Diversity of Francisella tularensis subsp. holarctica lineages, China.

Yanhua Wang,Xiaona Shen,Dawn Birdsell,Hang Li,Dongzheng Yu,Zhikai Zhang,Yao Peng,Hong Cai,Rong Hai,Lianxu Xia,David M Wagner,Paul Keim,Ying Liang

doi:10.3201/eid2007.130931

Abstract

We analyzed 10 isolates of Francisella tularensis subspecies holarctica from China and assigned them to known clades by using canonical single-nucleotide polymorphisms. We found 4 diverse subtypes, including 3 from the most basal lineage, biovar japonica. This result indicates unprecedented levels of diversity from a single region and suggests new models for emergence.

Highlights

We analyzed 10 isolates of Francisella tularensis subspecies holarctica from China and assigned them to known clades by using canonical single-nucleotide polymorphisms
The wide geographic distribution and low diversity of F. tularensis subsp. holarctica isolates have been used to argue that this clade is recently emerged and highly fit [3], but the geographic origin of its emergence has not been determined
We assigned these isolates into previously defined [6,7] phylogenetic clades and conducted a phylogeographic analysis by using a panel of 12 canonical SNP (canSNP) specific for F. tularensis subspecies or clades within F. tularensis subsp. holarctica (Table 2); these canSNPs were obtained from previous reports [6,7]

Summary

Introduction

We analyzed 10 isolates of Francisella tularensis subspecies holarctica from China and assigned them to known clades by using canonical single-nucleotide polymorphisms. The wide geographic distribution and low diversity of F. tularensis subsp. Holarctica isolates have been used to argue that this clade is recently emerged and highly fit [3], but the geographic origin of its emergence has not been determined. The derived clade (B.2/3) has been described only from 2 isolates from California, USA [7].

Results

Conclusion