Table 2.

HEp-2 invasiveness of the 36 AIEC isolated from patients with CD (CD1-4) and from non-IBD controls (Control 1-4)

Sample origin	N of invasive strains	a(%) Average invasion level
CD1	14	0.50 ± 0.15
CD2	9	0.40 ± 0.11
CD3	8	0.88 ± 0.27
CD4	0	–
Control 1	4	0.67 ± 0.10
Control 2	1	0.52 ± 0.15
Control 3	0	–
Control 4	0	–
Reference strains	E. coli LF82	0.95 ± 0.30
	E. coli DH5α	0.007 ± 0.005

^aValues represent the mean percentages ± standard deviations of the means of internalised bacteria and are expressed as the ratio of intracellular CFU/number of bacteria used to infect cell monolayers X 100. Data represent mean and standard errors of three independent experiments, in duplicate.

--, not determined.