Abstracto

New Culture Media for Fast, Sensitive and User-Friendly Detection of E.Coli and/or Coliform Bacteria

Etienne Schaeffer, Jacques Haiech and Jean-Luc Galzi

Objective: Bacterial contamination of drinking water is a public health concern ruled by national standards and by the world health organization guidelines. Efforts have thus been constantly devoted to improve detection of markers of contamination as early as possible, each time contamination. In this work, we optimize detection of coliform bacteria in general, and of E. coli in particular, by modifying specific growth media.

Methods and results: By reinvestigating key parameters such as selectivity, growth kinetics, signal intensity, number of steps in sample manipulation and signal monitoring, we succeeded in i) improving the rate of bacterial contamination detection (medium SMIL), ii) finely tune the ratio of contamination revelation over bacterial growth (medium SMIM), or iii) designing a user-friendly and cost-effective signal detection system (Chromo-SMIM medium).

Conclusions: SMIM and SMIM-derived media present a better β-galactosidase (present in all coliforms) activity detection compared to classical methods. This new method thus is a useful improvement of standard techniques used worldwide in water-control analytical laboratories.