List of Terms: S
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Dr. Theobald Smith
Sources: Raw and undercooked eggs, raw meat, poultry, seafood, raw milk, dairy products, and produce.
Incubation: 12 to 72 hours after eating contaminated food.
Symptoms: Diarrhea, fever, and abdominal cramps. Symptoms can be more severe and cause death among people in the at-risk groups.
Duration: 4 to 7 days.
More on Salmonella Enteritidis and Salmonella Typhimurium:
- There are approximately 2,000 different serotypes of Salmonella bacteria. Salmonella serotype Typhimurium and Salmonella serotype Enteritidis are the most common in the United States.
- Most types of Salmonella live in the intestinal tracts of animals and birds and are transmitted to humans by contaminated foods of animal origin. Salmonella Enteritidis can silently infect the ovaries of healthy-appearing hens and contaminate the eggs before the shells are formed (also see Competitive Exclusion).
- Salmonella Typhimurium DT104 is an emerging pathogen and a highly virulent strain of Salmonella that is resistant to several antibiotics. This organism is now the second most prevalent strain of Salmonella after Salmonella serotype Enteritidis.
A specimen that is taken from food and tested for the purpose of identifying a foodborne pathogen or various kinds of chemical contaminants in food.
The act of maintaining a clean condition in a food-handling situation in order to prevent disease and other potentially harmful contaminants.
Chemical or physical agents that reduce microorganism contamination levels present on inanimate environmental surfaces.
Food Safety Implication: Using hot, soapy water is sufficient for cleaning food-contact surfaces, cutting boards, utensils, etc. Periodically, kitchen sanitizers can be used for added protection against bacteria. Sanitizers help kill bacteria, so that bacteria doesn't spread to food.
Two Classes of Sanitizers:
- Sanitizers of Non-Food Contact Surfaces - Traditionally, the performance standard used by the Environmental Protection Agency (EPA) for these sanitizers has required a reduction of the target microorganism by 99.9% or 3 logs (1000, 1/1000, or 103) after 5 minutes of contact time.
- Sanitizing Rinses for Previously Cleaned Food-Contact Surfaces - Traditionally, the EPA performance standard for these sanitizers has required a 99.999% or 5-log (105) reduction of the target microorganism in 30 seconds. (SeeLog Reduction.)
Disinfectants: In comparison, disinfectants come in a variety of categories and are also agents that help eliminate undesirable microorganisms from inanimate environmental surfaces. Because these surfaces are inanimate, they are considered contaminated, not infected. Measurement of disinfectant performance varies by product type (spray, dilution product, impregnated wipe, etc.).
Disinfectant performance is typically not defined in terms of a specific percentage or log-reduction target, and unlike the sanitizers for food-contact surfaces, products that are termed disinfectants are usually not intended for use in association with food-contact surfaces.
Note: Read and follow label directions to determine the specific microorganism a product kills and how to use the product effectively. Sanitizers and disinfectants must remain in contact with a surface for a specified period of time in order to kill organisms. Be sure to check the label.
> Satellite Tracking (also known as Satellite Monitoring)
Equipment that automatically records refrigeration system functions and the air temperature inside refrigerated containers that transport foods across the country. This information provides a detailed record of the refrigeration system's performance during the trip.
Food Safety Implication: To avoid the risk of food spoilage and microbial growth during shipment, satellite tracking monitors the temperature inside refrigerated containers.
> "Sell By" Date
A calendar date on the packaging of a food product that indicates the last day the product can be sold.
The "sell by" date tells the retailer how long to display a product. It guides the rotation of shelf stock and allows time for the product to be stored and used at home. The date is quality driven, not a food safety concern. (Also see "Best If Used By," Expiration, and "Use By" Dates.)
A sub-species classification system that uses serum (the clear, yellowish liquid that separates from the clot when blood coagulates) from immunized animals to distinguish between bacterial isolates that belong to the same genus and species.
