What is a PYR test?

The correct answer to this question is PYR Positive. PYR stands for pyrrolidonly Aminopeptidase. This test is used to detect the activity of pyrolidonly arylamidase activity. This activity appears in Streptococcus pyogenes (also known as Group A strep), Enterobacteriaceoa, and Enterococcus. It can also be used to identify E. Coli.

Using the broth method, the PYR test takes about 4 hours and the disk method takes about 10 to 15 minutes. As shown in this image, it is positive because a cherry red color has developed. If the result was negative, the test would be a yellow or orange color.