Thermo Scientific™ Enterococcus/Group A Strep Screen

Description

• Presumptively identify Group A Streptococci and Enterococci using Thermo Scientific™ Remel™ Enterococcus/Group A Strep Screen
• Rochaix first demonstrated the value of esculin hydrolysis in the identification of enterococci 1
• In 1970, Mulczyk and Szewczuk described the L-pyroglutamic acid β-naphthylamide (PYR) hydrolysis test 2
• These combinations of tests were useful in the identification of Streptococcus pyogenes , Enterococcus species, and other gram-positive cocci 3
• Presumptively identify Group A Streptococci and Enterococci using Enterococcus/Group A Strep Screen
• Easy to store - No special storage required Easy to interpret - With visual inspection - the color change in the medium to dark brown indicates a positive esculin reaction and after addition of two drops of Cinnamaldehyde Reagent to the tube, the color changes to red indicating a positive PYR test
• This medium contains esculin compound which is hydrolyzed enzymatically at the β-glucose linkage to yield two products – esculetin and glucose
• Esculetin reacts with the ferric ammonium citrate present in the medium to form a phenolic iron complex which is brown-black in color
• L-pyroglutamic acid β-naphthylamide (PYR) serves as the substrate for the detection of pyrrolidonyl peptidase
• Following substrate hydrolysis by the peptidase enzyme, the resulting β-naphthylamine produces a red color upon the addition of ρ-dimethyl-aminocinnamaldehyde (Cinnamaldehyde Reagent).