Table 6. Incidence of virulence genes in all O157 and non-O157 STEC isolatesa.
| Number of O157 STEC isolates (% of total) | ||||||||
| Sample source | Total recovered | stx1 | stx2 | stx1/stx2b | fliC | eae | hlyA | |
| Domestic ruminantsc | 541 | 200 (37) | 522 (96) | 181 (33) | 541 (100) | 54 (100) | 541 (100) | |
| Wildlife (feces) | 40 | 22 (55) | 40 (100) | 22 (55) | 40 (100) | 40 (100) | 40 (100) | |
| Wildlife (swabs) | 12 | 0 (0) | 12 (100) | 0 (0) | 12 (100) | 12 (100) | 12 (100) | |
| Soil | 5 | 5 (100) | 5 (100) | 5 (100) | 5 (100) | 5 (100) | 2 (40) | |
| Produce | 0 | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |
| Waterd | 60 | 35 (58) | 60 (100) | 35 (58) | 60 (100) | 60 (100) | 59 (98) | |
| Sediment | 12 | 8 (67) | 12 (100) | 8 (67) | 12 (100) | 12 (100) | 12 (100) | |
| Total | 670 | 270 (40) | 651 (97) | 251 (37) | 670 (100) | 670 (100) | 666 (99) | |
| Number of Non-O157 STEC isolates (% of total) | ||||||||
| Sample source | Total recovered | stx 1 | stx 2 | stx 1/ stx 2 a | sub A | eae | ehx A | |
| Domestic ruminants | 2,590 | 1,605 (62) | 1,944 (75) | 962 (37) | 754 (29) | 577 (23) | 2,103 (82) | |
| Wildlife (feces) | 304 | 246 (81) | 245 (80) | 97 (32) | 91 (30) | 76 (25) | 219 (72) | |
| Wildlife (swabs) | 49 | 13 (26) | 47 (96) | 5 (10) | 5 (10) | 26 (53) | 18 (37) | |
| Soil | 20 | 5 (25) | 19 (95) | 4 (20) | 3 (15) | 5 (25) | 8 (40) | |
| Produce | 60 | 25 (41) | 47 (77) | 12 (20) | 34 (56) | 5 (8.2) | 48 (79) | |
| Water | 187 | 120 (64) | 101 (54) | 36 (19) | 29 (16) | 94 (50) | 150 (80) | |
| Sediment | 74 | 62 (84) | 46 (62) | 34 (46) | 15 (20) | 28 (38) | 63 (85) | |
| Total | 3,284 | 2076 (63) | 2449 (74) | 1150 (35) | 931 (28) | 811 (25) | 2609 (79) | |
a
Represents isolates saved after screening a larger number of isolates by stx-PCR, O-typing ELISA, MLVA and ompA sequencing. Data from this characterization facilitated selection of isolates to represent those from an individual sample and minimize replication of strains from a sample. STECs isolated by all 3 methods are included.
b
Both stx1 and stx2 present in the same strain.
c
Cattle, alpaca, goats.
d
Isolates from any water sample are included.