3.3. Efficacy of ListShield™ on smoked salmon obtained from a
production line/facility prior to packaging
The effect of ListShield™ was studied at a Scottish smoked
salmon production facility. Salmon fillets were obtained directly from the production line. Despite thorough disinfection and sanitation
of the production line one day prior to the experiment, 30%
(3 out of 10) of the smoked salmon fillets in the control group 1
(Fig. 3) were found to be contaminated with environmental (i.e.,
non-challenge strain) L. monocytogenes. Treatment with ListShield™
(group 2) resulted in 0% recovery of L. monocytogenes in
these fillets. Groups 3 and 4 were experimentally innoculated with
the challenge L. monocytogenes strain Lm376 in addition to any
L. monocytogenes strains that may have been naturally present on
the fillets. None of the fillets in the group treated with ListShield™
tested positive for L. monocytogenes; whereas 100% of the experimentally
innoculated and water-treated fillets were positive for
L. monocytogenes. In summary, both the experimental and natural
contamination of the smoked salmon fillets by L. monocytogenes
was reduced to undetectable levels after treatment with
ListShield™.