Pyroglutamate test for pyrrolidonyl arylamidase

The pyroglutamate test for pyrrolidonyl arylamidase ( pyrrolidonyl arylamidase test or PYR test ) is a method for the rapid colorimetric determination of certain groups of bacteria on the basis of the activity of the enzyme pyrolidonyl arylamidase . L-pyroglutamic acid beta-naphthylamide is impregnated in the test plate and serves as a substrate for the detection of pyrolidonyl arylamidase. The hydrolysis of the substrate leads to the formation of beta-naphthylamide, which combines with the PYR reagent (p-dimethylamino-cinnamaldehyde) and forms a light pink to cherry red color. A positive PYR test allows the detection of streptococci of Lancefield group A ( esp . Streptococcus pyogenes ) and enterococci .

As an alternative, serological tests are available for the Lancefield group to differentiate enterococci from Streptococcus agalactiae .

literature

• Cornela Waibel: Investigations into the applicability of the "Matrix-assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometry" technique for the identification of clinically relevant, coryneform bacteria. (pdf) Dissertation to obtain a doctorate in medicine from the Medical Faculty of Ulm University, 2012.

Web links

• BD CHROMagar Orientation Medium / Columbia CNA Agar (Biplate). bd.com

credentials

1. ^ RR Facklam, LG Thacker, B. Fox, L. Eriquez: Presumptive identification of streptococci with a new test system. In: Journal of Clinical Microbiology . tape 15 , no. 6 , January 6, 1982, p. 987-990 , PMID 7050157 .
2. ↑ LP Gordon, MA Damm, JD Anderson: Rapid presumptive identification of streptococci directly from blood cultures by serologic tests and the L-pyrrolidonyl-beta-naphthylamide reaction. In: Journal of Clinical Microbiology . tape 25 , no. 2 , January 2, 1987, p. 238-241 , PMID 3546362 .