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U.S. Department of Health and Human Services

Animal & Veterinary

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FDA Veterinarian Newsletter May/June 1998 Volume XIII, No III

On March 13, 1998, FDA approved the first competitive exclusion (CE) product for animals in the U.S. CE products are made up of live bacteria that can be given to animals to establish normal gut-microflora, thereby helping to reduce or prevent the colonization of undesirable bacteria, including zoonotic pathogens. By populating the gut with normal microflora, thereby excluding undesirable bacteria, CE products may help reduce carcass contamination and the incidence of foodborne illness in humans. This first approved CE product, PREEMPT™, is approved for the early establishment of intestinal microflora in baby chicks to reduce Salmonella colonization. The use of PREEMPT™ establishes bacteria that are native to the intestinal tract, creating an environment in which organisms such as Salmonella are less likely to become established.

PREEMPT™ is a defined mixture of 29 bacteria originally obtained from healthy broiler chickens. A single spray of bacterial suspension will be administered to newly hatched chicks, at a dose of approximately 0.25 milliliter per chick. The bacteria on the chick's feathers are subsequently ingested through normal grooming (preening) behavior.

Reduction of Salmonella colonization in chickens is an important step in reducing Salmonella contamination in processed poultry products. While Salmonella colonization is generally not a problem for the chickens, it is a problem for humans who may develop salmonellosis through the ingestion of improperly cooked or handled Salmonella-contaminated chicken.

While the use of CE culture products in newly hatched chicks will help to reduce Salmonella colonization in chickens, such products alone will not eliminate salmonellosis in humans. Other measures, such as Hazard Analysis and Critical Control Point (HACCP) Systems are currently being implemented at poultry processing plants to further reduce Salmonella contamination in chickens. While the use of PREEMPT™ will help reduce one type of contamination, poultry must be properly handled and cooked to be safe.

This CE culture product was originally developed and tested by a USDA/Agricultural Research Service team at College Station, Texas. This specific culture is produced as PREEMPT™ under an exclusive licensing agreement between the USDA and MS BioScience.

During clinical studies, no adverse effects were observed in the chicks following PREEMPT™ administration. In addition since PREEMPT™ is a suspension of bacteria, there are no concerns regarding chemical residues in edible tissue from treated chickens. However, since this product consists of live bacteria, using antimicrobials in feed or drinking water along with PREEMPT™ would inhibit the survival and ultimate establishment of these organisms in the gut.

Michael A. Friedman, M.D., FDA's lead deputy commissioner said "This approval marks another successful step in the concerted effort FDA, USDA, and other government agencies have made to enhance the safety of the nation's food supply. FDA is committed to facilitating the development of any promising technology that can improve food safety at every stage -- from farm to table."