Volume 82, Issue 5
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



Two subspecies of are recognized: subsp. (type A) and subsp. (type B). Type A has been subdivided further into A1a, A1b, and A2, which differ geographically and clinically. The aim of this work was to determine whether or not differences among subspecies and clades translate into distinct ecological niches. We used 223 isolates from humans and wildlife representing all six genotypes (type A, B, A1, A2, A1a, or A1b). Ecological-niche models were built independently for each genotype, using the genetic algorithm for rule-set prediction. The resulting models were compared using a non-parametric multivariate analysis-of-variance method. A1 and A2 are ecologically distinct, supporting the previously observed geographic division, whereas ecological niches for types A and B overlapped notably but A1a and A1b displayed no appreciable differences in their ecological niches.


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  1. Sjöstedt A, Brenner DJ, , 2005. Family XVII. FRANCISELLACEAE, genus I. Francisella. , ed. Bergey's Manual of Systematic Bacteriology. New York: Springer-Verlag. [Google Scholar]
  2. Dennis DT, Inglesby TV, Henderson DA, Barlett JG, Ascher MS, Eitzen E, Fine AD, Friedlander AM, Hauer J, Layton M, Lillibridge SR, McDade JE, Osterholm MT, O'Toole T, Parker G, Perl TM, Russell PK, Tonat K, , 2001. Tularemia as a biological weapon—medical and public health management. JAMA 285: 27632773.[Crossref] [Google Scholar]
  3. Ellis J, Oyston PC, Green M, Titball RW, , 2002. Tularemia. Clin Microbiol Rev 15: 631646.[Crossref] [Google Scholar]
  4. Staples JE, Kubota KA, Chalcraft LG, Mead PS, Petersen JM, , 2006. Epidemiologic and molecular analysis of human tularemia, United States, 1964–2004. Emerg Infect Dis 12: 11131118.[Crossref] [Google Scholar]
  5. Farlow J, Wagner DM, Dukerich M, Stanley M, Chu M, Kubota K, Petersen J, Keim P, , 2005. Francisella tularensis in the United States. Emerg Infect Dis 11: 18351841.[Crossref] [Google Scholar]
  6. Johansson A, Farlow J, Larson P, Dukerich M, Chambers E, Bystrom M, Fox J, Chu M, Forsman M, Sjöstedt A, Keim P, , 2004. Worldwide genetic relationships among Francisella tularensis isolates determined by multiple-locus variable-number tandem repeat analysis. J Bacteriol 186: 58085818.[Crossref] [Google Scholar]
  7. Kugeler KJ, Mead PS, Janusz AM, Staples JE, Kubota KA, Chalcraft LG, Petersen JM, , 2009. Molecular epidemiology of Francisella tularensis in the United States. Clin Infect Dis 48: 863870.[Crossref] [Google Scholar]
  8. Pandya GA, Holmes MH, Petersen JM, Pradhan S, Karamycheva SA, Wolcott MJ, Molins C, Jones M, Schriefer ME, Fleischmann RD, Peterson SN, , 2009. Whole genome single nucleotide polymorphism based phylogeny of Francisella tularensis and its application to the development of a strain typing assay. BMC Microbiol 9: 213.[Crossref] [Google Scholar]
  9. Jellison WL, , 1974. Tularemia in North America, 1930–1974. Missoula, MT: University of Montana. [Google Scholar]
  10. Nakazawa Y, Williams R, Peterson AT, Mead P, Staples E, Gage KL, , 2007. Climate change effects on plague and tularemia in the United States. Vector Borne Zoonotic Dis 7: 529540.[Crossref] [Google Scholar]
  11. New M, Hulme M, Jones PD, , 1999. Representing twentieth century space-time climate variability. Part 1: development of a 1961–90 mean monthly terrestrial climatology. J Clim 12: 829856.[Crossref] [Google Scholar]
  12. USGS, 2001. Hydro1K Elevation Derivative Database. Washington, DC: U.S. Geological Survey. [Google Scholar]
  13. Stockwell D, , 1999. The GARP modeling system: problems and solutions to automated spatial prediction. Int J Geogr Inf Sci 13: 143158.[Crossref] [Google Scholar]
  14. Stockwell DRB, Noble IR, , 1992. Introduction of sets of rules from animal distribution data: a robust and informative method of data analysis. Math Comput Simul 33: 385390.[Crossref] [Google Scholar]
  15. Anderson RP, Lew D, Peterson AT, , 2003. Evaluating predictive models of species' distributions: criteria for selecting optimal models. Ecol Modell 162: 211232.[Crossref] [Google Scholar]
  16. Anderson MJ, , 2001. A new method for non-parametric multivariate analysis of variance. Austr Ecol 26: 3246. [Google Scholar]
  17. Petersen JM, Carlson JK, Dietrich G, Eisen RJ, Coombs J, Janusz AM, Summers J, Beard CB, Mead PS, , 2008. Multiple Francisella tularensis subspecies and clades, tularemia outbreak, Utah. Emerg Infect Dis 14: 19281930.[Crossref] [Google Scholar]
  18. Vogler AJ, Birdsell D, Price LB, Bowers JR, Beckstrom-Stenberg SM, Auerbach RK, Beckstrom-Stenberg JS, Johansson A, Clare A, Buchhagen JL, Petersen JM, Pearson T, Vaissaire J, Dempsey MP, Foxall P, Engelthaler DM, Wagner DM, Keim P, , 2009. Phylogeography of Francisella tularensis: global expansion of a highly fit clone. J Bacteriol 191: 24742484.[Crossref] [Google Scholar]
  19. Peterson AT, , 2008. Biogeography of diseases: a framework for analysis. Naturwissenschaften 95: 483491.[Crossref] [Google Scholar]
  20. Soberón J, Peterson AT, , 2005. Interpretation of models of fundamental ecological niches and species' distributional areas. Biodiversity Informatics 2: 110.[Crossref] [Google Scholar]
  21. Warren DL, Glor RE, Turelli MN, , 2008. Environmental niche equivalency versus conservatism: quantitative approaches to niche evolution. Evolution 62: 28682883.[Crossref] [Google Scholar]

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  • Received : 23 Jun 2009
  • Accepted : 06 Dec 2009
  • Published online : 05 May 2010

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