Food Toxicology 2(2+0)






Bacillus cereus
There are frequent associations of B. cereus emetic effects with rice dishes, although the reason for the association is not known. Usually, the organism causes a self-limiting type of food poisoning. Occasionally, the organism can be fatal in immune compromised individuals.

Bacillus anthracis is found in the soil, causing many animals to die of anthrax. The organism can be found in the gastrointestinal (GI) tract of an animal that survives the disease.

Anthrax cannot be passed through the air, so the infectious rate is low; however, the exception is cutaneous anthrax, wherein contact with drainage from an open sore can spread the bacteria. Fatalities are high (>80%), particularly by the inhalation route, unless treated with antibiotics. Another possible route of infection is through eating contaminated food, causing gastrointestinal anthrax. Eating meat from infected animals is the usual means of exposure. Anthrax became infamous in the aftermath of September 11, 2001, as a suspected tool for bioterrorism.

Inhalation anthrax results in malaise, fatigue, and sometimes a dry cough. Often the subject experiences improvement, but that is followed by a decline, with breathing trouble, sweating, and bluish discoloration of the skin. The subject experiences shock and death 24 to 36 h after the severe symptoms begin. For cutaneous skin anthrax, individuals experience low fever, skin lesions, and swelling.. Two distinct types of illnesses are associated with food poisoning from B. cereus . Within 4 to 16 h of incubation, there is the diarrheal illness, manifested as abdominal pain and diarrhea. Such symptoms usually subside within 12 to 24 h. There also is an emetic illness of shorter incubation, 1to 5 h, producing nausea and vomiting.

Clostridium botulinum

Widely distributed in nature; soil, water, on plants, and intestinal tracts of animals and fish. Grows only in little or no oxygen.

Bacteria produce a toxin that causes illness. Improperly canned foods, garlic in oil, vacuum-packed and tightly wrapped food.

Toxin affects the nervous system. Symptoms usually appear 18 to 36 hours, but can sometimes appear as few as 4 hours or as many as 8 days after eating; double vision, droopy eyelids, trouble speaking and swallowing, and difficulty breathing. Fatal in 3 to 10 days if not treated.

Staphylococcus aureus

On humans (skin, infected cuts, pimples, noses, and throats).

Person-to-person through food from improper food handling. Multiply rapidly at room temperature to produce a toxin that causes illness.

Severe nausea, abdominal cramps, vomiting, and diarrhea occur 1 to 6 hours after eating; recovery within 2 to 3 days – longer if severe dehydration occurs.

Last modified: Monday, 26 March 2012, 1:56 PM