TABLE 3.
Numbers and percentages of noninvasive diarrheagenic E. coli strains utilizing heme and hemoglobin and possessing iron uptake genes
| Category and subgroup | No. tested | No. (%) of strains showing:
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Heme utilization | Hemoglobin utilization | FeCl 3 utilization | chuA | iucA | fepC (PAI)a | ireA | iroN | hbp | ||
| EAEC (reference strains) | 21 | 19 (90.5) | 19 (90.5) | 21 (100) | 7 (33.3) | 16 (76.2) | 7 (33.3) | 0 (0) | 0 (0) | 0 (0) |
| EHEC and other Shiga toxin- producing E. coli strains | ||||||||||
| O157 | 3 | 3 (100) | 3 (100) | 3 (100) | 3 (100) | 0 (0) | 3 (100) | 0 (0) | 0 (0) | 0 (0) |
| Non-O157 | 13 | 3 (23.1) | 10 (7.69) | 13 (100) | 0 (0) | 6 (46.2) | 0 (0) | 1 (7.7) | 0 (0) | 0 (0) |
| EPEC | ||||||||||
| EPEC1 | 18 | 11 (61.11) | 17 (94.4) | 18 (100) | 17 (94.4) | 1 (5.6) | 15 (83.3) | 0 (0) | 0 (0) | 0 (0) |
| EPEC2 | 12 | 3 (25.0) | 11 (91.7) | 12 (100) | 1 (8.3) | 0 (0) | 1 (8.3) | 0 (0) | 0 (0) | 0 (0) |
| Non-EPEC, non-EHEC attaching and effacing E. colib | 4 | 0 (0) | 4 (100) | 4 (100) | 0 (0) | 1 (25.0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| ETEC | 23 | 20 (87.0) | 21 (91.3) | 23 (100) | 0 (0) | 0 (0) | 9 (39.1) | 0 (0) | 4 (17.4) | 0 (0) |
| DAEC | 16 | 4 (25.0) | 10 (62.5) | 16 (100) | 1 (6.3) | 2 (12.5) | 1 (6.3) | 4 (25.0) | 4 (25.0) | 5 (31.3) |
a
PAI, pathogenicity island.
b
One strain each of porcine, rabbit, canine, and human origin.