The Microworld

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The Microworld
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Apply Your Knowledge Test Your Food Safety
Knowledge

• True or False Bacillus cereus is commonly
  associated with cereal crops, such as rice
• 2. True or False A foodborne intoxication
  results when a person eats food containing
  pathogens, which then grow in the intestines and
  cause illness
• 3. True or False Cooking food to the required
  minimum internal temperature can help avoid
  listeriosis
• 4. True or False A person with shigellosis may
  experience bloody diarrhea
• 5. True or False Highly acidic food typically
  does not support the growth of foodborne
  microorganisms

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Microbial Contaminants

• Microorganism
• Small, living organism
• Pathogen
• Illness-causing microorganism
• Toxin
• Poison

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Microbial Contaminants

• Microorganisms That Can Contaminate Food and
  Cause Foodborne Illness

Bacteria
Viruses
Parasites
Fungi
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What Microorganisms Need to Grow FAT TOM
A
T
F
Food
Temperature
Acidity
T
M
O
Moisture
Time
Oxygen
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What Microorganisms Need to Grow FAT TOM

• Food
• Foodborne microorganisms require nutrients to
  grow. Specifically carbohydrates and proteins
• These are found in potentially hazardous food
  including
• Meat
• Poultry
• Dairy products
• Eggs

F
Food
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What Microorganisms Need to Grow FAT TOM

• Acidity
• Foodborne microorganisms grow best in food that
  has a neutral or slightly acidic pH (7.5 to 4.6)
• Most food falls into this range

A
Acidity
pH Scale
Acidic
7.54.6 ideal for bacterial growth
Neutral
Alkaline
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What Microorganisms Need to Grow FAT TOM

• Temperature
• Foodborne microorganisms grow well at
  temperatures between 41F and 135F (5C and
  57C)

T
Temperature
135F (57C)
The Temperature Danger Zone
41F (5C)
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What Microorganisms Need to Grow FAT TOM

• Time
• Foodborne microorganisms need sufficient time to
  grow
• 4 hours or more in TDZgrowth high enough to
  cause illness

T
Time
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What Microorganisms Need to Grow FAT TOM

• Oxygen
• Some foodborne microorganisms require oxygen to
  grow, while others grow when oxygen is absent

O
Oxygen
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What Microorganisms Need to Grow FAT TOM

• Moisture
• Most foodborne microorganisms require
  moisture to grow
• The amount of moisture available in food for
  this growth is called water activity (aw)
• Potentially hazardous food typically has an aw
  of .85 or higher

M
Moisture
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Controlling the Growth of Microorganisms

• The two conditions you can control
• Temperature
• Refrigerate or freeze food properly
• Cook food properly
• Time
• Minimize time food spends in the temperature
  danger zone (TDZ)

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Apply Your Knowledge What I Need to Grow!

• Which conditions typically support the growth of
  microorganisms?
• Food that is high in fat
• Food that contains protein
• pH of 9.0
• Temperature of 155?F (68?C) or higher
• Dry environment

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Classifying Foodborne Illness

• Foodborne Infections
• Result when a person eats food containing
  pathogens, which then grow in the intestines and
  cause illness
• Foodborne Intoxications
• Result when a person eats food containing toxins
  that cause illness
• Foodborne Toxin-Mediated Infections
• Result when a person eats food containing
  pathogens, which then produce illness-causing
  toxins in the intestines

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Bacteria That Cause Foodborne Illness

• Basic Characteristics
• Living, single-celled organism
• Can be carried by food, water, soil, animals,
  humans, or insects
• Can reproduce very rapidly under favorable
  conditions

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Bacteria That Cause Foodborne Illness

• Basic Characteristics continued
• Some survive freezing
• Some change into a different form called spores
  to protect themselves
• Some spoil food others cause illness
• Some produce toxins that cause illness

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Spores

• Certain bacteria can change into a different
  form, called spores, to protect themselves
• Spores
• Form when nutrients are not available
• Are commonly found in soil and contaminate food
  grown there
• Can contaminate meat, poultry, fish, and other
  food exposed to soil or dust

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Spores

• Spores
• Can resist heat, allowing them to survive cooking
  temperatures
• Can revert back to a form capable of growth when
• Food is not stored at the proper temperature
• Food is not held or cooled properly

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Major Foodborne Illnesses Caused by Bacteria

• Infections
• Campylobacteriosis
• Salmonellosis
• Shigellosis
• Listeriosis
• Vibrio parahaemolyticus Gastroenteritis
• Vibrio vulnificus Primary Septicemia/Gastroenterit
  is

