Table 2. Protective capacity of the SPI1-lon, SPI1-lon-fliC and SPI1-lon-fliC-rcsA mutants after oral-oral vaccination and oral or intravenous challenge in chickens.

	day 42 of life Challenge	4 DPI			14 DPI
Vaccination		Liver	spleen	caecum	liver	spleen	caecum
SPI1-lon::Cm	oral	1/6#	2/6	5/6&	1/6	0/6	3/6
SPI1-lon::Cm -fliC		1/6	0/6	0/6	0/6	1/6	2/6
SPI1-lon::Cm-fliC-rcsB::Kan		4/6	3/6	6/6&	0/6	0/6	3/6
non-vaccinated		2/6	2/6	6/6&	4/6	4/6	6/6
SPI1-lon::Cm	intravenous	3.94±0.47*	5.20±0.24*	6/6	3/6	2.40±1.41*	2/6
SPI1-lon::Cm -fliC		2.92±1.37*	4.89±0.72*	6/6	5/6	3.29±1.07	2/6
SPI1-lon::Cm-fliC-rcsB::Kan		3.97±0.20*	5.34±0.25*	6/6	6/6	3.58±0.31*	4/6
non-vaccinated		4.71±0.39	6.68±0.42	6/6	5/5	4.16±0.38	5/5

^#number of positive chickens/number of tested.

^*t-test different from the non-vaccinated control chickens at P<0.05.

^&χ² test different from the chickens vaccinated with the SPI1-lon-fliC mutant in caecum at 4 DPI (P<0.05).