Addition of a surfactant to tryptic soy broth allows growth of a Lactic Acid Bacteria food antimicrobial, Escherichia coli O157:H7, and Salmonella enterica

Aims:  This study aimed to determine the survival and growth of Escherichia coli O157:H7 and Salmonella enterica subsp. enterica in a medium supporting the growth of a Lactic Acid Bacteria (LAB) food antimicrobial culture. Methods and Results:  Foodborne pathogens and LAB were cultured individually in tryptic soy broth (TSB), tryptic soy broth supplemented with one g l −1 Tween 80 ® (TSB‐T80), and de Man, Rogosa and Sharpe (MRS) broth. Growth of E. coli O157:H7 and Salmonella was similar in TSB and TSB‐T80 but was significantly less in MRS. Conversely, LAB growth was similar in MRS and TSB‐T80 but was significantly less in TSB. Conclusions:  Supplementation of TSB with Tween 80 ® allows growth of LAB to levels similar to that observed with MRS but does not inhibit the growth of E. coli O157:H7 and Salmonella . We present the formulation of a medium useful in studies useful for evaluating competitive inhibition of foodborne pathogens by LAB in vitro . Significance and Impact of the Study:  This study reports the utility of TSB‐T80 for the completion of in vitro competitive inhibition assays incorporating a Lactic Acid Bacteria food safety culture.