Long-range dispersal moved Francisella tularensis into Western Europe from the East

摘要: For many infections transmitting to humans from reservoirs in nature, disease dispersal patterns over space and time are largely unknown. Here, a reversed genomics approach helped us understand yielded insight into evolution biological properties of Francisella tularensis, the bacterium causing tularemia. We whole-genome sequenced 67 strains characterized by single-nucleotide polymorphism assays 138 strains, collected individuals infected 1947-2012 across Western Europe. used data for phylogenetic, population genetic geographical network analyses. All (n=205) belonged monophyletic recent ancestry not found outside Most (n=195) throughout study area were assigned star-like phylogenetic pattern indicating that colonization Europe occurred via clonal expansion. In East area, more diverse, consistent with founder spreading east west. The relationship geographic distance within F. tularensis was complex indicated multiple long-distance events. Mutation rate estimates based on year isolation null rates; outbreak hotspots only, there 0.4 mutations/genome/year. Patterns nucleotide substitution showed marked AT mutational bias suggestive drift. These results demonstrate tularemia has moved west biology long-range events mostly slow, but variable, replication rates. indicate mutation-driven evolution, resting survival phase, drift have interacted generate diversity this species.