Fundamental Food Microbiology, Third Edition - Fuad Fathir

FOODBORNE TOXICOINFECTIONS 403
subgroups. Direct or indirect contamination of these foods (and water) with fecal
materials, along with improper storage temperature and inadequate heat treatment,
were involved in these incidences.
G. Prevention
The most important factor in the prevention of gastroenteritis in humans by pathogenic
Esc. coli is to prevent contamination of food and water, directly or indirectly,
by fecal matters. This can be achieved by developing effective sanitation in water
supplies and treating and disposing sewage. The other factor is the prevent contamination
of food due to poor personal hygiene by people who shed the pathogen.
Finally, one needs to recognize that even if the pathogen is present in very small
initial numbers in a food, temperature abuse of the food can facilitate multiplication
of cells to high levels necessary for the disease symptoms. Thus, food should be
refrigerated or eaten quickly, preferably after reheating. 3,12
H. Detection Methods
The detection methods used involved selective enrichment of sample (food, water,
and feces), isolation of pathogens on selective agar medium, and biochemical characterization
of suspected isolates. Confirmation tests to detect toxins involve one or
more serological tests (ELISA). Other methods to detect toxins include injecting
test material into the ligated ileal loop of infant mice or exposing Y-1 adrenal cells
to toxin (for LT), or both.
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VI. CONCLUSION
Foodborne pathogens in this group include several Gram-positive sporeformers and
Gram-negative rods. The cells of sporeformers, when consumed through contaminated
foods, sporulate in the gastrointestinal (GI) tract and release the toxin. In
contrast, following consumption, Gram-negative rods multiply rapidly in the GI tract
and die off, releasing toxins. The symptoms, mainly enteric, are associated with the
toxins. They are usually required in very high numbers to cause the diseases. Proper
sanitation and refrigeration can be used to reduce the incidence.
REFERENCES
1. Bean, N.H. and Griffin, P.M., Foodborne disease outbreaks in the United States, 1973-
1987, J. Food Prot., 53, 804, 1990.
2. Bean, N.H., Griffin, P.M., Goulding, J.S., and Ivey, C.B., Foodborne disease outbreaks,
5 year summary, 1983-1987, J. Food Prot., 53, 711, 1990.
3. Garvani, R.B., Food science facts, Dairy Food Environ. Sanit., 7, 20, 1987.
4. Labbe, R.G., Clostridium perfringens, Food Technol., 42(4), 195, 1988.