TABLE 2.
CT produced by pIG in El Tor strains
| Strain [relevant genotype] | CT productiona in:
|
|
|---|---|---|
| LB | AKI medium | |
| E7946 [wild-type] | <0.01 | 2.3 |
| Bah-2 (pIG) [RF] | 0.7 | 0.8 |
| Bah-2 [CTXφ−] | <0.01 | <0.01 |
| Bah-2-55 (pIG) [toxR]b | 0.8 | 0.8 |
| E7946-55 [toxR]b | <0.01 | <0.01 |
| Bah-2 (pSL1) [ΔSphI]c | 0.01 | 0.08 |
a
Cells were incubated in the medium indicated (supplemented with kanamycin for strains harboring pIG or pSL1) at 37°C. Toxin amounts are expressed in micrograms per unit of optical density at 600 nm. Values represent the averages of at least three independent experiments.
b
[toxR], inactivated toxR gene.
c
pSL1 is a derivative of pIG which contains a deletion of the SphI site in orfU.