PYR BROTH

PYR hydrolysis is a presumptive test for both group A and group D enterococcal streptococci. The PYR test determines the activity of enzyme L-pyrrolidonyl arylamidase (PYR) produced by Streptococcus pyogenes but not by other ?-haemolytic streptococci. Free b-napthylamide is then detected by addition of the diazo dye complex, N,N dimethylaminocinnamaldehyde. Development of a red colour is indicative of PYR hydrolysis. PYR test is a highly sensitive test, which replaces bacitracin and salt tolerance (growth in 6.5% NaCl) tests. PYR Broth is recommended for detection and presumptive identification of S. pyogenes based on PYR hydrolysis. Todd Hewitt Broth Base acts as the basal medium to which the agar and substrate for PYR enzyme is added.

for the isolation and identi?cation of Streptococcus pyogenes