Handbook of Meat Processing

Microbial Hazards in Foods: Food-Borne Infections and Intoxications 497

and decontamination of food - preparation

environment will also help reduce risks.

Much research has been devoted to the

rapid isolation, enumeration, and identifi ca-

tion of this organism. Many diagnostic kits,

immunological systems, and genetic systems

have been developed to rapidly screen for

this organism in the food supply.

Currently, there is an important debate as

to the regulation of allowed levels of L.

monocytogenes in foods. In the United States,

there is zero tolerance of L. monocytogenes

in ready - to - eat (RTE) foods and even in the

environment and processing equipment for

manufacturing RTE. This is a very stringent

rule. However, Canada and the European

Union allow 100 L.m./g of certain foods to be

further processed in certain conditions.

Currently, there is a move to suggest the

United States should follow the 100 L.m./g

allowance, as it is almost impossible to

enforce the zero - tolerance rule in current

U.S. regulation. The debate goes on. In 2002,

3 outbreaks involving 100 cases and 2 deaths

were reported.

Aeromonas hydrophila

Aeromonas hydrophla has been associated

with food - borne infection, although the

evidence is inconclusive. The organism

is a facultative anaerobic, Gram - negative,

motile rod. Biochemically, it is similar to

E. coli and Klebsiella. The optimal tempera-

ture for growth is 28 ° C and the maximum

is 42 ° C. Many strains can grow at 5 ° C,

which is a temperature usually considered

adequate to prevent growth of food - borne

pathogens.

Diseases caused by A. hydrophila include

gastroenteritis (cholera - like illness and dys-

entery - like illness) and extra - intestinal infec-

tions such as septicemia and meningitis. This

organism has been isolated from fi sh, shrimp,

crabs, scallops, oysters, red meats, poultry,

raw milk, vacuum - packaged pork and beef,

and even bottled mineral water.

Massachusetts (1983), and the most well -
known one involving Mexican - style soft
cheese in southern California (1985). Due to
concerted effort by the food industry and
government agencies, the outbreaks of L.
monocytogenes seemed to have subsided for
about 10 years. Between 1988 and 1992, only
one outbreak involving two cases and one
death was recorded for L. monocytogenes,
and it appeared that the problem of L. mono-
cytogenes was under control. However, in
1998 and 1999 the organism was found on
surfaces and equipment of frankfurter pro-
duction lines, air condition lines, hot dogs,
lunch meat, and turkey breasts, causing many
outbreaks and recalls. One company recalled
30 million pounds of ready - to - eat products
due to L. monocytogenes. Another company
recalled 15 million pounds of hot dogs and
deli meat products due to an outbreak of L.
monocytogenes that included 20 deaths — 14
adults and 6 miscarriages/stillbirths — and at
least 97 illnesses in 22 states. In 2002, there
were 3 outbreaks with 100 cases and 2 deaths
recorded. There is a resurgence of concern
about this organism due to the pathogenic
nature of the illness resulting in miscarriages
and stillbirths.
L. monocytogenes has been isolated in a
variety of commodities, including poultry
carcasses, meat and chopped beef, dry sau-
sages, milk and milk products, cheese, veg-
etables, and surface water. Control measures
include eliminating the occurrence of the
organism in raw - food materials, transporting
vehicles, and food - processing plants (where
it is especially important to control cross con-
tamination of raw and fi nished products);
practicing good general sanitation of the
entire food - processing environment; regular
monitoring for this organism in food -
processing facilities; and preventing preg-
nant females from working in and around
environments that have the possibility of
exposure to L. monocytogenes. Because the
organism is killed by heat and is susceptible
to sanitizing agents, proper cooking of food