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

Dwibedi, Chinmay; Birdsell, Dawn; Lärkeryd, Adrian; Myrtennäs, Kerstin; Öhrman, Caroline; Nilsson, Elin; Karlsson, Edvin; Hochhalter, Christian; Rivera, Andrew; Maltinsky, Sara; Bayer, Brittany; Keim, Paul; Scholz, Holger C; Tomaso, Herbert; Wittwer, Matthias; Beuret, Christian; Schuerch, Nadia; Pilo, Paola; Hernández Pérez, Marta; Rodriguez-Lazaro, David; ... (2016). Long-range dispersal moved Francisella tularensis into Western Europe from the East. Microbial genomics, 2(12), e000100. Microbiology Society 10.1099/mgen.0.000100

[img]
Preview
Text
mgen000100.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (2MB) | Preview

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

Item Type:

Journal Article (Original Article)

Division/Institute:

05 Veterinary Medicine > Research Foci > Host-Pathogen Interaction
05 Veterinary Medicine > Department of Infectious Diseases and Pathobiology (DIP)
05 Veterinary Medicine > Department of Infectious Diseases and Pathobiology (DIP) > Institute of Veterinary Bacteriology

UniBE Contributor:

Pilo, Paola

Subjects:

500 Science > 570 Life sciences; biology
600 Technology > 630 Agriculture

ISSN:

2057-5858

Publisher:

Microbiology Society

Language:

English

Submitter:

Paola Pilo

Date Deposited:

06 Jun 2017 15:02

Last Modified:

11 Jun 2017 02:18

Publisher DOI:

10.1099/mgen.0.000100

PubMed ID:

28348839

Uncontrolled Keywords:

Francisella tularensis; disease transmission; epidemiology; genetic variation; human; population genetics

BORIS DOI:

10.7892/boris.99343

URI:

https://boris.unibe.ch/id/eprint/99343

Actions (login required)

Edit item Edit item
Provide Feedback