Food borne pathogens elimination

After ingestion of any microorganism by a host animal, it can become established in the animal or eliminated. When the microorganism becomes established, it can be at high or low population levels (Fuller, 1992). Ducluzeau et al. (1970) described the barrier effect, which is a condition in the intestinal tract that protects the host from colonization by outside microorganisms. The barrier is established after birth with a small number of bacterial species, and over time, new species will be established. Some of the species involved in colonization have been well documented and are not discussed in this chapter. The barrier can be very important with respect to the administration of a DFM. The DFM must be administered daily to become established as one of the organisms in the natural barrier if it is to continuously provide the desired effects (i.e., suppression of a food-borne pathogen). 

After aflatoxin contamination, perhaps the next most important factor that has a negative effect on human health and food quality is the presence of food borne bacteria. Several routes for reduction of the risk are currently under extensive investigation. One such means of risk reduction is the utilization of ionizing radiation treatments on meat food products. Ionizing radiation has been demonstrated to be an effective method to reduce or eliminate several species of food borne human pathogens such as Salmonella, Campylobacter, Listeria, Trichinella, and Yersinia Chapter 23). If proper processing conditions are used, it is possible to produce high quality, shelf-stable, commercially sterile muscle foods. 

It appears that the animal-host-specific serotypes (e.g. 5. dublin in cattle and sheep, S. abortusovis in sheep and S, cholerasuis in pigs are not commonly associated with cases of human salmonellosis, though one rare outbreak due to S. dublin in unpasteurised milk has recently been reported by Small Sharp. This suggests that veterinary control measures, applied to eliminate clinical salmonellosis from herds and flocks, for justified medical and economic reasons, will be unlikely to reduce the incidence of food-borne outbreaks of human salmonellosis which appear to be caused primarily by opportunistic pathogens. 

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