General

• Pyrase / BBL™ DrySlide
  Pyrrolidonyl Arylamidase (PYR) test is a rapid test which is used for the presumptive identification of group A beta-hemolytic Streptococci and Enterococci.
  
  The substrate for the PYR test is L-naphtylamide-ß-naphtylamide wich is hydrolyzed by a specific bacterial enzyme.
  
  Hydrolysis of the substrate by this enzyme releases free ß-naphtylamide, which is detected by the addition of N,N-dimethylaminocinnamaldehyde.
  This detection reagent couples with the naphthylamide to form a red Schiff base.
  
  Procedure of PYR test
  The Dryslide contain dried chromogenic substrates for pyrrolidonyl peptidase (PYRase) and beta-gluconidase.
  1. Applie only a few colonies to the test strip
  2. After 2 minutes
  3) Positive: S. pyogenes, E. faecalis and E. faecium
  
  Negative: No color change or a blue color due to a positive indole reaction.
  Group B Streptococci (Streptococcus agalactiae), Streptococcus mitis, S. bovis, S. equinus, S. milleri.
  
  Note: A pale pink reaction (weak) is considered negative.

History

Related

• Enterococcus faecium
• Enterococcus faecalis
• Streptococcus pyogenes

References

• MicrobeOnline
  https://microbeonline.com/pyrrolidonyl-arylamidase-pyr-test-principle-procedure-results/