title: Modified taurocholate-tellurite-gelatin agar for improved differentiation of Vibrio species.
abstract: A total of 78 strains, representing 21 Vibrio species, were examined by using taurocholate-tellurite-gelatin agar (TTGA) medium and modified TTGA medium containing 4-methylumbelliferyl-beta-D-galactoside (150 micrograms/ml). Modified TTGA medium allowed for simple and direct detection of beta-D-galactosidase (beta-gal) activity. This feature, in conjunction with other differential characteristics of TTGA medium, gave improved differentiation of the vibrios tested. The modified TTGA medium allowed for easy differentiation of Vibrio cholerae (beta-gal+) from Vibrio parahaemolyticus (beta-gal-). The 4-methylumbelliferyl-beta-D-galactoside substrate is inexpensive and very stable. Incorporation into the agar did not affect the performance of TTGA as a differential medium. The assay for beta-gal activity with this substrate was specific and sensitive.
mesh_terms: D000362:Agar; D005697:Galactosides; D005780:Gelatin; D006801:Humans; D006923:Hymecromone / Q000031:analogs & derivatives; D013045:Species Specificity; D013656:Taurocholic Acid; D013691:Tellurium; D014733:Vibrio / Q000145:classification / Q000201:enzymology / Q000302:isolation & purification*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D005697:Galactosides; D006923:Hymecromone; D013656:Taurocholic Acid; C026845:4-methylumbelliferyl-galactopyranoside; D005780:Gelatin; D000362:Agar; D001616:beta-Galactosidase; C026660:tellurous acid; D013691:Tellurium