Detection of Escherichia coli in potable water using direct impedance technology |
| |
Authors: | KO Colquhoun S Timms CR Fricker |
| |
Institution: | Thames Water Utilities Ltd, Development Microbiology, Spencer House Laboratories, Reading, UK |
| |
Abstract: | Direct impedance measurement utilizing a medium previously described as being specific for Escherichia coli and which contains trimethylamine N -oxide (TMAO) and glucuronic acid was used to detect E. coli in water samples. The system was compared with the Colilert® presence/absence test and the United Kingdom standard membrane nitration technique using membrane lauryl sulphate broth. The impedance method correlated well with both the traditional membrane method (93%) and the Colilert® method (93.95%) for a number of different water types. No interference from Citrobacter spp. (as reported in previous studies) was detected in this study although some Salmonella spp. did give false-positive results. The data presented here suggest that the use of direct impedance may offer an alternative to conventional methods for the detection of E. coli in water. |
| |
Keywords: | |
|
|