Identification and Quantification of Fecal Coliforms using Violet Red Bile Agar at Elevated Temperature

Abstract

A procedure was developed for identification and quantification of fecal coliforms by colony size obtained in Violet Red Bile agar incubated at 44.5 ± 0.5 C for 24 h in an air incubator. Five strains of Escherichia coli, 5 strains of Enterobacter aerogenes, 37 coliform isolates from sewage, and 76 coliform isolates from water were tested by this procedure. The practical usefulness of this procedure was studied by comparative quantification of 11 water samples using this procedure, the Millipore method, and MPN method. Statistical analysis showed that this procedure is as reliable as the other procedures for enumeration of fecal coliforms. The advantages of this method over the commonly used methods of enumeration of fecal coliforms are ease of operation, simplicity, and speed.