Table 2.

Virulence of the lrp mutants in the mouse

Strain	Description	LD50 (cfu/mouse)	Fold relative to YJ016
YJ016	Wild type	4.84 × 105	1
NY303	Spontaneous attenuated mutant	1.99 × 108	411
YH01	YJ016Δlrp	1.45 × 108	300
YH03	YH01(plrp)	3.72 × 105	0.77
YH06	YJ016 lrp*	5.46 × 106	11
NY303–2	YJ016 ΔvvhΔvpl	9.49 × 105	2
CH08	NY303–2 -lrp*	7.00 × 107	145
CS9133	Wild-type strain (biotype 1)	3.79 × 105	0.78
CH09	CS9133Δlrp	4.43 × 107	92
CECT4999	Wild-type strain (biotype 2)	2.50 × 105	0.52
CH10	CECT4999Δlrp	6.32 × 107	131

The bacteria were injected subcutaneously into the mouse, and the mortality was recorded within 72 h