TABLE 2.

Mean net growth rates and lag durations of E. coli strains with respect to their level of susceptibility and culture conditions^a

Strain susceptibility (n)b	Mean net growth rate (r)		Lag duration (h)
	MHB	AFC	MHB	AFC
Intermediate-resistant (8)	1.47 (1.34, 1.62)	0.97 (0.82, 1.12)*	1.31 (1.11, 1.51)	1.15 (1.06, 1.24)*
Resistant (8)	1.41 (1.29, 1.55)	1.11 (1.07, 1.22)*	1.31 (1.21, 1.41)	1.22 (1.08, 1.37)*
All (16)	1.44 (1.37, 1.53)	1.04 (0.95, 1.13)*	1.31 (1.22, 1.40)	1.19 (1.11, 1.26)*

^aValues in parentheses represent 95% confidence intervals. MHB, optimal growth conditions; AFC, intestinal growth conditions. Statistical comparison was performed using analysis of variance with a significance level at 0.05. For each parameter, asterisks indicate significant differences according to culture medium. No differences were observed between intermediate-resistant and resistant strains.

^bn, number of strains.