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Infection Campylobacteriosis

Illness Campylobacteriosis
Bacteria Campylobacter jejuni
Most Common Symptoms
Commonly Associated Food
Most Common Symptoms

• Diarrhea (may be bloody)
• Abdominal cramps
• Fever
• Headache

• Poultry
• Water contaminated with the bacteria

Diarrhea Abdominal Cramps Fever
Headache
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Preventing Campylobacteriosis

• To reduce the bacteria in food
• Cook food, particularly poultry, to required
  minimum internal temperatures
• To prevent the transfer of the bacteria
• Prevent cross-contamination between raw poultry
  and ready-to-eat food.

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Infection Salmonellosis

Illness Salmonellosis Bacteria Salmonell
a spp.
Commonly Associated Food
Most Common Symptoms

• Diarrhea
• Abdominal cramps
• Vomiting
• Fever

• Poultry and eggs
• Dairy products
• Beef

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Preventing Salmonellosis

• To reduce the bacteria in food
• Cook raw beef, poultry, and eggs to required
  minimum internal temperatures.
• To prevent the transfer of the bacteria
• Minimize cross-contamination between raw meat and
  poultry and ready-to-eat food.
• Exclude foodhandlers diagnosed with
  salmonellosis.

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Infection Shigellosis
Illness Shigellosis Bacteria Shigella
spp.
Most Common Symptoms
Commonly Associated Food
Most Common Symptoms

• Food easily contaminated by hands
• Food in contact with contaminated water (i.e.,
  produce)

• Bloody diarrhea
• Abdominal pain and cramps
• Fever (occasionally)

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Preventing Shigellosis

• To prevent the transfer of the bacteria
• Exclude foodhandlers if they
• Have diarrhea
• Have been diagnosed with shigellosis
• Wash hands when necessary
• Control flies inside and outside the establishment

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Infection Listeriosis

Illness Listeriosis Bacteria Listeria
monocytogenes
Most Common Symptoms
Commonly Associated Food
Most Common Symptoms

• Raw meat
• Unpasteurized milk and milk products
• Ready-to-eat food including
• Deli meats
• Hot dogs
• Soft cheese

• Pregnant women
• Spontaneous abortion of the fetus
• Newborns
• Sepsis
• Pneumonia
• Meningitis

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Preventing Listeriosis

• It is critical to
• Discard product that has passed its use-by or
  expiration date
• Avoid using unpasteurized dairy products
• To reduce the bacteria in food
• Cook raw meat to required minimum internal
  temperatures
• To prevent the transfer of the bacteria
• Prevent cross-contamination between raw or
  undercooked and ready-to-eat food

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Infection Vibrio parahaemolyticus Gastroenteritis
Illness Vibrio parahaemolyticus
Gastroenteritis Bacteria Vibrio
parahaemolyticus
Commonly Associated Food
Most Common Symptoms

• Raw or partially cooked oysters

• Diarrhea and abdominal cramps
• Nausea and vomiting
• Low grade fever and chills

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Preventing Vibrio parahaemolyticus Gastroenteritis

• Most Important Prevention Measures
• Purchase oysters from approved, reputable
  suppliers
• Cook oysters to the required minimum internal
  temperature

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Infection Vibrio vulnificus Primary Septicemia
Illness Vibrio vulnificus Primary
Septicemia Bacteria Vibro vulnificus
Commonly Associated Food
Most Common Symptoms

• Raw or partially cooked oysters

(People with liver disease and diabetes)

• Fever and chills
• Nausea
• Skin lesions
• Diarrhea and vomiting possible

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Infection Vibrio vulnificus Gastroenteritis
Illness Vibrio vulnificus Gastroenteritis
Bacteria Vibrio vulnificus
Commonly Associated Food
Most Common Symptoms

• Raw or partially cooked oysters

• (Otherwise healthy people)
• Diarrhea
• Abdominal cramps

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Preventing Vibrio vulnificus Septicemia/Gastroente
ritis

• Most Important Prevention Measures
• Purchase oysters from approved, reputable
  suppliers.
• Cook oysters to the required minimum internal
  temperature.
• Inform people at risk to consult a physician
  before regularly consuming raw or partially
  cooked oysters

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Major Foodborne Illnesses Caused by Bacteria

• Intoxications
• Bacillus cereus Gastroenteritis
• Staphylococcal Gastroenteritis
• Botulism

