Download E. coli

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 causes
spoilage, but not illness
Microorganisms That Can Contaminate
Food and Cause Foodborne Illness
Bacteria
Viruses
Parasites
Fungi

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
Growth Stages of Bacteria
Bacterial Growth
What Microorganisms Need to Grow
Food
Microorganisms require
nutrients to grow

Proteins

Carbohydrates
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 different
oxygen 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 Growth
of Microorganisms
Make the food
more acidic
Raise or lower
the temperature
of the food
Lower the
water activity
Lessen the
time in the TDZ
Major Foodborne Illnesses
Caused by Bacteria

Bacillus cereus
gastroenteritis
Listeriosis

Botulism
Staphyloccocal
food poisoning

Campylobacteriosis

E. coli O157:H7 EHEC

Vibrio gastroenteritis

Yersiniosis

Salmonellosis

Shigellosis



Clostridium perfringens
Enteritis
Salmonellosis
Type of Illness: Infection, possibly toxin-mediated
Listeriosis
Type of Illness: Infection
Staphylococcal Food Poisoning
Type of Illness: Intoxication
Clostridium perfringens
Type of Illness: Toxin-mediated infection
Botulism
Type of Illness: Intoxication
E. coli O157:H7 EHEC
Type of Illness: Toxin-mediated infection

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
Major Foodborne Illnesses
Caused by Viruses

Hepatitis A

Norwalk Virus Gastroenteritis

Rotavirus Gastroenteritis
Hepatitis A
Type of Illness: Infection
Norwalk Virus Gastroenteritis
Type of Illness: Infection
Parasites
Need to live in or on a host
organism in order to survive
Host
Person
Animal
Plant
Keys to Prevention

Freeze properly

Cook to proper temperatures

Avoid cross-contamination

Use sanitary water supplies

Wash hands properly
Major Foodborne Illnesses
Caused by Parasites

Trichinosis

Anisakiasis

Giardiasis

Toxoplasmosis

Intestinal Cryptosporidiosis

Cyclosporiasis
Trichinosis
Type of Illness: Infection
Anisakiasis
Type of Illness: Infection
Fungi
Commonly cause food
spoilage, not illness
Fungi
Molds
Yeasts
Mushrooms
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.