The Pyrrolidonyl Arylamidase (PYR) test is a fast test used to identify group A beta-hemolytic streptococci and enterococci. Escherichia coli (-ve) is also identified using the PYR test, which distinguishes it from other indole-positive, lactose-positive, Gram-negative rods. It is also known as PYR (L-pyrrolidonyl—naphthylamide) and serves as a substrate for pyrrolidonyl peptidase detection. L-Pyrrolidonyl- -naphthylamide … Read more