TABLE 1.

Comparison of Stx detection in supernatants of 37 E. coli strains^a using the Vero cell cytotoxicity assay, enzyme immunoassay, and latex agglutination assay

stx geno- typeb	No. of strains	Disease associationc			No. of strains with indicated Stx detection resultsd
		HUS	D	A	Vero+, EIA+, VTEC- RPLA+	Vero+, EIA−, VTEC- RPLA+	Vero+, EIA−, VTEC- RPLA−	Vero−, EIA−, VTEC- RPLA−
stx2c	9e	5	2	2	7	2	0	0
stx2d	16f	0	5	11	11	0	0	5
stx2e	12g	0	8	4	7	1	3	1
Total	37	5	15	17	25	3	3	6

^aIsolated at the Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany, and at the Institute of Hygiene, University Hospital Münster, Münster, Germany, using a protocol described previously (3).

^bstx_2c, stx_2d, and stx_2e genotypes were determined as described previously (3); all 16 stx_2d-harboring strains contained an stx_2d allele which was amplified with primers VT2cm-VT2f (12) and encodes Stx2d not activatable by intestinal mucus (12); stx_{2d-activatable} (9) was absent from all 16 of these strains.

^cD, diarrhea; A, asymptomatic infection; HUS, hemolytic-uremic syndrome.

^dVero, Vero cell cytotoxicity assay; EIA, Stx enzyme immunoassay; VTEC-RPLA, latex agglutination assay; +, positive result; −, negative result.

^eSerotypes (number of strains, if more than one, in parentheses): O77:H⁻ (nonmotile), O23:H⁻, O30:HNT (H nontypeable), O60:H19, O92:HNT, O120:HNT, O145:H⁻ (2 strains), Orough (autoagglutinable):H⁻.

^fSerotypes (number of strains, if more than one, in parentheses): O40:H8 (6 strains), O86:H⁻, O91:H⁻ (2 strains), O146:H28 (2 strains), Orough:H45, Orough:HNT, ONT (O nontypeable):H12, ONT:H32, ONT:HNT.

^gSerotypes (number of strains, if more than one, in parentheses): O8:HNT, O60:H2, O60:H⁻ (2 strains), ONT:H⁻ (8 strains).