TABLE 3.
In vitro site-directed mutagenesis of H. pylori 23S rRNA gene and MLS phenotypes of the mutants obtained
| Mutation in PCR fragment | No. of transformants obtained | No. of transformants sequenced | Mutation in 23S rRNA gene | MIC (μg/ml)a
|
||
|---|---|---|---|---|---|---|
| Cla | Cln | Qnp | ||||
| Wild type | 0 | Wild type | 0.004 | 32 | 4 | |
| G2141A | 0 | NK | NK | NK | ||
| A2142G | >1,000 | 8 | A2142G | 16 | >512 | 128 |
| A2142C | >1,000 | 3 | A2142C | 16 | >512 | 128 |
| A2142Cb | 1 | A2142C/T | 8 | >512 | 128 | |
| A2142T | >1,000 | 4 | A2142T | 4 | 512 | 64 |
| A2143G | >1,000 | 4 | A2143G | 4 | 256 | 4 |
| A2143C | >1,000 | 3 | A2143C | 4 | 256 | 4 |
| A2143Cc | 1 | A2143C + A2142G | 16 | >512 | 128 | |
| A2143T | 0 | NK | NK | NK | ||
a
Abbreviations: Cla, clarithromycin; Cln, clindamycin; Qnp, quinupristin; NK, not known.
b
Of the four transformants picked up for sequencing, one contained an A2142C/T mutation (both C and T bands of equal intensities were revealed on the sequencing gel [see Fig. 2]).
c
Of the four transformants picked up for sequencing, one contained a double mutation (A2143C and A2142G).