Table 2.

Characteristics of Francisella subspecies traditionally used to study virulence.

	F. novicida	F. tularensis subsp tularensis	F. tularensis subsp holarctica	References
Reference strains	U112	SCHU S4	LVS
Genome size	1,910,031 bp	1,892,819 bp	1,895,998 bp	[33]
Protein coding genes	1731	1145	1380	[33]
Sequence identity to SCHU S4	98.1%	/	99.2%	[34]
FPI	1 copy	2 copies	2 copies	[35]
Type VI secretion system effectors	OpiA, OpiB1–3, pdpD, pdpC	Splitted OpiA in 2 ORF, small OpiB*, pdpD, pdpC	Splitted OpiA in 2 ORF, small OpiB**, pdpC	[35–37]

*Ankyrin repeat region is absent.

**Ankyrin repeats region absent and deletion in the C-ter region.