High-resolution melting PCR assay as a powerful tool for the epidemiological surveillance of tularemia in Western Europe.

ABSTRACT

In Europe, tularemia is caused by Francisella tularensis subsp. holarctica and is a sporadic disease affecting mainly wildlife animals and humans. Classification of this species relies on canonical single nucleotide polymorphisms (canSNPs). Four main clades have been described for F. tularensis subsp. holarctica B.4, B.6, B.12 and B.16. Phylogeographic studies have shown that clade B.6 is predominant in Western Europe and B.12 in Eastern and Central Europe. Based on this global phylogeny, we aimed to design a molecular typing assay for all genetic subclades of subclade B.11, which is the predominant subclade in clade B.6. We designed high-resolution melting (HRM) primers for the screening of 109 canSNPs divided in seven orders of discrimination for the molecular epidemiology analysis and tracking of Francisella tularensis subsp. holarctica in Western Europe.