Effect of trisodium phosphate on biofilm and planktonic cells of Campylobacter jejuni, Escherichia coli O157: H7, Listeria monocytogenes and Salmonella typhimurium.

Trisodium phosphate (TSP) has been approved by the United States Department of Agriculture as a post-chill antimicrobial treatment for raw poultry. This study examines the effectiveness of TSP against planktonic (suspended) and biofilm (attached) cells of Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes and Salmonella typhimurium at room temperature (RT) and 10 degrees C. At either temperature E. coli O157:H7 was the most sensitive to TSP treatments; 10(6) cfu/ml of planktonic or 10(5) cfu/cm2 of biofilm cells were eliminated by a 30 s treatment with 1% TSP. Campylobacter jejuni was slightly less sensitive. Listeria monocytogenes was the most resistant to the effect of TSP, requiring exposure to 8% TSP for 10 min (RT) or 20 min (10 degrees C) to reduce biofilm bacteria by at least one log. Biofilm cells of S. typhimurium and Listeria monocytogenes were more resistant than planktonic cells. Salmonella typhimurium was more sensitive to treatments using TSP at 10 degrees C than at RT. In contrast, L. monocytogenes was more resistant to TSP at 10 degrees C. Trisodium phosphate appears to be an effective treatment for reducing populations of C. jejuni, E. coli O157:H7 and S. typhimurium. This product has the potential to be used for reduction of bacterial counts on other food products besides raw poultry or on food and non-food contact surfaces.