Figure 2. Detailed geographic distribution and phylogeny of Francisella tularensis subsp. holarctica subclades within group B.13. A) Countries from which groups B.13 and B.FTNF002–00 have been reported. Countries of origin for isolates assigned to select subclades within group B.13 are indicated by the letters A–H. Red and purple shading indicates the known geographic distributions of groups B.13 and B.FTNF002–00, respectively, in this and previous studies (5–9). The country of Georgia, which also contains isolates from group B.13 but is not depicted in the map, is indicated by red text and a red arrow pointing toward its location. Isolates assigned to other phylogenetic groups within F. tularensis subsp. holarctica have been reported from some of these countries (5,8), but most isolates from these countries are from groups B.13 and B.FTNF002–00. B) Single nucleotide polymorphism–based phylogeny of previously (5,6,8) and newly identified subclades within the B.13 group of F. tularensis subsp. holarctica. Terminal subgroups representing sequenced strains are shown as stars, and intervening nodes representing collapsed branches are indicated by circles. The countries of origin for isolates assigned to each subclade are indicated: AUT, Austria; CE, central Europe, unknown country; CZE, Czech Republic; DEU, Germany; FIN, Finland; GEO, Georgia; HUN, Hungary; ITA, Italy; ROU, Romania; RUS, Russia; SWE, Sweden; UKR, Ukraine). For mapping purposes, letters are assigned to a previously identified subclade that contains a new isolate from Hungary now assigned to that subclade (A) and newly identified subclades (B–H). The number of isolates listed for each subclade refers only to isolates examined directly in this study (Table A1).