The Salmonella Enteritidis Lipopolysaccharide Biosynthesis Gene rfbH is Required for Survival in Egg Albumen

Salmonella Enteritidis is still a major cause of human food borne infections and can be associated with the consumption of meat and chicken eggs. It is the world's most common cause of salmonellosis in part because it has the ability to colonize the oviduct and contaminate eggs. It was shown that when stored at room temperature, S. Enteritidis bacteria can multiply extensively in contaminated eggs. Using the in vivo expression technology, it was shown that the rfbH gene, involved in lipopolysaccharide O-antigen synthesis, is transcriptionally induced during growth in whole eggs at room temperature. A S. Enteritidis Delta rfbH strain was unable to multiply in eggs at room temperature and did not survive in egg white at 42 degrees C. The attenuation was most likely caused by an increased susceptibility of the Delta rfbH mutant to yet undefined antibacterial components of the egg albumen.