by
condensate is required in 21 CFR 123.11 (b)(5). Corrective
actions need to ensure that no product enters commerce
that is either injurious to health or is otherwise adulterated,
in addition to correcting the cause of the problem (e.g.,
elimination of condensation, repair or maintenance of
condenser). The cooler was reorganized to prevent product
from being stored under the cooler unit where dripping
condensation was previously observed. However, although
moving product away from dripping condensate is an
acceptable immediate and preliminary correction, this
correction does not correct the cause of the uncontrolled
dripping condensate.
Facility O was found by FDA to have L. monocytogenes in
10 environmental samples in the initial inspection and in
eight environmental samples and finished product in the first
re-inspection. The environmental sampling results showed
that the firm had inadequate cleaning and sanitizing because
the step ladders used in the brining area to place fish on trays
into racks for the smoker that were found positive during
the initial inspection were still contaminated with L. monocytogenes in the first re-inspection. The PFGE conducted by
FDA showed that a resident strain of L. monocytogenes was
established in the facility and that L. monocytogenes isolated
from the finished product most likely occurred from crosscontamination within the facility. Although facility O had
several sanitation controls in place, it appears that the firm's
use of ozonated water on raw product and chemicals on
food contact surfaces and floors did not compensate for the
insanitary practices.
Facility O appeared to have an ineffective environmental
sampling plan. In view of FDA detecting 10 L. monocytogenes
positives in one sampling and the firm detecting only two
positives over a 10-month period, it appears that the firm's
environmental sampling was ineffective. Firms should
routinely examine their sampling frequency and timing
of collection along with the number and location of samples
collected.

192

Food Protection Trends March/April

Environmental sampling should be conducted to verify
the effectiveness of cleaning and sanitizing and to identify
and eliminate harborages of L. monocytogenes (15). L. monocytogenes may not be eliminated by routine sanitization
because it is capable of producing biofilms and persisting
in processing facilities by establishing harborages and
niches (3). Processors should sample after several hours
of production to allow harborages to loosen and L. monocytogenes to be dislodged (15). Sampling immediately
following cleaning and sanitizing can result in consistently
negative results and a failure to identify harborages (15).
Processors should also test environmental samples for the
presence of Listeria spp. Although L. monocytogenes is the
most concerning species of Listeria that causes human
illness, the presence of Listeria spp. is often used to identify
conditions conducive to the presence and growth of L. monocytogenes (3, 15). FDA's draft guidance for industry
" Control of Listeria monocytogenes in Ready-to-Eat Foods "
recommends that processors test environmental samples for
the presence of Listeria spp. without determining whether
L. monocytogenes is present (23). Testing for Listeria spp.
detects both L. monocytogenes and the more common
nonpathogenic species (15, 23). To ensure that Listeria
control measures eliminate harborages of Listeria, processors
should conduct robust environmental sampling with a " seek
and destroy " mentality (23). The draft guidance recommends
that processors determine the appropriate number of
sampling sites based on the size of the plant, plant features,
product flow, characteristics of the RTE food, the processing
methods used to produce the food, and any previous
sampling results. Even the smallest processors should collect
weekly samples after several hours of production from at
least five food contact surfaces and five nonfood contact
surfaces on each RTE production line of food that supports
the growth of L. monocytogenes (e.g., cold-smoked salmon).
Additionally, the draft guidance recommends that all food
contact surfaces be tested at least once each month and all
nonfood contact surfaces at least once each quarter. With
this amount of sampling, processors should expect to detect
Listeria spp. occasionally in a few environmental samples
and be ready with appropriate corrective actions based on
location.
Sampling food contact surfaces and taking appropriate
corrective actions is critical due to the risk of contaminating
food. During the initial inspection, facility O was found by
FDA to have L. monocytogenes on a food contact surface
(the bottom rack of a cart in the brine cooler holding
exposed salmon fillets on above racks). The firm's corrective
actions included cleaning and documentation of sanitation
improvements. When L. monocytogenes is detected on food
contact surfaces, such as racks, carts, utensils, brining tanks,
and cutting boards, FDA recommends that processors
implement corrective actions that address both the facility
and the food (23). Facility-related corrective actions should

Food Protection Trends - March/April 2021

Table of Contents for the Digital Edition of Food Protection Trends - March/April 2021