Comparative Genomics of Salmonella Could Reveal Key Features of Adaptation

Worldwide, Salmonella enterica remains an important health threat. A recent study by the World Health Organization estimated that nontyphoidal S. enterica causes ∼ 230,000 deaths annually [1]. The biology of this pathogen has been studied for almost a century [2]; until recently, however, we have started to elucidate genomic features of adaptation to its hosts. Now, it is know that S. enterica has evolved to establish sympatric (generalists) and allopatric (specialists) and associations with its host. For example, S. enterica subspecies enterica, serotypes Choleraesuis, Dublin and Gallinarum have established allopatric association with porcine, bovine and avian species, respectively. In contrast, serotype Enteritidis and Typhimurium have adapted a sympatric strategy to colonize the intestinal tract of a broad number of avian and mammalian species [3]. This progress in knowledge has been accomplished with the aid of molecular microbiology.