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An investigation of the thermal death kinetics of Mycobacterium paratuberculosis during pasteurisation

Published online by Cambridge University Press:  27 February 2018

M.T. Rowe
Affiliation:
, Department of Food Science (Food Microbiology), The Queen's University of Belfast, Newforge Lane, Belfast BT9 5PX
I.R. Grant
Affiliation:
, Department of Food Science (Food Microbiology), The Queen's University of Belfast, Newforge Lane, Belfast BT9 5PX
H.J. Ball
Affiliation:
, Veterinary Science Division, Stoney Road, Belfast BT4 3SD, Northern Ireland, U.K.
C. Pope
Affiliation:
, Department of Food Science (Food Microbiology), The Queen's University of Belfast, Newforge Lane, Belfast BT9 5PX
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Abstract

Mycobacterium paratuberculosis is the known cause of Johne's disease in cattle and has been implicated as a cause of Crohn's disease in humans. Concern has been expressed that the organism, which is excreted in milk and faeces of infected cattle, may be transmitted via pasteurised milk. This is largely from work that has shown an unacceptable risk of survival of the organism when it is present in raw milk at numbers exceeding 102 cfu/ml. Three possible reasons for this apparent heat resistance were investigated viz. use of a milk heating menstruum, presence of a heat resistant sub–population, and the tendency of the organism to form clumps. Heat resistance studies using a combined acid–fast/viability stain, and a comparison of the relative heat sensitivities of clumped and de-clumped M. paratuberculosis cells provided circumstantial evidence that it is the organism's tendency to form clumps which confers the apparent heat resistance. This work casts doubt on the efficacy of current commercial pasteurisation heat treatments (72°C/15s) for the inactivation of M. paratuberculosis. This would be of concern if a link between M. paratuberculosis and Crohn's disease is eventually established.

Type
Offered papers
Copyright
Copyright © British Society of Animal Science 2000

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References

References Grant, I.R., Ball, H.J. and Rowe, M.T. 1997. A novel staining technique for assessing clumping and viability of Mycobacterium paratuberculosis cells during pasteurization. In Proceedings of the fifth international colloquium on paratuberculosis, (ed Chiodini, R.J., Hines II, M.E. and Collins, M.T.) pp. 374376. International Association for Paratuberculosis, Rehoboth, Massachusetts.Google Scholar
Grant, I.R., Ball, H.J. and Rowe, M.T. 1998. Effect of high-temperature, short-time (HTST) pasteurization on milk containing low numbers of Mycobacterium paratuberculosis . Letters in Applied Microbiology 26: 166170.CrossRefGoogle ScholarPubMed
Grant, I.R., Ball, H.J., Neill, S.D. and Rowe, M.T. 1995. Investigation of the thermal death of Mycobacterium paratuberculosis during pasteurisation. In Heat treatments and alternative methods, pp. 452457. International Dairy Federation, Brussels.Google Scholar
Jou, N-T., Yoshimori, R.B., Mason, G.R., Louie, J.S. and M.R., Liebling. 1997. Single-tube, nested, reverse transcriptase PCR for detection of viable Mycobacterium tuberculosis . Journal of Clinical Microbiology 35: 11611165.CrossRefGoogle ScholarPubMed
Kubica, G.P. 1984. Clinical microbiology. In The mycobacteria: a sourcebook, Part A. (ed Kubica, G.P., and Wayne, L.G.), pp. 133175. Marcel Dekker, Inc., New York.Google Scholar
Millar, D., Ford, J., Sanderson, J., Withey, S., Tizard, M., Doran, T. and Hermon-Taylor, J. 1996. IS900 PCR to detect Mycobacterium paratuberculosis in retail supplies of whole pasteurised cows’ milk in England and Wales. Applied and Environmental Microbiology 62: 34463452.CrossRefGoogle ScholarPubMed
Snyder, I.S., Johnson, W. and Zottola, E.A. 1978. Significant pathogens in dairy products. In Standard methods for the examination of dairy products, (ed Marth, E.H.) pp. 1132. American Public Health Association, Washington.Google Scholar
Streeter, R.N., Hoffsis, G.F., Bech-Nielsen, S., Shulaw, W.P. and Rings, M. 1995. Isolation of Mycobacterium paratuberculosis from colostrum and milk of subclinically infected cows. American Journal of Veterinary Research 56: 13221324.CrossRefGoogle ScholarPubMed
Stumbo, C.R. 1973. Death of bacteria subjected to moist heat. In Thermobacteriology in food processing, pp. 7092. Academic Press, New York.CrossRefGoogle Scholar
Sweeney, R.W., Whitlock, R.H. and Rosenberger, A.E. 1992. Mycobacterium paratuberculosis cultured from milk and supramammary lymph nodes of infected asymptomatic cows. Journal of Clinical Microbiology 30: 166171.CrossRefGoogle ScholarPubMed
Taylor, T.K., Wilks, C.R. and McQueen, D.S. 1981. Isolation of Mycobacterium paratuberculosis from the milk of a cow with Johne's disease. Veterinary Record 109: 532533.Google ScholarPubMed