Potential Health Risk from Unpasteurised Cheeses?

If cheese has been made from the unpasteurised milk of a herd of cattle which has just failed its annual tuberculosis test, it is unclear as to whether the causative bacterium M. bovis would still be viable in the cheese.

31Mar 2010 --- A Food Standards Agency funded project: "Survival of Mycobacterium bovis and VTEC in UK cheeses made from raw cows´ milk" has investigated whether Escherichia coli O157 and M. bovis present a significant risk to human health in cheeses made from unpasteurised milk. The findings suggest that there could potentially be a problem. To discuss the findings of the research, Campden BRI is holding a seminar on 22nd June 2010.

Phil Voysey, event director, comments: "If cheese has been made from the unpasteurised milk of a herd of cattle which has just failed its annual tuberculosis test, it is unclear as to whether the causative bacterium M. bovis would still be viable in the cheese. There is also uncertainty as to whether another pathogenic bacterium (Verocytotoxin-producing Escherichia coli), which has been linked to cheese, is likely to survive. To investigate this, benchmark cheeses (Cheddar, Caerphilly and Camembert-type) have been produced in the laboratory and inoculated with the pathogens, and their survival determined. We will be discussing some of the findings at the seminar."

The seminar will also provide an introduction to cheesemaking and the various roles of microorganisms, and specifically look at the behaviour of the tuberculosis organism M. bovis and of E. coli O157 and other VTECs in cheeses.