Identification of Salmonella Enteritidis outer membrane proteins expressed during attachment to human intestinal epithelial cells

Aims: To express and identify the Salmonella enterica ser. Enteritidis outer membrane proteins that are involved in the attachment to human intestinal epithelial cells. Methods and Results: Salmonella Enteritidis attachment proteins were expressed by infection of human intestinal epithelial cells (int-407) with Salm. Enteritidis strain SE28, followed by pulse labelling with [S-35]-methionine. Outer membrane proteins were separated by TritonX-114 phase partitioning, and were detected by Salm. Enteritidis-specific polyclonal antibody. Outer membrane proteins of molecular weights 82.3, 75.6, 49.3, 35.5 and 19.3 kDa were newly synthesized. Expression of 31.2 and 16 kDa proteins was up-regulated, whereas the expression of 40.7 kDa protein was down-regulated. Polyclonal antibodies against the 82.3 and 75.6 kDa proteins significantly (P<0.05) reduced the binding of Salm. Enteritidis to int-407 cells in vitro. Conclusions: Outer membrane proteins 82.3 and 75.6 kDa are potentially involved in the attachment of Salm. Enteritidis to the intestinal mucosa. Significance and Impact of the Study: Outer membrane proteins 82.3 and 75.6 kDa identified in this study could be used as potential vaccines to block or reduce Salm. Enteritidis colonization in chickens.