Kogut at the USDA, College Station in Texas and co-authors have published a paper in Foodborne Pathogens and Disease. It reports their work in preventing Salmonella colonisation by feeding chicks particular peptides after hatching.

The researchers explain that the BT/TAMUS 2032 (BT) cationic peptides are a group of related cationic peptides produced by a Gram-positive soil bacterium, Brevibacillus texasporus. Cationic amphiphilic peptides produced by host cells have been found to stimulate or prime the innate immune responses in mammals, but little information is available on the effects of bacterial-produced peptides on host immunity.

They say that they have previously shown that BT, provided as a feed additive for four days after hatch, significantly induced protection against extra-intestinal colonisation by Salmonella enterica serovar Enteritidis.

They also found that feeding BT significantly upregulated the functional efficiency of heterophils, the avian equivalent to mammalian neutrophils.

The objective of their present study was to further evaluate the effect of BT as a non-antibiotic, antibacterial compound and a stimulator of the innate immune response of young chickens.

BT, provided as a feed additive at three different concentrations (12, 24 or 48ppm) for four days after hatch, significantly increased protection against Salmonella enterica serovar Enteritidis caecal colonisation in a concentration-dependent manner.

The Texas group also confirmed our previous results that the functional activities of heterophils from chickens fed the BT rations were significantly upregulated. In addition, they found that the functional activities of peripheral blood monocytes were significantly increased in a concentration-dependent manner when compared with monocytes isolated from chickens fed a control diet.

According to Kogut and co-authors, this is the first report of bacterial cationic peptides providing protection against Salmonella caecal colonisation. The significance of these data is that the orally delivered cationic peptides stimulate the innate response during the first week after hatch, normally a time of immunologic inefficiency and increased susceptibility to bacterial infections.

In conclusion, the researchers speculate that BT given as a feed additive during the first week after hatch could provide increased protection against a variety of bacterial pathogens because of the non-specific nature of the innate response.

Reference

Kogut M.H., H. He, K.J. Genovese and Y.W. Jiang. 2010. Feeding the BT cationic peptides to chickens at hatch reduces cecal colonization by Salmonella enterica serovar Enteritidis and primes innate immune cell functional activity. Foodborne Pathogens and Disease. January 2010, 7(1): 23-30. doi:10.1089/fpd.2009.0346.

Further Reading

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