Some modification to the media for rapid automated detection of salmonellas by conductance measurement

Abstract

A selenite medium for the automated detection of salmonellas by conductance measurements has been modified to eliminate the negative results given by some dulcitol-negative strains. The dulcitol is replaced with mannitol and pre-enrichment is best done in buffered peptone water containing mannitol and dimethylsulphoxide. It is suggested that both versions of the selenite medium be used initially.

Electrical methods

“…Gibson (1987b) substituted mannitol for dulcitol with excellent results. Gibson (1987b) substituted mannitol for dulcitol with excellent results.…”

Series quartz crystal sensor for remote bacteria population monitoring in raw milk via the Internet

“…It is based on the measurement of changes in electrical impedance of a medium or a reaction solution resulting from the growth of bacteria. The majority of previous studies on the determination of bacterial counts have focused on the modification of the medium, aiming at the optimization of the electrical signals (Easter and Gibson, 1985;Gibson, 1987;Ogden and Cann, 1987;Pettipher and Watts, 1989) or supporting the selective growth of target bacteria against other bacteria (Ogden, 1988). The impedance method was approved as an official method for the detection of Salmonella in foods by the Association of Analytical Communities (AOAC) (Yang et al, 2004;Salmonella in foods, 1996).…”

Food‐borne Pathogenic Bacteria

“…The initial impedance detection medium for Salmonella was selenite-cystine/trimethylamine oxide/dulcitol (Easter and Gibson, 1985). Due to negative results for some Salmonella strains, dulcitol in the medium was replaced by mannitol (Gibson, 1987;Ogden and Cann, 1987). Greater impedance changes were obtained with mannitol or deoxyribose in place of dulcitol (Pettipher and Watts, 1989a).…”