Food Safety Implication: For outbreak analysis, serotyping serves as a fast, easy method for classifying bacterial isolates for the purpose of comparing strains recovered from foods, patients, and the environment. It also helps epidemiologists determine if a foodborne illness is an isolated occurrence or part of an outbreak.
How It Works: Each bacterial strain elicits a specific immune response when it is introduced into an animal. A bacterium expresses specific proteins and carbohydrates on its surface to which antibodies may react.
Public health scientists have assembled a specific set of antibodies that react with certain bacteria. The profile of which serum/ sera the bacterial isolate reacts with is called its serogroup or serotype. Groups of bacteria that react to a certain antibody are considered to be members of that serogroup.
> Shelf Stable
A food that is able to be stored un-refrigerated on the shelf for a period of time and remain suitable for consumption.
Food Safety Implication: Many foods are processed and packaged for food safety and preservation purposes. In order for food to be considered shelf stable, the various techniques used should inhibit microorganisms from growing in the product at non-refrigerated temperatures of storage (extended periods over 41° F [4° C]).
An Example of Shelf-Stable Foods
Some Shelf-Stable Foods Include:
- Canned vegetables,
- Cookies fruits, and juices
- Canned meat
This bacterium is carried only by humans and causes an estimated 448,420 cases of diarrheal illnesses in the United States per year. Poor hygiene, especially improper handwashing, causes Shigella to be easily passed from person to person via food. Once the bacterium is in the food, it multiplies rapidly at room temperature.
Sources: Salads, milk and dairy products, raw oysters, ground beef, poultry, and unclean water.
Incubation: 1 to 7 days after eating contaminated food.
Symptoms: Diarrhea, fever, abdominal cramps, vomiting, and bloody stools.
Duration: 5 to 7 days.
A thick-walled protective structure produced by certain bacteria and fungi to protect their cells.
Spores like these are found everywhere
in the environment, including in foods.
Food Safety Implication: Some spores can germinate into pathogenic bacteria, such as the highly potent Clostridium botulinum, which is primarily a threat in improperly canned foods and can cause botulism. Other spore-forming pathogens include Clostridium perfringens and Bacillus cereus. These pathogenic bacteria can cause foodborne illness when the contaminated food is eaten.
In addition, some spores often survive cooking, freezing, and some sanitizing measures. For example, the spores of certain bacteria can survive boiling for 6 hours. When conditions are favorable for bacterial growth, the spore will germinate and the bacterial cell will divide.
> Staphylococcus aureusThis bacterium is carried on the skin and in nasal passages of humans and often found in infected cuts and burns. These wounds should always be covered with a water-proof bandage or plastic gloves to avoid contact with food. Staphylococcus aureus produces a toxin that causes vomiting in as little as 30 minutes after ingestion. It also multiplies rapidly in food that's left out at room temperature.
Sources: Dairy products, salads, cream-filled pastries and other desserts, high-protein foods, such as cooked ham, raw meat and poultry, and humans (skin, infected cuts, pimples, noses, and throats).
Incubation: Usually rapid - within 30 minutes to 8 hours after eating contaminated food.
Symptoms: Nausea, abdominal cramps, vomiting, and diarrhea.
Duration: 24 to 48 hours.
A variant of a species of bacteria. Some may be pathogenic and some may be benign. For example, most E. coli are neutral or helpful to people, but E. coli O157:H7 is a strain of E. coli that is harmful to people.
A system of monitoring the health of the population, which is used to prevent food-borne illness outbreaks from increasing.
Food Safety Implication: By monitoring the health of the population, foodborne illness can be reduced by recognizing outbreaks and responding to them. This can be done by determining the source, eliminating the source, and preventing the spread of illness by infected individuals.
A tool used by epidemiologists to understand the state of health of the population or to identify the source of a foodborne outbreak.
Food Safety Implication: Epidemiologists actively "survey" (seek out) individuals to see if they are sick or well. If people are suspected of being sick from food, then epidemiologists will survey sick and well people to determine what they ate. The results of the survey should implicate a specific food, location, or time of consumption.