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Just a Spider Bite?

Antimicrobial Resistance and Susceptibility


Wayne O. Hatch
Department of Biology
Utah State University Eastern


This case relates the story of two fictional college students, Kristen and Brent, who discover that they are infected with Staphylococcus aureus. Brent recovers after using an antibiotic, but Kristen does not. It is later confirmed through testing that she is infected with methicillin-resistant Staphylococcus aureus (MRSA). Students hypothesize about the difference between the two bacterial infections and the idea of antibiotic resistance is introduced. Students then use a bioinformatics tool to identify the antibiotic resistant organism. As students confirm that one bacterial infection is due to an antibiotic resistant organism, the discussion focuses on the development of antibiotic resistance. The case study is primarily designed for students in general biology courses and is particularly useful for students in microbiology. In a general biology course, it can be taught alongside evolution while, in a microbiology course, it can be used to illustrate antibiotic resistance.


  • Explore the characteristics of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA).
  • Identify the difference between antibiotic resistant bacteria and non-antibiotic resistant (susceptible) bacteria.
  • Identify how human actions, such as the production and use of antibiotics on a large scale, exert selective pressures that can influence the development of different phenotypes in a population.
  • Expose students to a bioinformatics tool by conducting a BLAST search with a given nucleotide sequence to compare to existing sequences on the NCBI website.
  • Write a short paper discussing the evolution of antibiotic resistant organisms and what strategies should be implemented to combat them in the future.


Staphylococcus aureus; methicillin-resistant Staphylococcus aureus; MRSA; infectious disease; infection; antibiotic resistance; bacterial; bacterial; horizontal gene transfer; HGT; polymerase chain reaction; PCR; BLAST; NCBI

Topical Areas

Scientific argumentation

Educational Level

High school, Undergraduate lower division, Clinical education



Type / Methods

Directed, Interrupted



Subject Headings

Biology (General)  |   Microbiology  |   Evolutionary Biology  |   Bioinformatics  |  

Date Posted


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