Common Food Plant Pathogens

Proper name

Bacillus cereus

Description:

A gram positive aerobic sporeformer.

Typical source of contamination:

Soil and starchy foods such as rice

Products of concern:

Unrefrigerated cooked foods

Symptoms:

A wide variety of foods including meats, milk, vegetables, and fish have been associated with the diarrheal type food poisoning. The vomiting-type outbreaks have generally been associated with rice products; however, other starchy foods such as potato, pasta and cheese products have also been implicated. Food mixtures such as sauces, puddings, soups, casseroles, pastries, and salads have frequently been incriminated in food poisoning outbreaks.

Complications possible:

Severe systemic and pyogenic infections, gangrene, septic meningitis, cellulitis, panophthalmitis, lung abscesses, infant death, and endocarditis.

Susceptible populations:

All

Proper name

Campylobacter jujuni

Description:

A gram negative bacteria requiring low oxygen levels. This bacteria is the leading cause of bacterial diarrheal illness.

Typical source of contamination:

Cattle, birds including chickens, flies and environmentally in non chlorinated water sources.

Products of concern:

Raw chicken, unpasteurized milk.

Symptoms:

Diarrhea

Complications possible:

Haemolytic uremic syndrome, internal organ infections

Susceptible populations:

All although children under 5 and young adults between 15 and 29 appear particularly susceptible.

Proper name

Clostridia botulinum

Description:

A gram positive anaerobic spore former that produces a neurotoxin. There are 4 strains that cause botulism in humans.

Typical source of contamination:

Soil, intestinal tracts of fish and animals, shellfish

Products of concern:

Improperly canned foods primarily

Symptoms:

Lack of energy, weakness, dizziness, double vision, difficulty speaking, swallowing and breathing.

Complications possible:

Paralysis, death.

Susceptible populations:

All

Proper name

Clostridium perfringens

Description:

A gram positive anaerobic spore former

Typical source of contamination:

Widely distributed in the environment and may be present in the intestines of humans and animals.

Products of concern:

Meat and meat products

Symptoms:

Abdominal cramps and diarrhea.

Complications possible:

Death due to dehydration. Rarely necrotic enteritis.

Susceptible populations:

Children and the elderly.

Proper name

Escherichia coli (E coli)

Description:

There are 4 classes of E coli that cause diarrhea in humans. The strain most often of concern in food processing is O157:H7

Typical source of contamination:

Feces of animals or humans.

Products of concern:

Ground meats, dry cured meats and sausages, cheese curds, vegetables, unpasteurized juices.

Symptoms:

Severe cramping and diarrhea. Occasionally vomiting.

Complications possible:

Hemolytic uremic syndrome.

Susceptible populations:

Young children and the elderly particularly for potentially fatal complications.

Proper name

Listeria monocytogenes

Description:

Gram positive bacteria widely distributed in the environment which can be present in the intestines of humans and animals. Very hardy and can survive freezing and drying. Can multiply at refrigeration temperatures.

Typical source of contamination:

Environmental

Products of concern:

Ready to eat foods, raw and cooked meats, soft cheeses, raw vegetables.

Symptoms:

For most healthy people there are no symptoms and the bacteria causes no ill effects. For the susceptible populations listeriosis can cause nausea, septicaemia, meningitis, uterine or cervical infections in pregnant women, vomiting, diarrhea.

Complications possible:

Still birth, death. Mortality rates as high as 70% have been quoted.

Susceptible populations:

Pregnant women, elderly, immunocompromised individuals.

Proper name

Salmonella

Description:

Widespread gram negative bacteria

Typical source of contamination:

All animals but particularly pigs and poultry, water, soil, insects, animal feces, raw foods

Products of concern:

Raw meats, eggs, diary products, seafood, sauces & salad dressings, powdered products, peanut butter, chocolate

Symptoms:

Nausea, vomiting, diarrhea, fever and headache. Chronic consequences are arthritic symptoms.

Complications possible:

Typhoid and typhoid like fevers, arthritis, death.

Susceptible populations:

All but particularly infants, elderly and AIDS patients.

Proper name

Shigella

Description:

A gram negative bacteria

Typical source of contamination:

Human feces

Products of concern:

Salads, raw vegetables, milk and diary products, poultry.

Symptoms:

Abdominal cramping and pain, diarrhea, fever, vomiting.

Complications possible:

Hemolytic uremic syndrome, arthritis, death.

Susceptible populations:

All but particularly infants and elderly.

Proper name

Staphylococcus aureus

Description:

A gram positive bacteria

Typical source of contamination:

Staphylococci exist in air, dust, sewage, water, milk, and food or on food equipment, environmental surfaces, humans, and animals. Humans and animals are the primary reservoirs

Products of concern:

Meat and meat products; poultry and egg products; salads such as egg, tuna, chicken, potato, and macaroni; bakery products such as cream-filled pastries, cream pies, and chocolate eclairs; sandwich fillings; and milk and dairy products. Foods that require considerable handling during preparation and that are kept at slightly elevated temperatures after preparation are frequently involved in staphylococcal food poisoning.

Symptoms:

Nausea, vomiting and cramping. In severe cases headache and muscle cramping may occur.

Complications possible:

Rarely, death of the elderly or infants.

Susceptible populations:

All