Table 3.

In vitro site-directed mutagenesis of H. pylori 23S rRNA gene and MLS phenotypes of the mutants obtained

Mutation in PCR fragmentNo. of transformants obtainedNo. of transformants sequencedMutation in 23S rRNA geneMIC (μg/ml)a
ClaClnQnp
Wild type0Wild type0.004324
G2141A0NKNKNK
A2142G>1,0008A2142G16>512128
A2142C>1,0003A2142C16>512128
A2142Cb 1A2142C/T8>512128
A2142T>1,0004A2142T451264
A2143G>1,0004A2143G42564
A2143C>1,0003A2143C42564
A2143Cc 1A2143C + A2142G16>512128
A2143T0NKNKNK
  • 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).