Science and Our Food Supply: Investigating Food Safety from Farm to Table

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MIDDLE LEVEL

MODULE 1:

 UNDERSTANDING BACTERIA

THE 12 MOST UNWANTED BACTERIA

MATERIALS

For the Class 

• 

A bowl containing the names of the 12 Most Unwanted 

Bacteria 

• 

Foods, pictures, or models of foods that contain good 

bacteria, such as cheese and yogurt 

For Each Team 

• 

A food safety portfolio for recording research data  

(use a notebook or folder) 

• 

An assortment of items for final presentations 

• 

Copy of background information for their chosen  

bacterium 

• 

Copy of The 12 Most Unwanted Bacteria reproducible  

for each student 

GETTING STARTED

ADVANCE PREPARATION

• 

Write the name of each bacterium from The 12 Most  

Unwanted Bacteria reproducible (page 29) on separate 

pieces of paper and place them in a bowl. Teams of  

students will randomly select a bacterium to study 

throughout the unit. 

• 

Copy the background material for each of the  

12 Most Unwanted Bacteria from the Food Safety  

A to Z Reference Guide. 

• 

Make one copy of The 12 Most Unwanted Bacteria  

reproducible for each student. 

• 

Collect actual foods, pictures, or models of foods that  

contain good bacteria (e.g., cheese, yogurt, etc.) 

• 

Set a due date for the final team presentations. 

INTRODUCTION

Ask students: What do you usually see 

on a “Most Wanted” list? Hopefully,  

students will respond with “bad guys” 

or “criminals.” Then hold up a copy  

of The 12 Most Unwanted Bacteria  

reproducible and ask: Does anyone 

know why these are “unwanted”? 

(They’re pathogens that can be found 

in foods and can make us sick if we  

eat them.) Distribute the reproducible. 

Continue the discussion with: 

• 

Are any of these familiar to you? Which ones? What have you heard about them? 

• 

Are all bacteria bad? (No – in fact, most bacteria are beneficial to us in our  

everyday lives.) 

• 

If I asked you to make a poster of “Wanted Bacteria,” what would you put on  

that poster? 

• 

Have you ever eaten foods that contain bacteria? 

• 

Have you ever eaten this? (Show a picture or a slice of cheese, and/or a container 

or picture of yogurt.) What do these foods have in common? (They all contain 

beneficial bacteria.) Can you think of some other foods that contain good  

bacteria? (Some examples: buttermilk, sauerkraut, pickles — even wine and beer.) 

• 

Are you surprised that these foods contain bacteria? Why? 

• 

Where else might we find good bacteria? (Examples could include: In our small 

intestine there’s generic E. coli, which helps us digest our food; and in antibiotics 

like Streptomycin, which helps treat patients with infections.) Explain to the  

class: In this activity we’re going to focus on some harmful bacteria that can  

make us sick, and explore why Dr. X considers these bacteria to be the worst — 

“the baddest of the bad!” 

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