TABLE 2.

Relative decreases in toxin release from O-serogroup O157 strains and non-O157 strains exposed to protein synthesis inhibitors

Toxin type or toxin variant	Protein synthesis inhibitor concn	Relative % decreasea in toxin release from:		Pb
		O157 strains	Non-O157 strains
Stx1	MIC	−10.1 ± 1.6	0.9 ± 2.6	0.0009
	0.25× MIC	−24.1 ± 15.2	15.8 ± 5.4	0.03
Stx2-O157-	MIC	2.0 ± 3.5	26.1 ± 2.6	<0.0001
EDL933	0.25× MIC	−18.8 ± 6.8	12.4 ± 2.9	0.0003
Stx2-O48-94C	MIC	46.2 ± 3.7	49.3 ± 4.8	NS
	0.25× MIC	13.9 ± 8.9	4.6 ± 3.9	NS
Stx2c-O157-	MIC	73.1 ± 3.2	74.4 ± 3.0	NS
FLY16	0.25× MIC	1.7 ± 7.8	−0.1 ± 6.4	NS

^aThe relative decreases in toxin release were determined as the ratio of the difference in toxin release between strains incubated with and without protein synthesis inhibitors and the response without antimicrobial drugs. Negative decrease values correspond to increases in toxin release. Sample statistics are mean ± standard error of the mean.

^bThe relative decreases in toxin release for O157 strains and non-O157 strains were compared, and the P values for the differences are shown. NS, not significant on a 5% level of significance.