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Intoxication Bacillus cereus Gastroenteritis
Illness Bacillus cereus Gastroenteritis
Bacteria Bacillus cereus (Diarrheal
Toxin)
Most Common Symptoms
Most Common Symptoms
Commonly Associated Food

• Watery diarrhea
• Abdominal cramps and pain
• Vomiting is absent

• Cooked corn
• Cooked potatoes
• Cooked vegetables
• Meat products

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Intoxication Bacillus cereus Gastroenteritis
Illness Bacillus cereus Gastroenteritis
Bacteria Bacillus cereus (Emetic
Toxin)
Most Common Symptoms
Commonly Associated Food

• Nausea
• Vomiting

• Cooked rice dishes including
• Fried rice
• Rice pudding

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Preventing Bacillus cereus Gastroenteritis

• To reduce the bacteria in food
• Cook food to required minimum internal
  temperatures
• To prevent the growth of the bacteria
• Hold food at the proper temperature
• Cool food properly

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Intoxication Staphylococcal Gastroenteritis
Illness Staphylococcal Gastroenteritis
Bacteria Staphylococcus aureus
Most Common Symptoms
Commonly Associated Food
Most Common Symptoms
Commonly Associated Food

• Nausea
• Vomiting and retching
• Abdominal cramps

• Salads containing potentially hazardous food
• Egg, tuna, chicken, macaroni
• Deli meats

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Preventing Staphylococcal Gastroenteritis

• To prevent the transfer of the bacteria to food
• Wash hands after touching the body
• Cover cuts on hands and arms
• Restrict foodhandlers with infected cuts on hands
  and arms
• To prevent the growth of the bacteria in food
• Minimize the time food spends in the TDZ
• Cook, hold, and cool food properly

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Intoxication Botulism
Illness Botulism Bacteria Clostridium
botulinum
Commonly Associated Food
Most Common Symptoms

• Improperly canned food
• ROP food
• Temperature abused vegetables like
• Baked potatoes
• Untreated garlic-and-oil mixtures

• Initially
• Nausea and Vomiting
• Later
• Weakness
• Double vision
• Difficulty speaking and swallowing

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Preventing Botulism

• Most Important Prevention Measures
• Hold, cool, and reheat food properly
• Inspect canned food for damage

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Major Foodborne Illnesses Caused by Bacteria

• Toxin-Mediated Infections
• Clostridium perfringens Gastroenteritis
• Hemorrhagic Colitis

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Toxin-Mediated Infection Clostridium perfringens
Gastroenteritis
Illness Clostridium perfringens
Gastroenteritis Bacteria Clostridium
perfringens
Commonly Associated Food
Most Common Symptoms

• Meat
• Poultry
• Meat and poultry dishes
• Stews
• Gravies

• Diarrhea
• Severe abdominal pain
• Fever and vomiting are absent

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Preventing Clostridium perfringens
Gastroenteritis

• To prevent growth of the bacteria (especially in
  meat dishes)
• Cool and reheat food properly
• Hold food at the proper temperature

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Toxin-Mediated Infection Hemorrhagic Colitis
Illness Hemorrhagic Colitis Bacteria
Shiga toxin-producing Escherichia coli

Most Common Symptoms
Commonly Associated Food
Most Common Symptoms

• Ground beef (raw and undercooked)
• Contaminated produce

• Diarrhea (eventually becomes bloody)
• Abdominal cramps
• Severe cases can result in hemolytic uremic
  syndrome (HUS)

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Preventing Hemorrhagic Colitis

• To reduce the bacteria in food
• Cook food, particularly ground beef, to required
  minimum internal temperatures
• To prevent the transfer of the bacteria to food
• Prevent cross-contamination between raw meat and
  ready-to-eat food
• Exclude employees from the establishment if
• They have diarrhea
• They have been diagnosed with hemorrhagic colitis

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Basic Characteristics of Viruses

• Viruses
• Some may survive freezing
• Can be transmitted from
• Person to person
• People to food
• People to food-contact surfaces
• Usually contaminate food through a foodhandlers
  improper hygiene
• Can contaminate both food and water supplies

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Major Foodborne Illnesses Caused by Viruses

• Viral Foodborne Illnesses
• Hepatitis A
• Norovirus Gastroenteritis

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Infection Hepatitis A

Illness Hepatitis A Virus Hepatitis A
Most Common Symptoms
Commonly Associated Food
Most Common Symptoms

• Ready-to-eat food including
• Deli meats
• Produce
• Salads
• Raw and partially cooked shellfish

