Microbiology Experiments: A Health Science Perspective 8th Edition by John Kleyn, Samuel Certo, Anna Oller

Exercise 8

You test a clinical specimen of Streptococcus with the antibiotics penicillin and tetracycline. The zones of inhibition for penicillin and tetracycline are both 20 mm. What does this tell you about comparing zone sizes and the use of the antibiotic zone diameter chart? Is this organism sensitive to both of these antibiotics?