Microorganisms C 5.01 -- Microbiology

Microbiology Microorganisms are everywhere. Microbiology is the study of microorganisms—living organisms too small to be seen by the naked eye without magnification. C 5.01 -- Microbiology

Three Roles of Microorganisms Pathogens -- cause foodborne illness. Spoilers -- cause food to spoil and decrease its shelf-life. Beneficial -- used for food fermentation and are naturally present in and on the body. C 5.01 -- Microbiology

Contaminated Food Microorganisms can contaminate any food: naturally or through improper food handling Contaminated food can cause foodborne illness or food spoilage. Measures must be implemented to control for: Food safety – preventing foodborne illness and Food quality – maximizing shelf-life C 5.01 -- Microbiology

Pathogens Foodborne illness Foodborne illness outbreak An illness caused by eating contaminated foods or beverages.  Foodborne illness outbreak the occurrence of two or more cases of a similar illness resulting from eating a common food. Each year there are: 76 million cases of foodborne illness 323,914 hospitalizations 5,194 deaths C 5.01 -- Microbiology

Spoilers Cause the deterioration of food, such as sour milk or lunch meat turning slimy. Eating spoiled food does not usually cause illness. Food spoils because of microbial growth or enzymatic activity. C 5.01 -- Microbiology

Beneficial Beneficial microorganisms are not contaminants – they are naturally present or are intentionally added to foods. Primary purposes: Health benefits – naturally present on skin and in the intestinal tract. New food products – use for food fermentation to create new products. Yogurt Sour dough culture C 5.01 -- Microbiology

Five Major Groups of Microorganisms Bacteria Viruses Parasites Mold Yeast PHOTOGRAPH CREDITS: Ralph Van Dyke Jr. The Des Moines University Osteopathic Medical Center Des Moines, Iowa 50317 USA Email: rvandykejr3@mchsi.com This strain of Bacillus cereus was isolated from a sample of gasoline-contaminated soil and cultured on blood agar during the Summer Microbiology Practicum at the Des Moines University, Iowa. Spores were present after 3 days, however, this picture was taken 1 week after culture. Endospores are extremely hardy bacterial structures that contain the organism genome. Endospores remain viable through many extreme conditions, such as common cooking techniques. Endospores can be destroyed by proper pressure canning or pressure cooking. B. cereus can cause severe food poisoning with a short incubation period. A common source can be fried rice made from unrefrigerated cooked rice. Short incubation B. cereus food poisoning can be mistaken for staphylococcal food poisoning. This picture allows students to see spores utilizing a simple, reliable method of staining. C 5.01 -- Microbiology

Bacteria Basics Invisible to the naked eye. Pathogens, spoilers, and beneficial. Grow in food. Some produce spores. Some produce toxins. Not necessarily destroyed by freezing or cooking. Bacillus cereus C 5.01 -- Microbiology

Virus Basics Invisible to the naked eye. Pathogens -- not spoilers or beneficial. Do not grow in food; use food as a vehicle to get from one person to another Can contaminate any food Cause most foodborne illnesses in the U.S. Usually destroyed by cooking but not freezing. Norovirus C 5.01 -- Microbiology

Parasite Basics Some are visible to the naked eye Pathogens – not spoilers or beneficial. Do not grow in food Found naturally in many animals pigs cats rodents, and Seafood Destroyed by proper freezing and cooking. Anisakis simplex C 5.01 -- Microbiology

Mold Basics Visible to the naked eye. While most spoil food, some are pathogenic and some beneficial. Some form toxins that can cause illness. Grow in a wide range of foods – high acid, low moisture. Requires air to grow Freezing does not destroy. C 5.01 -- Microbiology

Yeast Basics Visible to the naked eye. Spoilers and beneficial but not pathogenic. Grow in a wide range of foods – high acid, low moisture. Produce a smell, bubbling, or a taste of alcohol when food spoils Easily destroyed by proper processing. C 5.01 -- Microbiology