• Initially
• Fever (mild)
• General weakness
• Nausea
• Abdominal pain
• Later
• Jaundice

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Preventing Hepatitis A

• To prevent the transfer of the virus to food
• Wash hands properly
• Exclude employees who have jaundice or hepatitis
  A
• Minimize bare-hand contact with ready-to-eat food
  
• Other prevention measures
• Purchase shellfish from approved, reputable
  suppliers
• Inform high-risk populations to consult a
  physician before regularly consuming raw or
  partially cooked shellfish

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Infection Norovirus Gastroenteritis
Illness Norovirus Gastroenteritis
Virus Norovirus
Most Common Symptoms
Commonly Associated Food
Most Common Symptoms

• Ready-to-eat food
• Shellfish contaminated by sewage

• Vomiting
• Diarrhea
• Nausea
• Abdominal cramps

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Preventing Norovirus Gastroenteritis

• To prevent the transfer of the virus to food
• Exclude foodhandlers with diarrhea and vomiting
• Exclude employees who have been diagnosed with
  Norovirus Gastroenteritis
• Wash hands properly
• Other prevention measures
• Purchase shellfish from approved, reputable
  suppliers

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Basic Characteristics of Parasites

• Parasites
• Are living organisms that need a host to survive
  
• Are small, often microscopic
• Infect many animals and can be transmitted to
  humans
• Are a hazard to food and water

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Major Foodborne Illnesses Caused by Parasites

• Parasitic Foodborne Illnesses
• Anisakiasis
• Cyclosporiasis
• Cryptosporidiosis
• Giardiasis

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Infection Anisakiasis
Illness Anisakiasis
Parasite Anisakis simplex
Most Common Symptoms
Commonly Associated Food
Most Common Symptoms

• Raw and undercooked
• Herring
• Cod
• Halibut
• Mackerel
• Pacific salmon

• Non-invasive
• Tingling in throat
• Coughing up worms
• Invasive
• Stomach pain
• Nausea
• Vomiting
• Diarrhea

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Preventing Anisakiasis

• Most Important Prevention Measures
• Cook fish to required minimum internal
  temperatures
• Purchase fish from approved, reputable suppliers
• If fish will be served raw or undercooked
• Purchase sushi-grade fish
• Ensure sushi-grade fish has been frozen properly
  by the supplier

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Infection Cyclosporiasis

Illness Cyclosporiasis
Parasite Cyclospora cayetanensis
Commonly Associated Food
Most Common Symptoms

• Nausea (mild to severe)
• Abdominal cramping
• Mild fever
• Diarrhea alternating with constipation

• Produce irrigated or washed with water containing
  the parasite

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Preventing Cyclosporiasis

• It is critical to
• Purchase produce from approved, reputable
  suppliers
• To prevent the transfer of the parasite to food
• Exclude foodhandlers with diarrhea
• Wash hands properly to minimize the risk of
  cross-contamination

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Infection Cryptosporidiosis
Illness Cryptosporidiosis
Parasite Cryptosporidium parvum
Commonly Associated Food
Most Common Symptoms

• Untreated or improperly treated water
• Contaminated produce

• Watery diarrhea
• Stomach cramps
• Nausea
• Weight loss

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Preventing Cryptosporidiosis

• It is critical to
• Purchase produce from approved, reputable
  suppliers
• Use properly treated water
• To prevent the transfer of the parasite to food
• Exclude foodhandlers with diarrhea
• Wash hands properly to minimize the risk of
  cross-contamination

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Infection Giardiasis

Illness Giardiasis Parasite Giardia
duodenalis
Commonly Associated Food
Most Common Symptoms

• Initially
• Fever
• Later
• Loose stools
• Abdominal cramps
• Nausea

• Improperly treated water

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Preventing Giardiasis

• Most Important Prevention Measure
• Use properly treated water
• To prevent the transfer of the parasite to food
• Exclude foodhandlers with diarrhea
• Wash hands properly to minimize the risk of
  cross-contamination

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Fungi

• Fungi
• Commonly cause food spoilage and sometimes
  illness

Fungi
Molds Yeasts
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Basic Characteristics of Mold

• Mold
• Spoils food and sometimes causes illness
• Grows well in acidic food with low water activity
• Is not destroyed by freezing
• Can produce toxins such as aflatoxins

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Basic Characteristics of Yeast

• Yeast
• Can spoil food rapidly
• May produce a smell or taste of alcohol as it
  spoils food
• May appear as a pink discoloration or slime and
  may bubble

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Updated for 2010 Edition