Introduction

Microorganisms are small, living organisms that can only be seen by microscope.

Pathogens are microorganisms that cause illness.

The consumption of food with toxins (poisons) is the leading cause of foodborne illness.

What are Germs?

Germs are microorganisms that are likely to cause disease

Microorganisms are found throughout the environment. Onlya very small number are pathogenic, i.e. capable of causing disease, and not all diseases are caused by microorganisms

Some bacteria live in our gut and help to digest food.Some yeasts and bacteria are used in baking, brewingor cheese making

Bacteria are just one type of micro-organism, alongside viruses, fungi and protozoa

4 Organisms that contaminate food and cause foodborne illness

Food

Acidity

Temperature

TimeOxygen

Moisture

Conditions that favor growth of foodborne microorganisms

Bacteria

Living, single celled organism Carried by food, water, soil, animals,

humans, insects Can survive freezing temps Can cause food spoilage and illness Can change form to protect themselves

when nutrients are unavailable - spores

Bacteria Bacteria are prokaryotes and have a characteristic cellular

organisation. They are simple, small, unicellular organisms, varying in size between 1-20 um long

Bacteria can be classified by shape:

Spherical (coccus)e.g. Staphylococcus aureus

Rod (bacilli)e.g Escherichia coli

Spiral/helicale.g. Treponema

Salmonella•Carried naturally by many farm animals•Illness can occur from consuming only a small amount of contaminated food

Listeriosis (Listeria)•Naturally found in soil, water, and plants•Grows in cool, moist environments•Pregnant women are especially vulnerable

Staphylococcal Gastroenteritis

•Primarily found in the hair, nose, throat, and sores of humans•Cooking cannot destroy these toxins•Practice good hygiene!

Botulism•Bacteria is found commonly in produce grown in the soil•Grows without oxygen and produces a deadly toxin•Without treatment, can cause death

Hemorrhagic Colitis•Caused by and more commonly referred to as E.Coli poisoning•Produced toxins in the intestines•Can be present in feces of infected persons for several weeks after symptoms appear

Viruses The smallest of microbial contaminants Cannot reproduce in food, but will produce

more viruses once in a human cell Can be transmitted from person to person,

people to food, and people to food-contact surfaces

Usually contaminate through a foodhandler’s improper hygiene

Classified as infections 2 major viral foodborne illnesses: Hepatitis

A and Norovirus

Hepatitis A•An infected person may not show symptoms for several weeks, but can be very infectious•Found primarily in feces of those infected•Cooking does not destroy the virus

Norovirus•Very contagious virus•Like Hepatitis A, it is transferred by touching food with fingers containing feces

Parasites

Living organisms that need a host to survive

Larger than bacteria, yet still microscopic

Typically passed to humans through animal host (cows, chickens, pigs, fish)

Anisakiasis•Worm like parasite found in fish and shellfish•Critical to cook seafood properly

Fungi

Found naturally in air, soil, plants, water, and some food.

Examples: mold, yeast, mushrooms

Types of FungiMolds

Responsible for spoilage of food Results in odors, discoloration, and off

flavors – alcohol scent or flavor Prefer to grow in and on acidic food

with low water activity Aflatoxin – produced by molds and

can cause liver disease Corn products, peanut products,

tree nuts Throw away molded foods to prevent

illness FDA recommends cutting away at

least one inch areas around moldy hard cheeses

Yeast Ability to spoil food rapidly Produces carbon dioxide and alcohol May appear slimy, produce bubbles,

and have a pink discoloration Food spoiled by yeast should be

discarded. Found in jellies, jams, honeys, syrups,

and fruit juice