Detection of sialidase (neuraminidase) activity in Actinomyces species by using 2'-(4-methylumbelliferyl)alpha-D-N-acetylneuraminic acid in a filter paper spot test.
A rapid method for the detection of acetylneuraminyl hydrolase, EC 3.2.1.18 (sialidase or neuraminidase), was developed by using 2'-(4-methylumbelliferyl)alpha-D-N-acetylneuraminic acid as substrate in a filter paper spot test. The method was compared to conventional assays that use 2'-(4-methylumbelliferyl)alpha-D-N-acetylneuraminic acid and bovine submaxillary mucin and was found to be in excellent agreement. Organisms with greater than 10 U of enzyme activity (in nanomoles per minute per milligram of cell protein) gave positive reactions, while those with 2.7 to 9.0 U gave only weak reactions. Isolates with less than 2.7 U of activity were detected upon prolonged incubation. Sialidase activity was detected in 79% of 71 clinical isolates representing five species of Actinomyces. The percentage of sialidase-producing isolates of each species varied considerably: Actinomyces israelii, 63%; A. meyeri, 73%; A. naeslundii, 85%; A. odontolyticus, 73%; and A. viscosus, 100%.
Moncla
B J
BJ
Department of Oral Biology, University of Washington, Seattle 98195.
Braham
P
P
D000190:Actinomyces / Q000201:enzymology*; D001431:Bacteriological Techniques; D005456:Fluorescent Dyes; D006801:Humans; D006923:Hymecromone / Q000031:analogs & derivatives; D009439:Neuraminidase / Q000032:analysis*; D014468:Umbelliferones / Q000031:analogs & derivatives
D005456:Fluorescent Dyes; D014468:Umbelliferones; D006923:Hymecromone; C021224:2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid; D009439:Neuraminidase