As Guilherme Augusto Marietto Gonçalves and colleagues at Brazil's São Paulo State University explain in their paper in Poultry Science, Salmonella food poisoning is a public health problem.

Feed withdrawal from broiler chickens before slaughter can favour the multiplication of Salmonella in the caecum and crop of contaminated animals and subsequently lead to contamination of carcasses in the processing plant.

In their latest study, a cocktail of lytic bacteriophages isolated from sewage water was orally administered to 45-day-old broiler chickens one hour after they received an oral dose of 10⁷ colony-forming units (cfu) per ml of Salmonella enterica subspecies enterica serotype Enteritidis.

Immediately after phage administration and 30 minutes, one, three, six and 12 hours thereafter, groups of chicken were killed. Caeca and crops were analyzed for the presence of Salmonella.

Three hours post-treatment, there were 10³cfu per gramme and 10¹cfu per gramme of caecal and crop suspension, respectively.

Six hours after treatment, the number of Salmonella was 10³cfu per gramme in the caecal suspension but below the detection limit in the crops.

The São Paulo-based group report their results suggest that bacteriophage therapy may be able to reduce the contamination of chicken carcasses by reducing the pre-slaughter load of Salmonella in the birds.

Reference

Gonçalves G.A.M., T.C. Donato, A.A.S. Baptista, I.M. de Oliveira Corrêa, K.C.O.D. Garcia and R.L.A. Filho. 2014. Bacteriophage-induced reduction in Salmonella Enteritidis counts in the crop of broiler chickens undergoing preslaughter feed withdrawal. Poultry Science. 93(1): 216-220. doi: 10.3382/ps.2013-03360

February 2014