title: Early emergence of Yersinia pestis as a severe respiratory pathogen.
abstract: Yersinia pestis causes the fatal respiratory disease pneumonic plague. Y. pestis recently evolved from the gastrointestinal pathogen Y. pseudotuberculosis; however, it is not known at what point Y. pestis gained the ability to induce a fulminant pneumonia. Here we show that the acquisition of a single gene encoding the protease Pla was sufficient for the most ancestral, deeply rooted strains of Y. pestis to cause pneumonic plague, indicating that Y. pestis was primed to infect the lungs at a very early stage in its evolution. As Y. pestis further evolved, modern strains acquired a single amino-acid modification within Pla that optimizes protease activity. While this modification is unnecessary to cause pneumonic plague, the substitution is instead needed to efficiently induce the invasive infection associated with bubonic plague. These findings indicate that Y. pestis was capable of causing pneumonic plague before it evolved to optimally cause invasive infections in mammals.
authors.affiliation: Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Zimbler
authors.affiliation: Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Jay A
authors.initials: JA
authors.lastname: Schroeder
authors.affiliation: Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Justin L
authors.initials: JL
authors.lastname: Eddy
authors.affiliation: Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Wyndham W
authors.initials: WW
authors.lastname: Lathem
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D010930:Plague / Q000382:microbiology*; D015010:Yersinia pestis / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins