The algorithm shown indicates bacitracin sensitivity for only one group of Gram-positive cocci.Why is bacitracin sensitivity NOT tested in all of the cases shown?

Question

Quizplus · Accepted Answer

Bacitracin sensitivity is only tested in group A beta-hemolytic streptococci because all of them are known to be susceptible to it. Testing for bacitracin sensitivity in nonhemolytic and alpha-hemolytic bacteria is not necessary, as they are only susceptible to optochin. Thus, option B is the correct choice. Option A is incorrect as there is no information given to suggest that testing antibiotic sensitivity in nonhemolytic streptococci is time-consuming. Option C is incorrect as not all beta-hemolytic streptococci are susceptible to bacitracin. Option D is incorrect as only alpha-hemolytic streptococci are susceptible to optochin, while nonhemolytic bacteria are not usually tested for susceptibility to this antibiotic.

The Algorithm Shown Indicates Bacitracin Sensitivity for Only One Group