TABLE 1.
Distribution of cdt-I, cdt-II, cdt-III, cdt-IV, and cdt-V alleles among 340 non-O157 STEC strainsa
| Serotype(s)b | Total no. of isolates | No. of isolates PCR positive for:
|
|||||
|---|---|---|---|---|---|---|---|
| eae | cdt-I | cdt-II | cdt-III | cdt-IV | cdt-Vc | ||
| O26:H11/H−d | 40 | 40 | 0 | 0 | 0 | 0 | 0 |
| O103:H2/H− | 23 | 23 | 0 | 0 | 0 | 0 | 0 |
| O111:H8/H− | 14 | 14 | 0 | 0 | 0 | 0 | 0 |
| O145:H28/H25/H− | 23 | 23 | 0 | 0 | 0 | 0 | 0 |
| Otherse | 30 | 30 | 0 | 0 | 0 | 0 | 0 |
| O8:H2/H10/H14/H19/H28/H− | 11 | 0 | 0 | 0 | 0 | 0 | 0 |
| O73:H18 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
| O91:H14/H− | 14 | 0 | 0 | 0 | 0 | 0 | 0 |
| O91:H21 | 15 | 0 | 0 | 0 | 0 | 0 | 9 |
| O113:H4 | 11 | 0 | 0 | 0 | 0 | 0 | 0 |
| O113:H21 | 6 | 0 | 0 | 0 | 0 | 0 | 4 |
| O128:H2/H12/H− | 13 | 0 | 0 | 0 | 0 | 0 | 0 |
| O146:H8/H10/H21/H28/H31/ H51/H− | 20 | 0 | 0 | 0 | 0 | 0 | 0 |
| O153:H18 | 3 | 0 | 0 | 0 | 3 | 0 | 0 |
| O174:H2/H8/H21/H− | 11 | 0 | 0 | 0 | 0 | 0 | 0 |
| Othersf | 105 | 0 | 0 | 0 | 0 | 0 | 0 |
The strains were isolated at the Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, at the Institute of Hygiene, University Hospital Münster, Münster, and at the Robert Koch Institute, Wernigerode, Germany, between 1996 and 2002 and serotyped as described previously (8, 21).
Only serotypes comprising cdt-positive strains and serogroups or serotypes with more than 10 isolates are listed in the table; the other serotypes are collectively called “Others.”
All 14 strains positive for cdt-V produced amplicons of expected sizes in each of the three PCRs for the detection of cdt-VA, cdt-VB, and cdt-VC (Table 2).
H−, nonmotile.
Serotypes (number of isolates, where more than one was used, in parentheses): O4:H−, O6:H− (2), O8:H2 (4), O11:H2, O25:H− (2), O55:H6, O84:H4/H6/H− (4), O92:H33, O118:H16/H− (3), O119:H2, O121:H10/H19 (2), O129:H−, O136:H−, O156:H−, O165:H−, Orough:H10 (Orough, autoagglutinable strain) (2), ONT:H11 (ONT, O antigen, nontypeable) (2).
Serotypes (number of isolates, where more than one was used, in parentheses): O3:H2/H10 (2), O4:H−, O5:H− (6), O6:H− (5), O15:H21, O22:H8 (6), O23:H19, O31:H−, O40:H8 (5), O41:H−, O62:H−, O68:H4, O74:H−, O75:H8, O76:H19 (8), O78:H− (3), O84:H4, O86:H− (2), O92:H−, O104:H16/H21 (3), O112:H2/H− (4), O115:H10 (2), O136:H2, O152:H4, O176:H−, O178:H19/H− (6), O181:H16/H49 (6), Orough:H2/H11/H19/H21/H45/H− (18), ONT:H2/H4/H10/H14/H18/H19/H21/H32/H− (15).