Servsafe Chapter 2 5x3ga

Learning Objectives Define key : Microorganisms, Pathogen, Toxin, Spoilage Microorganisms  Differentiate the types of pathogens  Describe the growth curve of bacteria  Enumerate the conditions of the growth microorganisms 

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

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Carried by food, water, humans and insects



Can reproduce rapidly



Some survive freezing



Some form spores

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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)

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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 

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

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

DIAGRAMATIC SCHEME FOOD SAFETY HAZARDS Physical

Infection

Bacteria

Viruses

Intoxication

Toxin-Mediated Infection

Salmonella

Staphylococcus aureus

Bacillus cereus (diarrheal)

Listeria monocytogenes

Clostridium botulinum

Shigella spp.

Vibrio spp.

Bacillus cereus (emetic)

Clostridium perfringens

Campylocacter jejuni Yersinia enterocolitica

Escherichia coli 0157H7

Biological

Chemical

Fungi Molds (including mushrooms)

Parasites

Directly Added

Indirectly Added

Food Allergens

Naturally Occuring

Yeasts Food Additives Flavors

Cleaning Chemicals

Seafood Toxins

Colors

Pesticides

Plant toxins

Preservatives

Heavy Metals

Fungal Toxins

Antibiotics

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

Major Foodborne Illnesses Caused by Bacteria 

Bacillus cereus gastroenteritis

Listeriosis

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Botulism

Staphyloccocal food poisoning

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Campylobacteriosis

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E. coli O157:H7 EHEC



Vibrio gastroenteritis



Yersiniosis



Salmonellosis



Shigellosis

  

Clostridium perfringens Enteritis

Figure 21.2

Egg sizes

Egg Grades

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

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Can’t reproduce outside a living cell

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Usually contaminate food through poor personal hygiene

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May survive freezing and cooking

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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

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Cook to proper temperatures

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Avoid cross-contamination

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Use sanitary water supplies

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Wash hands properly

Major Foodborne Illnesses Caused by Parasites 

Trichinosis

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Anisakiasis

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Giardiasis

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Toxoplasmosis

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Intestinal Cryptosporidiosis

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Cyclosporiasis

Major Foodborne Illnesses Caused by Parasites Trichinosis 

also called trichinellosis, or trichiniasis, is a parasitic disease caused by eating raw or undercooked pork or wild game infected with the larvae of a species of roundworm Trichinella spiralis, commonly called the trichina worm.

Major Foodborne Illnesses Caused by Parasites Anisakiasis 

is a genus of parasitic nematodes, which have a life cycle involving fish and marine mammals.

Major Foodborne Illnesses Caused by Parasites Gardiasis 

(discovered by DR James de Silva) in humans is a diarrheal infection of the small intestine by a single-celled organism called Giardia lamblia.

Giardiasis

occurs worldwide with a prevalence of 20–30% in developing countries.

Giardia lamblia cell

Major Foodborne Illnesses Caused by Parasites Toxoplasmosis 

is a parasitic disease caused by the protozoan Toxoplasma gondii.

Up

to one third of the world's human population is estimated to carry a Toxoplasma infection.

Ingestion

of raw or partly cooked meat, especially pork, lamb, or venison containing Toxoplasma cysts.

Protozoan T. gondii

Major Foodborne Illnesses Caused by Parasites Intestinal Cryptosporidiosis 

also known as crypto, is a parasitic disease caused by Cryptosporidium, a protozoan parasite.

It

affects the intestines of mammals and is typically an acute short-term infection. It is spread through the fecal-oral route, often through contaminated water

Cryptosporidium muris

Major Foodborne Illnesses Caused by Parasites Cyclosporiasis is

an infection with the protozoan Cyclospora cayetanensis, a pathogen transmitted by feces or feces-contaminated fresh produce and water.

Outbreaks

have been reported due to contaminated raspberries. It is not spread from person to person.

It

can be a cause of diarrhea for travelers.

Cyclospora cayetanensis

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.

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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.