Inactivation of Salmonella Species and Other Food-Borne Pathogens with Salmide®, a Sodium Chlorite–Based Oxyhalogen Disinfectant

Abstract

The biocidal activity of Salmide®, a sodium chlorite–based oxyhalogen disinfectant, was tested alone or in combination with disodium ethylenediaminetetraacetate (EDTA) or trisodium phosphate (Na3PO4) against nine Salmonella spp. (choleraesuis, enteritidis, hadar, heidelberg, infantis, montevideo, indiana, typhimurium, worthington) and other selected gram-positive (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus) and gram-negative bacteria (Escherichia coli O157:H7, Pseudomonas aeruginosa). After a 15-min exposure to 10mM Salmide® in distilled deionized water at 37°C, a 2.5-to 6.6-log-cycle reduction in population was observed for all of the 16 strains tested, with the exception of L. monocytogenes ATCC 19111, which appeared to be resistant (<1-log-cycle reduction). When Salmonella hadar was simultaneously exposed to 10mM Salmide® and 5 or 10mM disodium EDTA at 37°C for 4 min, the biocidal activity of Salmide® was enhanced twofold (6-log-cycle reduction) compared to that observed with 10mM Salmide® alone. Treatment with 10mM disodium EDTA alone produced no significant inactivation <1-log-cycle reduction). Exposure of Salmonella hadar to 55mM Na3PO4 alone or in combination with 10mM Salmide® yielded a greater than 6-log-cycle reduction, whereas treatment with 10mM Salmide® alone yielded a4.1-log-cycle reduction. The presence of protein (as bovine serum albumin) in treatments containing Salmide® significantly reduced the biocidal activity. These results demonstrate that Salmide® has a rapid and concentration-dependent biocidal activity against both gram-positive and gram-negative food-borne bacterial pathogens and spoilage organisms.