Table 2. Frequency distribution of predominant SBI genotypes of Shiga toxin–producing Escherichia coli O157:H7 isolates obtained from humans, bovine fecal samples, and bovine meat samples, New Zealand, 2008–2011*.
| Isolate type, SBI type | No. with SBI
type/no. total (%) |
p value† | |
|---|---|---|---|
| North Island | South Island | ||
| Human | |||
| AY2a | 175/278 (62.9) | 35/85 (41.2) | <0.001 |
| WY12a | 41/278 (14.7) | 9/85 (10.6) | |
| ASY2c/SY2c | 49/278 (17.6) | 35/85 (41.2) | |
| Other |
13/278 (4.7) |
6/85 (7.1) |
|
| Bovine fecal | |||
| AY2a | 22/32 (68.8) | 0/8 | <0.001 |
| WY12a | 6/32 (18.8) | 0/8 | |
| ASY2c/SY2c |
1/32 (3.1) |
8/8 (100.0) |
|
| Bovine meat | |||
| AY2a-like | 137/201 (68.2) | 15/34 (44.1) | <0.001 |
| WY12a-like | 49/201 (24.4) | 6/34 (17.6) | |
| ASY2c/SY2c-like | 15/201 (7.5) | 13/34 (38.2) | |
*SBI, Shiga toxin–encoding bacteriophage insertion. †Values refer to differences between frequency distributions of SBI types and North and South Islands (χ2 and Fisher exact test).