Effects of Trisodium Phosphate on Populations of Salmonella Typhimurium and Salmonella Enteritidis in Vitro

Abstract

This study determined the bactericidal activity of different concentrations of trisodium phosphate (TSP) against Salmonella typhimurium and Salmonella enteritidis in vitro. One milliliter of each TSP solution (0.5, 1, 1.5 and 2% w/v) was mixed with 1 mL of each bacterial culture and left to stand at room temperature (18 +/- 1C) for 0, 15, 30, 45, 60 or 90 min before enumeration of the surviving pathogens. The effects of 1.5 and 2% TSP were apparent on both bacterial species from 0 min and bacterial counts reached undetectable (< 1.0 x 10(1) cfu/mL) levels immediately. The 1% TSP solution effected close to 4.20-5.72 log reduction after 15 min. However, the reduction effect of 0.5% TSP was a function of treatment time, and some culturable bacteria remained even after 90 min of treatment. These results suggest that the bactericidal effect of TSP solution on these pathogens depends on its concentration and on the duration of treatment.