disease-causing microorganisms and the conditions they need to grow barriers for controlling the...
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Disease-Causing Microorganisms and the Conditions They Need to Grow
Barriers for Controlling the Growth of Microorganisms
Microorganism Small living organism
Pathogen A disease-causing microorganism
Toxin Poison
Spoilage Microorganism Microorganism that causesspoilage, but not illness
Bacteria Viruses Parasites Fungi
Microorganisms That Can ContaminateFood and Cause Foodborne Illness
Living, single-celled Carried by food, water, humans and insects Can reproduce rapidly Some survive freezing Some form spores Some spoil food; others cause disease Some cause illness by producing toxins
Acidity Pathogenic bacteria grow well at a pH of 4.6 to 7.5
Raw Chicken 5.5–6.4
Egg Yolks 6.0–6.3
Butter 6.0–6.8
Temperature The Temperature Danger Zone(TDZ) = 41ºF to 140ºF (5ºC to 60ºC)
Most microorganisms grow well in the TDZ
Some survive and grow outside the TDZ
Time Pathogenic microorganisms can grow to high levels if they remain in the TDZ for more than four hours
Oxygen Microorganisms have differentoxygen needs for growth
Aerobic needs oxygen to grow
Anaerobic grows only when oxygen is absent
Facultative can grow with or without oxygen
Moisture Most potentially hazardous foods have a water activity of .85 or above
Raw Chicken and Butter Water Activities of .95–1.0
Barriers That Control the Growthof Microorganisms
Make the foodmore acidic
Raise or lowerthe temperature of the food
Lower the water activity
Lessen the time in the TDZ
Salmonellosis Shigellosis Listeriosis Staphyloccocal food poisoning Clostridium perfringens Enteritis
Major Foodborne Illnesses Caused by Bacteria
Bacillus cereus gastroenteritis Botulism Campylobacteriosis E. coli O157:H7 EHEC Vibrio gastroenteritis Yersiniosis
Can’t reproduce outside a living cell Do not require a PHF to be transmitted Usually contaminate food through poor personal hygiene May survive freezing and cooking Contaminate food and water
Hepatitis A Norwalk Virus Gastroenteritis Rotavirus Gastroenteritis
Major Foodborne Illnesses Caused by Viruses
Freeze properly Cook to proper temperatures Avoid cross-contamination Use sanitary water supplies Wash hands properly
Keys to Prevention
Trichinosis Anisakiasis Giardiasis Toxoplasmosis Intestinal Cryptosporidiosis Cyclosporiasis
Major Foodborne Illnesses Caused by Parasites
Foodborne Infections Result when pathogens grow in intestines after a person eats food contaminated by them
Foodborne Intoxications Result from eating food containing poisonous toxins
Foodborne Toxin-Mediated Infections Result from toxins produced by pathogens growing in the intestines
Prepare an outline for a discussion of the four types of microorganisms. Include examples of what microorganisms need to survive and grow. Highlight the conditions managers have the most influence over.
Challenge participants to create a list of foods high in acid and another list of highly alkaline foods. Reward the participant who comes up with the most examples and have him or her share the list with the class.
Create a blank handout of a thermometer and have participants indicate the space for the temperature danger zone.