Medical Assistant Students Breed Bacteria to Educate Third Graders

How clean is your kitchen? Are your cleaning products leaving harmful bacteria behind?

micro1Medical assistant students in the Microbiology class at Globe University-Madison East recently posed those questions to third graders at Cottage Grove Elementary School. The medical assistant students visited the third graders to discuss how bacteria can live on surfaces, how contact with these surfaces can cause illness and how to disinfect surfaces to prevent the transfer of bacteria and food-borne illness.

The third graders acted as scientists, using scientific method to perform an experiment comparing the effectiveness of various disinfectants on surfaces that have contacted raw meat. They formed a hypotheses and conducted experiments to answer these questions.

Each medical assistant student worked with a pair of third graders to collect bacterial cultures from a contaminated surface with or without various disinfection methods including:

  • lemon juice and baking soda
  • soap
  • cleaning wipes
  • vinegar
  • bleach
Medical assistant student Jenny Zeimet works with two of the third graders.


A week later the medical assistant students returned to the third grade class with the bacterial plates and photos of the growing bacteria. The third graders were able to observe the amount of bacteria growing on the plates through microscopes and compare the appearance and the amount of bacteria that grew after various methods of disinfection.

As expected, disinfecting the contaminated surfaces resulted in fewer bacterial colonies than the control, which received no disinfectant. The most effective disinfectant was bleach, followed by cleaning wipes, vinegar, lemon juice/baking soda, and soap.

“We were impressed by the third graders’ knowledge of how to avoid food poisoning and their enthusiasm for learning more about how microorganisms cause food-borne illnesses,” said Medical Assistant Instructor Michelle Cotroneo. “The medical assistant students loved working with them!”

Through this project, the medical assistant students were able to apply the knowledge learned in their Microbiology class, as well as use their patient education skills, to work with the children.