Thermo Scientific™ PYR/Esculin Disc

Description

• Rapidly, presumptively identify Group A streptococci and enterococci using reagent-impregnated Thermo Scientific™ Remel™ PYR/Esculin Disk
• Ellner et al
• described a colorimetric method for the PYR test using filter paper strips containing PYR substrate 1
• Using a rapid spot test, Edberg et al
• demonstrated the hydrolysis of esculin to esculetin by utilizing the loss of fluorescence as an indicator of esculin hydrolysis 2
• In 1981, Godsey et al
• described a test to differentiate group A streptococci and enterococci from other streptococci based on their ability to cleave L-pyrrolidonyl-β-naphthylamide (PYR) 3
• In 1982, Facklam et al
• used PYR test in conjunction with the CAMP and esculin hydrolysis tests to presumptively identify streptococci 4,5
• Ready to use - L-pyrrolidonyl-β-naphthylamide-impregnated disk Easy to interpret - With visual inspection The enzyme pyrrolidonyl peptidase hydrolyzes the substrate L-pyrrolidonyl-β-naphthylamide (PYR) to produce β-naphthylamine
• Following addition of N,N-dimethyl-aminocinnamaldehyde (PYR reagent) a red color is formed
• Escuin is hydrolyzed at the β- glucose linkage to yield two products – esculetin and glucose
• Esculin fluoresces under ultraviolet light at 360 nm, whereas the hydrolysis product esculetin fails to fluoresce
• Both reactive substrates, PYR and esculin, are lyophilized in disk form for stability.