Microbiology: A Systems Approach 4th Edition by Marjorie Kelly Cowan

Exercise 42

A friend was recently diagnosed with strep throat. One week after his treatment, he redeveloped the infection. In conversation, your friend tells you, "I must have become immune to the drug the doctor gave me!"
a. Discuss the validity of your friend's statement, providing evidence in support of or refuting his claim.
b. After further conversation, your friend tells you that he stopped taking his initial antibiotics after 2 days because he "felt 100% better." Explain how this action might have played a role in the redevelopment of his infection.
c. When he returned to his physician, she ordered a test to determine which antibiotic should be prescribed to treat his reinfection. Summarize a test that could be used to obtain this information.