Hostname: page-component-745bb68f8f-lrblm Total loading time: 0 Render date: 2025-01-27T00:32:33.871Z Has data issue: false hasContentIssue false
  • English
  • Français

Rapid and automated detection of salmonella by electrical measurements

Published online by Cambridge University Press:  19 October 2009

M. C. Easter  and
D. M. Gibson
M. C. Easter
Affiliation:
Flour Milling and Baking Research Association, Chorleywood, Herts, WD3 5SH
D. M. Gibson
Affiliation:
Ministry of Agriculture, Fisheries and Food, Torry Research Station, P.O. Box 31, 135 Abbey Road, Aberdeen AB9 8DG
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A rapid method for determining the presence of salmonella in food is described. It consists of pre-enrichment in buffered peptone water modified by the addition of dulcitol. and trimethylamine oxide, followed by selective enrichment in a selenite—cystine broth with similar modifications. Changes in the conductance of the selective enrichment broth are monitored continuously using a suitable impediometric instrument. Most of the Salmonella spp. tested gave a fast (˜100 μS/h) and large (> 600 μS) change in conductance, other enteric bacteria much less or no change. The assay is usually complete within 24 h. Samples of foodstuffs, naturally and artificially contaminated with Salmonella spp., were all correctly classified. Some strains of Citrobacter freundii produced a false positive conductance response, and they could not be selectively eliminated using antibiotics or cyanide. The conductance method is simple and easy to use, gives rapid results and involves less media and subculturing than is required for traditional methods.

Type
Research Article
Information
Journal of Hygiene , Volume 94 , Issue 3 , June 1985 , pp. 245 - 262
Copyright
Copyright © Cambridge University Press 1985

References

REFERENCES

Baynes, N. C., Comrie, J. & Prain, J. H. (1983). Detection of bacterial growth by the Malthus conductance meter. Medical Laboratory Sciences 40, 149–158.Google ScholarPubMed
D'Aoust, J. V. (1984). Salmonella detection in foods: present status and research needs for the future. Journal of Food Protection 47, 78.CrossRefGoogle ScholarPubMed
Easter, M. C, Gibson, D. M. & Ward, F. B. (1982). A conductance method for the assay and study of bacterial trimethylamine oxide reduction. Journal of Applied Bacteriology 52, 357–365.CrossRefGoogle Scholar
Easter, M. C., Gibson, D. M. & Ward, F. B. (1983). The induction and location of trimethylamine-N-oxide reductase in Alteromonas sp. NCMB 400. Journal of General Microbiology 129, 3689–3696.Google Scholar
Edwards, P. R. & Ewing, W. H. (1972). Identification of Enterobacteriaceae, 3rd ed.Minneapolis: Burgess.Google Scholar
Harvey, R. M. S. & Price, T. H. (1979). A review. Principles of salmonella isolation. Journal of Applied Bacteriology 46, 27–56.CrossRefGoogle ScholarPubMed
I.C.M.S.F. (1978). Microorganisms in Foods. Vol. I. Their Significance and Methods of Enumeration, 2nd ed., pp. 160–172. London: University of Toronto Press.Google Scholar
Kim, K. E. & Chang, G. W. (1974). Trimethylamine oxide reduction by Salmonella. Canadian Journal of Microbiology 20, 1745–1748.CrossRefGoogle ScholarPubMed
Leifson, E. (1936). New selenite enrichment media for the isolation of typhoid and paratyphoid (Salmonella) bacilli. American Journal of Hygiene 24, 423–432.Google Scholar
Petitt, S. B. (1983). Detection of ‘coliforms’ and Enterobacteriaceae. Journal of Applied Bacteriology 55, vii.Google Scholar
Porter, I. A., Reid, T. M. S., Wood, W. J., Gibson, D. M. & Hobbs, G. (1983). Conductance measurements for determining antibiotic sensitivity. In Antibiotics Asssessment of Antimicrobial Activity and Resistance (ed. Russell, A. D. & Quesnel, L. B.), pp. 49–60. London: Academic Press.Google Scholar
Richards, J. C. S., Jason, A. C., Hobbs, G., Gibson, D. M. & Christie, R. H. (1978). Electronic measurement of bacterial growth. Journal of Physics E: Scientific Instruments 11, 560–568.CrossRefGoogle ScholarPubMed
Silverman, M. P. & Munoz, E. F. (1979). Automated electrical impedance technique for rapid enumeration of fecal coliforms in effluents from sewage treatment plants. Applied and Environmental Microbiology 37, 521–526.CrossRefGoogle ScholarPubMed
Stannard, C. J. (1983). Indicator and pathogenic organisms from foods. Journal of Applied Bacteriology 55, vii.Google Scholar
Vassiliadis, P. (1983). The Rappaport-Vassiliadis (RV) enrichment medium for the isolation of salmonellas: an overview. Journal of Applied Bacteriology 54, 69–76.CrossRefGoogle ScholarPubMed
Wilson, G. S. & Miles, A. (1975). Topley and Wilson's Principles of Bacteriology, Virology and Immunity, 6th ed., pp. 944–945. London: Edward Arnold.Google Scholar
Wood, A. J. & Baird, E. A. (1943). Reduction of trimethylamine oxide by bacteria. I. The Enterobacteriaceae. Journal of the Fisheries Research Board of Canada 6, 194–201.CrossRefGoogle Scholar