High School Food Safety Lessons
Health Education Standards
1B Bacteria Everywhere
(grades 9-11) 1:1, 1:5
- Emphasize with students that bacteria are
everywhere and can spread from surface to surface, person to
person, food to food, and person to food. Explain to students that
bacteria can be controlled by practicing what is called the 4Cs
of Food Safety—Clean, Cook, Chill, and Combat Cross-Contamination.
- Reinforce with students that not all bacteria are harmful;
most bacteria are beneficial—and give some examples (see
page 6 of Food
Safety A to Z Reference Guide).
“Today you are going to look at how
the bacteria have grown in your Petri dishes and record the results.
You can turn over your Data
Table Sheet and illustrate the organisms that are growing.”
- Help students to analyze the results of their experiments.
- Use a scale of 0-5 to enumerate the number of colonies you
- State the size, shape, and colors of the organisms and record
on the Data Table Sheet.
- Why do the microorganisms look different?
- How can the different
strains of bacteria be identified (by colony morphology)?
Place one of the Petri dishes on an overhead projector and discuss
“How do you know the agar and swabs used to collect samples were free
from micro-organisms?” (Make a control plate.) If agar and
swabs were contaminated, discuss how this would affect the results.
- “What do the data you have collected have to do with
food you eat?” (Bacteria can be transferred from surface
to food and from hands to food.)
- “Why do certain surfaces produce
more bacterial growth than
others?” (It depends on moisture, temperature, pH.)
All bacteria are not bad; in fact, most are beneficial (again,
- Ask the students:
“How can bacteria be transferred from objects to foods, from people
to foods, and from food to food?” (Contact with contaminated
objects, hands, other foods)
- Why is it important to more thoroughly
clean some surfaces than others? (Bacteria thrive
in some areas more than others.)
- How should surfaces be cleaned?
- What advice do you have for restaurant workers and fast-food
|Share with the students:
“This laboratory lesson continues to reinforce understanding
of different strains of bacteria and how these strains can be identified
colony morphology. It also reinforces our knowledge about how bacteria
can be spread from surface to surface, from person to person, and
from food to food. The simple rules that we can all remember is:
Clean, Cook, Chill, and Combat Cross-Contamination. In our next lesson
we will discover the 12 most unwanted bacteria—or pathogens
(a pathogen is any micro-organism that is infectious and causes disease).”
|Seek school personnel cooperation by:
- Asking the librarian to place Dr. X and the Quest for Food
Safety video on reserve so that students can review Module 1,
- Asking the English department to encourage
students from this class to prepare a report discussing the effects
the 4Cs have on bacteria.
Explain that students should cover Cleaning (removes bacteria
from hands and surfaces, Cooking (heat kills bacteria by breaking down
their cell walls), Chilling (slows down the bacteria's metabolism
thus slowing growth), and Combatting Cross-Contamination (prevents
the spread of bacteria from one object to another).
- Ask a microbiologist,
surgeon, hospital dietician, school cafeteria director, emergency
room physician, meat-packing employee, or
milk processing plant employee to discuss their work with your class as
a reinforcement of the concepts learned. Be certain to inform
the speaker about the level of student insights gained from the two laboratory
lessons, and the relationships drawn to food safety, so the speaker
can explain how he/she controls the spread of harmful bacteria.
classroom or school library with a copy of Food
Service Education: Community Service Learning Curriculum. A
Program Using the Community Service Learning Model to Teach
Youth Food Safety, Volumes I
and II (Project Team: Lori Pivarnik, Ph.D., Co-Principle Investigator,
Martha Smith-Patnoad, Co-Principle Investigator) University of
Rhode Island, Department of Food Science and Nutrition Cooperative Extension.
This program was designed for Extension educators and their
to provide training and support for FCS teachers who want to
integrate food safety
based community service learning into existing programming. The
educator provides 6-8 hours of training for the teachers with
an emphasis on food safety principles and on the community service
Please refer especially to Teacher Information sheets 1-9, Teacher
Fact Sheets pages 52-78, and Student Activity #1, #2, and #3 (page
79-91), which are especially related to these lessons.
Provide students with the following resources and websites:
- The Microbe
Zoo: Digital Learning Center for Microbial Ecology
at Michigan State University/Comm Tech Lab www.comtechlab.msu.edu/sites/dlc-me/zoo/
are Germs? Kids Health www.kidshealth.org/kid/talk/qa/germs_prt.htm
Do I Need to Wash My Hands? Kids Health www.kidshealth.org/kid/talk/qa/wash_hands_prt.htm
- It's a SNAP. Centers for Disease Control and Soap and Detergent