TABLE 3.
Transformation frequencies of H. pylori wt and mutant strains
| H. pylori strain and mutation | Transformation frequency with:
|
|
|---|---|---|
| Chromosomal H. pylori DNA (str)a | Plasmid DNA (pDH29) (erm)b | |
| P1 | (1.3 ± 0.5) × 10−5 | (1.1 ± 0.3) × 10−5 |
| P12 | (1.3 ± 0.6) × 10−6 | (2.0 ± 0.9) × 10−5 |
| P12ΔcomB2 | <10−9 | <10−9 |
| P12ΔcomB3 | <10−9 | <10−9 |
| P1ΔcomB2-comB4 | <10−9 | <10−9 |
| P1ΔcomB2-comB4[pAK20] | (5.2 ± 1.1) × 10−6 | (3.4 ± 1.2) × 10−6 |
| P1ΔcomB2-comB4[pAK21] | <10−9 | <10−9 |
| P1ΔcomB2-comB4[pAK22] | <10−9 | <10−9 |
| P1ΔcomB6 | <10−9 | <10−9 |
| P1ΔcomB6-comB10 | <10−9 | <10−9 |
| P1ΔcomB6-comB10[pAK24] | (0.4 ± 0.1) × 10−7 | (1.9 ± 0.7) × 10−7 |
| P1ΔcomB6-comB10[pDHO46] | <10−9 | <10−9 |
| P149 | ND | (5.4 ± 1.9) × 10−4 |
| P149[hp1421::TnHK9] | ND | (3.8 ± 1.4) × 10−4 |
a
Chromosomal DNA from strain P12 (str) or P1 (str) was used for transformation. str, streptomycin resistance gene cassette. ND, not done.
b
Plasmid pDH29 was used for transformation. It consists of pBluescript plasmid with the H. pylori recA gene interrupted by an erm (erythromycin resistance) cassette (25).