Food borne Biohazards

Biotoxins

• Biotoxin is a poisonous substance that is a specific product of the metabolic activities of a living organism (Plant, animal, bacteria, fungus).

• Cause food intoxications

• Toxicity depends on dose

Food Intoxication

• Microbes grow in foods produce toxins.

• Toxins are ingested with the food and cause health problems.

• Most heat treatments are effective to kill microbes, but toxins remain

Toxin classification

Organism Toxin

Bacteria Botulinum toxin, Staphylococcus toxin

Fungi Afalatoxin, Mycotoxin, Ochratoxin, Patulin

Toxic algae Okadaic acid

Natural toxins Histamine, Glycoalcoloids

Toxin characteristics

• Non replicative (Most are proteinaceous)

• Non transmittable (human to human)

• Nonvolatile

• Colorless

• Odorless

• Tasteless

• Most are stable at standard conditions

Botulism toxin

• Agent: Chlostridium botulinum

• Toxicity: 1ng/kg

– 500g is enough to kill the human race

• Disturb the acetylecholine mechanism at neuromuscular junctions

• Symptoms

– Nausea, vomiting, diarrhea, headache, lethargy, double vision, respiratory stress, death

Food sources

• Improperly canned foods (>pH 4.6)

• Smoked salmon, trout

• Fermented foods (Saeurkraut, pickled vegetables)

• Foods preserved in oil (Fish)

Staphylococcus toxin

• Agent: Staphylococcus aureus

• Toxicity: 1μg cause illness

• Disturbs the regulation of intestinal fluid regulation system

• Symptoms:

– Sudden nausea, vomiting, excessive salivation, abdominal cramps, diarrhea, dehydration

• Toxin is heat stable

Food sources

• Cooked ham, meat products, poultry

• Home made sausages

• Milk, cheese

• Cream filled pastries

Afalatoxin

• Agent: Aspergillus flarus

• Afalatoxin B1, B2, G1, G2 (B1 is the most common)

• Toxicity: 0.5-10 mg/kg

• Liver cancer, chronic hepatitis, jaundice, cirrhosis (Low levels long time)

• Cause acute toxicity, and potentially death (High exposure)

Food Sources

• Peanuts and peanut butter

• Tree nuts such as pecans

• Corn

• Wheat

• Oil seeds such as cottonseed

Ochratoxin

• Agent: Aspergillus ochraceus

• Toxicity: No documented acute toxicity in humans

• Tolerable weekly intake 120ng/kg (EFSA)

• Has genotoxic and teratogenic effects

• Relatively heat stable

Food Sources

• Soy beans

• Coffee beans

• Grapes

• Peanuts

• Cereals

Patulin

• Agent: Aspergillus clavatus. Penicilliumexpansum

• Toxicity: No documented acute toxicity

• Provisional maximum tolerable daily intake 0.4μg/kg

• Relatively heat stable and not destroyed by pasteurization

Food Sources

• Apple and apple juice

• Pears, grapes, bilberries may affect

• Sweet cider

How to control

• Good agricultural practices to avoid insect damages and mold infection

• Good storage practices (Store below 100C, control moisture, control RH)

• Separation of contaminated foods before processing

How to control

• Follow proper food handling and canning methods

• Maintain good hygienic practices

• Rules and Regulations

Referenes

• http://www.foodsafetywatch.org/category/factsheets/biotoxins/