Salmonella niche specialization

Salmonella evolution

Evolutionary trends associated with niche specialization as modeled by whole genome analysis of egg-contaminating Salmonella enterica serovar Enteritidis
from Jean Guard, Devendra Shah, Cesar A. Morales and Doug Call writing in Salmonella: From Genome to Function

The mosaic nature of the Salmonella enterica genome facilitates its access to multiple environments. Many large scale genomic events have been described that contribute to the combinatorial complexity of the pathogenic Salmonellae. However, the impact of small scale genetic change occurring at the level of single nucleotide polymorphism (SNP) on the emergence of niche specialization is just now becoming appreciated. A recent review describes concepts behind the evolution that culminated in the remarkable ability of Salmonella enterica serovar Enteritidis to contaminate and survive in the internal content of eggs produced by otherwise healthy hens. Evidence suggests that combinations of SNPs facilitate niche specialization by Salmonella enterica. However, few typing methods incorporate unbiased strategies for their detection. Selection of appropriate biological assays for ranking SNPs and combinations of SNPs for their impact on the ability of Salmonella enterica to propagate outbreaks, pandemics and disease will be a significant challenge to improve the safety of the food supply.

Further reading: Salmonella: From Genome to Function