Food Safety and Pathogens Quiz

Food Pathogens and Foodborne Diseases

• Foodborne illness, also known as food poisoning, is any illness caused by consuming contaminated food or beverages.
• These illnesses are caused by pathogenic microorganisms (bacteria, viruses, parasites, fungi, or toxins).
• A foodborne disease outbreak is defined by Federal Regulatory Agencies when two or more people experience similar illness symptoms after eating a common food.

Learning Outcomes

• Explain food poisoning and foodborne diseases
• Explain food poisoning caused by:
• Staphylococcus aureus
• Clostridium species
• Bacillus cereus
• Explain foodborne disease caused by:
• Salmonella
• Escherichia coli
• Listeria
• Vibrio
• Campylobacter

Foodborne Disease

• Foodborne illness refers to illness caused by consuming contaminated food or beverages.
• These illnesses are caused by pathogenic microorganisms that includes bacteria, viruses, parasites, fungi, and toxins.

Foodborne Disease: Food Intoxication vs. Food Infection

• Food intoxication is illness caused by consuming food or beverages containing toxins produced by pathogens.

• The illness is caused by toxins already present in the contaminated food when consumed.

• The bacteria that produced the toxin may later be killed but the toxin remains. (heat stable)

• Food infection is caused by consuming food or water contaminated with live pathogenic microorganisms.

• The illness is caused by live pathogens colonizing and multiplying in the gastrointestinal tract.

Food Intoxication: Staphylococcus Aureus

• Staphylococcal food intoxication is foodborne illness caused by consuming food contaminated with toxins produced by Staphylococcus aureus bacteria.
• Staphylococcus aureus is a round-shaped bacterium (cocci), appearing in clusters (staphylococci), like a bunch of grapes, under a microscope.
• It produces heat-stable toxins known as staphylococcal enterotoxins.
• Source of pathogen: humans (skin, nose, throat, colon, and urine).
• Vehicles: hand contact with food, without subsequent cooking or inadequate heating/refrigeration.
• Symptoms: Nausea, vomiting, abdominal cramps, diarrhea, watery and sometimes bloody, fever, headache, muscle aches. Symptoms develop after 4 hours, last for several hours, recovery occurs within 1-2 days.
• Prevention: prevent cross-contamination, proper cooking and sanitation.

Gram-positive Spore Forming Food Poisoning

• Gram-positive spore-forming rods cause bacterial food poisoning, including:
• Clostridium perfringens
• Clostridium botulinum
• Bacillus cereus

Food Intoxication: Clostridium Botulinum

• Botulism is a food intoxication caused by Clostridium botulinum.
• Anaerobic gram-positive rod-shaped bacteria produces botulinum toxin under anaerobic conditions (e.g. improperly canned or preserved foods lacking oxygen).
• Toxins (A, B, C, D, E, F, and G) cause illness in humans.
• Source: environment (soil, river, sea water).
• Vehicles: improperly canned or preserved foods.
• Symptoms: Develop 12-72 hours after ingestion. Include nausea, vomiting, fatigue, dizziness, headache, dryness of skin, mouth, and throat, constipation, paralysis of muscles, double vision. Severe cases can lead to death from respiratory muscle paralysis.

Food Intoxication: Clostridium Perfringens

• Clostridial food poisoning is caused by Clostridium perfringens.
• Produces toxins (enterotoxins) in intestines after contaminated food is consumed.
• Anaerobic gram-positive rod-shaped bacteria.
• Spore former (cannot be killed by boiling) - vehicles: gravies, meat, poultry, foods cooked in batches, foods held at unsafe temperatures.
• Symptoms: Abdominal/stomach cramps; watery diarrhea; doesn't cause nausea or fever. Symptoms develop after 6-24 hours; lasts 1-2 weeks.
• Prevention: Control temperature; store excess food properly.

Food Infection: Salmonella

• Infection caused by Salmonella bacteria.
• Rod-like, gram-negative, facultative anaerobic, non-spore-forming bacteria.
• Pathogenic Salmonella can cause typhoid fever (serious and life-threatening).
• Source: intestinal tracts of animals (human).
• Vehicles: Raw or undercooked meat, poultry, seafood, shellfish, raw fruits or vegetables, unpasteurized milk/dairy products, contaminated water.
• Symptoms: Headache, fever, watery diarrhea, abdominal pain, cramps, nausea, or vomiting.
• Prevention: Hand washing, avoid unpasteurized milk, properly cook foods.

Food Infection: Escherichia Coli

• Illness caused by a strain of E. coli bacteria (gram-negative bacteria, facultative anaerobes, rod-shaped).
• Source: intestinal tract of warm-blooded animals.
• Vehicles: Milk products, beef products, eggs, poultry, and contaminated water.
• Symptoms: Watery diarrhea (sometimes bloody), low fever, loss of appetite, nausea, vomiting, stomach pains, cramps, fatigue. Symptoms develop within 12-24 hours, persist 2-3 days.
• Prevention: Prevent cross-contamination, properly cook food, wash fruits and vegetables.

Food Infection: Listeria Monocytogenes

• Infection caused by Listeria monocytogenes (gram-positive, facultative anaerobic, nonspore-forming rods).
• Highly resistant bacteria that can survive various conditions (4°C, high salt concentrations, wide pH range).
• Source: soil, water, animal feces, decaying vegetation.
• Vehicles: ready-to-eat refrigerated foods, salads, unpasteurized dairy products, raw meats & poultry, fruits & vegetables, process foods (soft cheeses, deli meats, hotdogs, & refrigerated seafood).
• Symptoms: Muscle aches, diarrhea, severe headache, stiff neck, nausea, vomiting, meningitis (brain infection).
• Prevention: Proper cooking, avoid contact with raw foods & unpasteurized products.

Food Infection: Vibrio

• Vibriosis and cholera (caused by Vibrio bacteria).
• Gram-negative bacteria (curved or comma-shaped rods)
• Facultative anaerobes, salt-tolerant.
• Sources: aquatic environments in water, shellfish, and feces of diseased persons.
• Vehicles: Raw or undercooked shellfish, direct contact with sea water & exposure to contaminated sea water, contaminated drinking water.
• Symptoms: Watery stool, stomach pain, nausea, vomiting, fever, chills. Symptoms usually develop within 12-24 hours after exposure.
• Prevention: Cook shellfish thoroughly, avoid raw seafood contact.

Food Infection: Campylobacter

• Campylobacteriosis (caused by Campylobacter bacteria, primarily Campylobacter jejuni and Campylobacter coli).
• Gram-negative, spiral-shaped.
• Sources: Warm-blooded animals (poultry, cattle, pigs, sheep, ostriches, pets). Also found in untreated surface water (fecal matter).
• Vehicles: Undercooked meat and meat products, undercooked poultry and poultry products, raw or unpasteurized milk & dairy products. Untreated or contaminated water, raw vegetables.
• Symptoms: Headache, fatigue, fever, abdominal cramps, nausea or vomiting, bloody diarrhea.
• Prevention: Cook foods thoroughly; keep pets from food preparation areas.

General Food Safety Practices to Prevent Foodborne Illness

• Proper cooking and reheating to kill bacteria
• Separate raw and cooked foods to prevent cross-contamination.
• Keeping hot food hot and cold food cold.
• Wash hands, utensils, and surfaces thoroughly.

Test your knowledge on food safety, pathogens, and the prevention of foodborne illnesses with this quiz. Explore key practices, symptoms, and factors associated with food poisoning to enhance your understanding of food safety protocols.