TABLE 1.
Frequency of E. coli strains encoding colicin Ia, microcin V, or both bacteriocins, together with the predicted fraction of strains encoding both bacteriocins assuming that they randomly associatea
| Source and group | No. of isolates | % Observed
|
% Predicted, colicin Ia and microcin V | P > χ2 | ||
|---|---|---|---|---|---|---|
| Colicin Ia | Microcin V | Colicin Ia and microcin V | ||||
| Human | ||||||
| A | 90 | 4.4 | 3.3 | 6.6 | 1.1 | <0.001 |
| B1 | 51 | 9.8 | 7.8 | 2.0 | 1.1 | 0.575 |
| B2 | 350 | 3.7 | 2.3 | 7.1 | 1.0 | <0.001 |
| D | 128 | 4.7 | 2.7 | 3.1 | 0.4 | <0.001 |
| Animal | ||||||
| A | 93 | 2.2 | 1.1 | 0 | <0.1 | 0.834 |
| B1 | 272 | 6.2 | 1.8 | 1.1 | <0.1 | <0.001 |
| B2 | 213 | 17.8 | 0.1 | 2.3 | <0.1 | <0.001 |
| D | 112 | 6.2 | 0 | 0 | ||
a
Data presented are for strains isolated from humans and nonhuman vertebrates living in Australia with respect to the genetic group membership of the strains.