Comparison of virulence of Francisella tularensis ssp. holarctica genotypes B.12 and B.FTNF002-00

BMC Veterinary Research

Table 2 Clinical and post mortem data of Fischer 344 rats (6 rats/groups) infected with Francisella tularensis ssp. holarctica

Strain	Infectious dose	Clinical sign^a	Total weight loss (%)	Day of death^b	Seroconversion	Amount of antigen (IHC)^c
B.12	10⁰ CFU	mild	0	E	+	low
			0	E	+	minimal
			2.5	E	+	none
			3.5	E	+	none
		severe	7.3	E	+	low
		severe	24	10	-	high
	10¹ CFU	mild	0	E	+	minimal
			0	E	+	low
			3	E	+	minimal
			10.6	E	+	minimal
		moderate	3.6	E	+	minimal
		severe	18.1	8	-	high
	10² CFU	mild	0	E	+	minimal
			3.7	E	+	none
			7	E	+	minimal
			17.6	E	+	minimal
		moderate	4.6	E	+	low
		moderate	13.6	E	+	minimal
B.FTNF002-00	10⁰ CFU	mild	0	E	+	none
			3.1	E	+	none
			14.4	E	+	minimal
		severe	5.6	7	-	high
			11.4	8	-	high
			35.5	12	-	high
	10¹ CFU	mild	5.7	E	+	none
		mild	11.4	E	+	none
		moderate	9	E	+	low
		severe	12.4	7	-	moderate
			16.5	E	+	low
			21.5	9	-	moderate
	10² CFU	mild	4.8	E	+	none
		mild	6.3	E	+	none
		moderate	7.7	E	+	minimal
			9.3	E	+	low
			19.3	E	+	none
		severe	12.3	4	-	high

^aThe most severe clinical sign shown during the experiment
^bDay of death after injection; E: euthanized on day 21 post infection
^cDuring the immunohistochemical examinations the amount of antigen was evaluated in the lung, liver and spleen and was based on the number of affected organs and antigen observations/field of vision at 100× magnification

ISSN: 1746-6148