Coagglutination and enzyme capture tests for detection of Escherichia coli beta-galactosidase, beta-glucuronidase, and glutamate decarboxylase.
Polyclonal antibodies to Escherichia coli beta-galactosidase, beta-glucuronidase, and glutamate decarboxylase were used in coagglutination tests for identification of these three enzymes in cell lysates. Enzyme capture assays were also developed for the detection of E. coli beta-galactosidase and beta-glucuronidase. The enzymes were released by using a gentle lysis procedure that did not interfere with antibody-enzyme interactions. All three enzymes were detected in 93% (51 of 55) of the E. coli strains tested by coagglutination; two of the three enzymes were identified in the remaining 7%. Of 42 non-E. coli tested by coagglutination, only four nonspecifically agglutinated either two or three of the anti-enzyme conjugates. Thirty-two (76%) non-E. coli isolates were negative by coagglutination for all three enzymes. The enzyme capture assay detected the presence of beta-galactosidase in seven of eight and beta-glucuronidase in all eight strains of E. coli tested. Some strains of beta-galactosidase-positive Citrobacter freundii and Enterobacter cloacae were also positive by the enzyme capture assay, indicating that the antibodies were not entirely specific for E. coli beta-galactosidase; however, five other gas-positive non-E. coli isolates were negative by the enzyme capture assay. The coagglutination tests and enzyme capture assays were rapid and sensitive methods for the detection of E. coli beta-galactosidase, beta-glucuronidase, and glutamate decarboxylase.
D000372:Agglutination Tests; D004926:Escherichia coli / Q000201:enzymology*; D005696:Galactosidases / Q000032:analysis*; D005966:Glucuronidase / Q000032:analysis* / Q000276:immunology; D005968:Glutamate Decarboxylase / Q000032:analysis* / Q000276:immunology; D007124:Immunoenzyme Techniques; D001616:beta-Galactosidase / Q000032:analysis* / Q000276:immunology
D005696:Galactosidases; D001616:beta-Galactosidase; D005966:Glucuronidase; D005968:Glutamate Decarboxylase