Insights and challenges of Salmonella infection of laying hens

Salmonella infection of laying hens and subsequent contamination of eggs continues to be a public health concern. The focus of this review is to discuss some of the current and future issues that impact Salmonella association with laying hens and egg contamination. Among these issues are the impact of shifting to alternative cage free layer hen housing and away from cage batteries. Most of the focus will be on Salmonella Enteritidis as the serotype primarily associated with laying hens and the mechanisms that ensure its successful colonization, infection and subsequent contamination of table eggs. The variability in virulence and survival characteristics among S. Enteritidis strains will also be discussed including studies on detailed characterization at the molecular level. Finally, the comprehensive assessment of the laying hen gastrointestinal tract microbiota to better understand S. Enteritidis colonization and the subsequent host response will be examined.