Inhibition of Salmonella enterica Cells in Deli-Type Salad by Enterocin AS-48 in Combination with Other Antimicrobials

The cyclic antibacterial peptide enterocin AS-48 acted synergistically with p-hydroxybenzoic acid methyl ester (PHBME) and with 2-nitropropanol against Salmonella enterica serovar Enteritidis CECT 4300 in Russian salad. In challenge tests on a cocktail of Salmonella strains (S. enterica ssp. enterica serotype Typhi CECT 409, S. enterica ssp. enterica serovar Choleraesuis CECT 915, S. enterica ssp. enterica serovar Enteritidis CECT 4300, S. enterica ssp. arizonae serovar Arizonae CECT 4395, and S. enterica ssp. salamae CECT 4000) in salad at 10 degrees C, the combinations of PHBME and AS-48 (80 mu g/g) or 2-nitropropanol and AS-48 (40 mu g/g) reduced the concentrations of viable Salmonella from 4.27 to 4.75 log CFU/g down to the limit of detection for 7 days. Salmonella populations did not increase in control samples (without any antimicrobials or in the presence of AS-48 alone) probably due to the low pH of this type of salad and low temperature of incubation, but retained over 85% viability after 1 week. This work opens new possibilities to expand the spectrum of inhibition of enterocin AS-48 against Salmonella enterica.