Quantitative determination of Escherichia coli from faecal coliforms in seawater

Abstract

A simple rapid method was developed for counting Escherichia coli in sea water using a membrane filter procedure. Following filtration the membrane filter was incubated on mFC agar medium for 24 +/- 2 h at 44.5 +/- 0.2 degrees C for determination of faecal coliforms. An in situ test for the determination of E. coli was carried out by transferring the membrane filter to nutrient agar containing 4,methyl-umbiliferyl-B-D, glucoronide, followed by incubation for 3 h at 35 degrees C. The E. coli colonies were detected by fluorescence under long wavelength UV light. Extensive biochemical confirmation tests on the isolates showed that all the fluorescence colonies which were either lactose positive or negative were E. coli.