[Livingontheland] FDA Approval of Listeria-specific Bacteriophage Preparation

TradingPostPaul tradingpost at riseup.net
Fri Sep 8 14:06:57 EDT 2006

gee - must be a lot of people getting sick from hot dogs and lunch meat,
... NOT

paul tradingpost at lobo.net

FDA Approval of Listeria-specific Bacteriophage Preparation
on Ready-to-Eat (RTE) Meat and Poultry Products

    In the Federal Register of August 18, 2006, FDA announced that it had
approved the use of a bacteriophage preparation made from six individually
purified phages to be used on RTE meat and poultry products as an
antimicrobial agent against Listeria monocytogenes. The rule is in response
to a food additive petition submitted in 2002 from Intralytix, Inc. 

Questions & Answers
1. What is a bacteriophage?

Bacteriophages (phages) are viruses that infect only bacteria and do not
infect mammalian or plant cells. Phages are ubiquitous in the environment,
and humans are routinely exposed to them at high levels through food and
water without adverse effect.
2. What is the additive that was approved?

The additive that was approved is a mixture of equal proportions of six
phages specific against L. monocytogenes. The petitioner's rationale for
incorporating six phages in one formulation is to minimize the possibility
of L. monocytogenes developing resistance to the additive. The approved
phage preparation is reported to be effective against 170 strains of L.
3. How is the bacteriophage used in the additive produced?

The phage is cultured using L. monocytogenes as the host organism. Because
the phage infects and destroys the host organism during its life cycle, the
final product does not contain any viable Listeria. In addition, because of
the purification steps that are used in making the phage, any toxic
components from the host organism are effectively removed from the final
phage product. To ensure safety, the regulation specifies that the additive
must test negative for L. monocytogenes, and the L. monocytogenes toxin,
listeriolysn O, must not be present at detectable levels, where the limit
of detection is 5 hemolytic units per ml.
4. What is the purpose of the additive?

The phage preparation will be used in meat and poultry processing plants
for spray application to the surface of RTE meat and poultry products, such
as lunch meats and hot dogs, to kill Listeria. The phage preparation will
be applied to the surface of RTE meat and poultry products at a level not
to exceed 1 ml per 500 cm2 food surface just prior to packaging. These
foods can become contaminated with Listeria during production, but unlike
fresh meat and poultry, these foods are consumed without additional cooking
that would kill the bacteria, thereby increasing the risk to Listeriosis,
an infection caused by the bacteria. Furthermore, L. monocytogenes is
capable of multiplying at low temperatures, so it can multiply in food over
time even when the food is kept in the refrigerator. Persons with increased
risk to Listeriosis are pregnant women, newborns, those with a compromised
immune system, and the elderly.
5. Is this additive novel?

This is the first time FDA has regulated the use of a phage preparation as
a food additive. However, phages are currently approved in the U.S. for
pesticide applications, including uses on crops. Although not currently
permitted in the U.S., phages are used in other countries in antibiotic
6. What was the basis of FDA's safety decision?

To support the safety of the proposed use of the Listeria-specific phage
preparation, the petitioner submitted published reports from animal studies
and results from the use of phages as therapies in the treatment and
prevention of infections in humans caused by bacteria. Based on this and
other information, FDA concluded that the additive does not pose any safety
concerns, providing that it complies with the identity and specifications
in the regulation.
7. What was the process of deciding that the phage was suitable for use in
meat and poultry under the conditions of use?

Under the Memorandum Of Understanding (MOU) for the joint USDA Food Safety
and Inspection Service (FSIS) and FDA ingredient approval process, FDA is
authorized to determine the safety of substances, as well as prescribe safe
conditions of use. FSIS is responsible for evaluating the suitability of
the use of new ingredients (when the use involves meat or poultry
products). "Suitability" relates to the effectiveness of the substance in
performing the intended technical purpose of use, at the lowest level
necessary, and the assurance that the conditions of use will not result in
an adulterated product or one that misleads consumers. In regard to L.
Monocytogenes control, the guidance has been at least a 1 log reduction
(for an antimicrobial agent used to reduce or eliminate Listeria) and no
more than 2 logs growth during a product's shelf life (for an antimicrobial
agent that is intended to suppress the growth of Listeria). Therefore, to
satisfy FSIS' concerns, the petitioner included data that showed that the
use of the phage preparation was effective in reducing/controlling Listeria
without resulting in an adulterated product or one that misleads consumers.
8. Will the additive be declared on the food label?

Use of this additive must comply with the Federal Meat Inspection Act or
the Poultry Products Inspection Act, which are both administered by USDA.
According to USDA, the use of the phage preparation will need to be
declared as an ingredient on the label of the treated meat or poultry
product, e.g., "bacteriophage preparation." In addition, when the phage is
applied to meat and poultry products with standards of identity that do not
permit the addition of antimicrobial agents, the products will need to be
descriptively named, e.g., "beef steak treated with an antimicrobial
solution to reduce microorganisms." 

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