PT  - JOURNAL ARTICLE
AU  - Tatum D. Mortimer
AU  - Douglas S. Annis
AU  - Mary B. O’Neill
AU  - Lindsey L. Bohr
AU  - Tracy M. Smith
AU  - Hendrik N. Poinar
AU  - Deane F. Mosher
AU  - Caitlin S. Pepperell
TI  - Adaptation of <em>Staphylococcus saprophyticus</em> at the host-pathogen interface
AID  - 10.1101/136556
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 136556
4099  - http://biorxiv.org/content/early/2017/05/10/136556.short
4100  - http://biorxiv.org/content/early/2017/05/10/136556.full
AB  - Human-pathogenic bacteria are found in a variety of niches, including free-living, zoonotic, and microbiome environments. Identifying bacterial adaptions that enable invasive disease is an important means of gaining insight into the molecular basis of pathogenesis and understanding pathogen emergence. Staphylococcus saprophyticus, a leading cause of urinary tract infections, can be found in the environment, food, animals, and the human microbiome. We identified a selective sweep in the gene encoding the Aas adhesin, a key virulence factor. The mutation under selection affects binding to host fibronectin, and we hypothesize that it facilitates colonization of the urinary tract, an environment where bacteria are subject to strong shearing forces. The mutation appears to have enabled emergence and expansion of a human pathogenic lineage of S. saprophyticus. These results demonstrate the power of evolutionary genomic approaches in discovering the genetic basis of virulence and emphasize the pleiotropy and adaptability of bacteria occupying diverse niches.