. 2007 Mar 23;73(10):3239–3244. doi: 10.1128/AEM.02764-06

TABLE 1.

Radiation D₁₀ values for planktonic and biofilm-associated cells of E. coli O157:H7 isolates C9490, 43894, and 35150

Isolate^a	Isolate culture age^b												Maturity P values^c
	24 h				48 h				72 h
	CFU/ml (±SD)	D₁₀ (kGy)	r² value	P value significance	CFU/ml (±SD)	D₁₀ (kGy)	r² value	P value significance	CFU/ml (±SD)	D₁₀ (kGy)	r² value	P value significance
C9490-P	9.18 ± 0.08	0.653	0.96	A	9.28 ± 0.08	0.494	0.95	A	9.26 ± 0.04	0.478	0.98	A	*
C9490-B	7.04 ± 0.28	0.479	0.90	B	7.61 ± 0.40	0.442	0.80	ACD	7.00 ± 0.47	0.490	0.84	A	NSD
43894-P	9.08 ± 0.11	0.479	0.97	B	8.82 ± 0.65	0.454	0.96	AC	8.98 ± 0.17	0.465	0.93	A	NSD
43894-B	8.03 ± 0.90	0.385	0.94	C	7.62 ± 0.31	0.381	0.85	D	7.74 ± 0.30	0.382	0.94	B	NSD
35150-P	9.08 ± 0.05	0.396	0.97	C	9.29 ± 0.06	0.454	0.99	BC	9.37 ± 0.05	0.469	0.99	A	*
35150-B	6.59 ± 0.24	0.526	0.74	B	6.75 ± 0.31	0.464	0.92	AB	6.88 ± 0.17	0.503	0.90	A	NSD

Isolates were evaluated as planktonic cells (suffix “P”) or as biofilm-associated cells (suffix “B”).

Observed log CFU/ml populations are shown for control (0.0 kGy) samples, mean of 9 samples, plus or minus standard deviations (SD). r² values of the linear regression model were used to calculate D₁₀ values. D₁₀ values for a given time of cultivation shown with the same letter (A, B, C, and D) are not significantly (P < 0.05) different (by analysis of covariance).

D₁₀ values for a given isolate/cultivation method are either significantly different (*, P < 0.05) or not significantly different (NSD) across the three times of cultivation (by analysis of covariance).