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D. R. KORBER, Dept. of Applied Microbiology & Food Science, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada

Meat carcasses are typically exposed to bacterial contamination at some point following the slaughter of the animal, with most enteric pathogens originating from the slaughtered animal itself. These meatborne organisms subsequently attach to, and colonize, other exposed surfaces throughout the processing plant, and in that way may spread to often unexpected locations throughout the facility. Reducing the initial load of bacteria from meat carcasses is of obvious importance for minimizing the effects of downstream contamination. Procedures for reducing the load of attached microorganisms from meat products include spraying carcasses with various antimicrobial solutions, and performing water cleansing or steam pasteurizing. Unfortunately, these approaches have not proven sufficient for the removal or eradication of all bacteria. One reason for this is that once bacteria have attached to a surface, they undergo physiologic changes which render them more resistant to the action of antimicrobial agents. Furthermore, pathogens commonly live in association with many non-pathogenic bacteria, further complicating their attenuation. Until recently, the majority of antimicrobial agents and strategies for industrial application were evaluated using lab-cultured isolates grown in batch culture, and hence were not entirely appropriate as models for the meat microenvironment or microflora. It is consequently of value to perform antimicrobial efficacy studies using model systems which may readily be compared with results obtained on actual meat surfaces. In this paper, approaches based on confocal laser microscopy and fluorescent molecular probes are compared with traditional plating methods both on meat and model surfaces. Novel and traditional methods for attenuation and control of food pathogens are also evaluated, as are limitations of such approaches.