Efficacy of beta-glucuronidase assay for identification of Escherichia coli by the defined-substrate technology.
In 1976, Kilian and Bulow described the association of beta-glucuronidase with the genus Escherichia (97% positive) and suggested that a beta-glucuronidase assay would be a useful identification test. Since that report, papers about the sensitivity and specificity of this enzyme for the identification of Escherichia coli from clinical sources, food, seawater, potable-water supplies, and various environmental sources have appeared. A study was undertaken to determine the efficacy and specificity of the defined-substrate technology beta-glucuronidase (Colilert) assay for the identification of this species from fecal samples. A total of 460 human, 105 cow, and 55 horse E. coli isolates were tested. Results showed 95.5% beta-glucuronidase-positive isolates in 24 h and 99.5% positive after 28 h of incubation. Only one E. coli isolate was negative. There were no significant differences in the percentage of beta-glucuronidase-positive isolates among the human or animal isolates. There were no non-E. coli isolates that were positive. All subjects carried beta-glucuronidase-positive E. coli.
Risk Reduction Engineering Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268.
E W
EW
Rice
M J
MJ
Allen
S C
SC
Edberg
D000818:Animals; D001431:Bacteriological Techniques; D004926:Escherichia coli / Q000201:enzymology / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D005966:Glucuronidase / Q000032:analysis*; D006801:Humans
D005966:Glucuronidase