Yersinia pestis pFra Shows Biovar-Specific Differences and Recent Common Ancestry with a Salmonella enterica Serovar Typhi Plasmid
Prentice MB., James KD., Parkhill J., Baker SG., Stevens K., Simmonds MN., Mungall KL., Churcher C., Oyston PCF., Titball RW., Wren BW., Wain J., Pickard D., Hien TT., Farrar JJ., Dougan G.
ABSTRACT Population genetic studies suggest that Yersinia pestis , the cause of plague, is a clonal pathogen that has recently emerged from Yersinia pseudotuberculosis . Plasmid acquisition is likely to have been a key element in this evolutionary leap from an enteric to a flea-transmitted systemic pathogen. However, the origin of Y. pestis -specific plasmids remains obscure. We demonstrate specific plasmid rearrangements in different Y. pestis strains which distinguish Y. pestis bv. Orientalis strains from other biovars. We also present evidence for plasmid-associated DNA exchange between Y. pestis and the exclusively human pathogen Salmonella enterica serovar Typhi.