Peptide transporter YjiY influences the expression of the virulence gene mgtC to regulate biofilm formation in Salmonella

Abstract

Biofilm is one of the coping strategies of Salmonella against antimicrobial environmental stresses including nutrient starvation. However, channeling of the cue of starvation towards biofilm formation is not understood well. Our study shows that a carbon starvation gene, yjiY, coding for a peptide transporter, influences the expression of a virulence associated gene, mgtC, in Salmonella, to regulate biofilm formation. We demonstrate here that the mutant strain, ΔyjiY, is unable to form biofilm due to the increased expression of mgtC. The upregulation of mgtC in ΔyjiY strain correlates with the downregulation of biofilm master regulator gene csgD and reduced levels of ATP. Our work further indicates that yjiY coded peptide transporter may regulate the expression of mgtC by transporting proline peptides.