Question

10. describe results from a coagulase, dnase, and novobiocin test that would suggest a mixed culture was used for the tests, as opposed to a pure culture.

Answer 1

A positive result in a coagulase test indicates the presence of coagulase-positive species in a mixed culture, while a positive result in a dnase test suggests the presence of species capable of DNA hydrolysis. A resistant result in the novobiocin test suggests the presence of Staphylococcus saprophyticus.

Step-by-step explanation:

In a coagulase test, if the result is positive, it suggests the presence of coagulase-positive species like Staphylococcus aureus. If the result is negative, it suggests the presence of coagulase-negative species like Staphylococcus epidermidis.

In a dnase test, if the result is positive, it suggests the presence of species that can hydrolyze DNA, indicating the presence of mixed culture. If the result is negative, it suggests the absence of DNA-hydrolyzing species.

In a novobiocin test, if the result is resistant, it suggests the presence of Staphylococcus saprophyticus, which is a coagulase-negative staphylococcus. If the result is susceptible, it suggests the absence of Staphylococcus saprophyticus.