Table 5. Association between mouse colonization level and gross pathology score in mice infected with single-colony isolates of KanR4 and 33292.

Inoculum*	c.f.u. (mg dry caecum)−1†	Number of mice with level	Number of mice with gross pathology score (percentage)					Mean score‡
			≤1	2	3	4	≥5
TSB	0	4	4 (100 %)					0.0
11168	>103	8	4 (50 %)	1 (13 %)		1 (13 %)	2 (25 %)	2.5
KanR4 (S)	0	5	3 (60 %)		1 (20 %)	1 (20 %)		1.8
KanR4 (S)	1–103	3	3 (100 %)					1.0
KanR4 (S)	>103	8	3 (37 %)	1 (13 %)	4 (50 %)			2.1
KanR4 (U)	0	16	10 (62 %)	4 (25 %)	2 (13 %)			1.2
33292	0	7	4 (57 %)	1 (14 %)	2 (29 %)			1.6
33292	1–103	2	1 (50 %)	1 (50 %)				1.0
33292	>103	23	6 (26 %)	8 (35 %)	4 (17 %)	1 (4 %)	4 (17 %)	2.9

^*(S), Successful genotypes SCK1 and SCK7; (U), unsuccessful genotypes SCK18 and SCK21.

^†Colonization level in the caecum at the time of necropsy.

^‡Mean gross pathology score.