Salmonella enteritidis hila gene fusion response after incubation in spent media from either S. Enteritidis or a poultry Lactobacillus strain

Abstract

The purpose of this study was to determine if growth of a poultry probiotic lactobacilli strain can influence S. enteritidis virulence expression by measuring the response of a hilA‐lacZY transcriptional fusion, ß‐galactosidase activity was not detected when S. enteritidis was incubated in Lactobacillus‐spent medium (24 h growth, pH 4.1, 50.4 mM lactate) but was detectable in spent medium from 4 h growth cultures of Lactobacillus sp. (final OD of 0.213, pH 5.7, 12 mM lactate) when pH and lactate were adjusted to that of the 24 h‐pH 4 spent media levels. Adjusting the pH of the 24 h spent medium from 4 to 6, resulted in a measurable ß‐galactosidase activity that was significantly higher than expression in LB broth. When S. enteritidis was grown in Salmonella‐spent media (24 h growth, pH 4.2,78 mM acetate), hilA expression was increased 4‐fold over expression in the LB broth.

Keywords:

• Salmonella enteritidis
• probiotic
• poultry
• spent media
• Lactobacillus

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