Abstract
Purpose: :
To assess the relationship between mutations in the gyrA gene and quinolone resistance in ophthalmic clinical isolates of Corynebacterium species
Methods: :
Ten strains of Corynebacterium species were isolated at Tokushima University Hospital, JAPAN. Five of the ten were susceptible to quinolones, CPFX, NFLX and LVFX, but the rests were resistant to these drugs. The MICs of CPFX, NFLX and LVFX were determined by the method of E–test. The nucleotide sequence of quinolone resistance determining regions was characterized using the amplified gyrA gene of those strains by PCR method.
Results: :
All five quinolone–resistant strains showed mutation leading to an amino acid change in position 83 and 87 of gyrA. Whereas amino acid change in 83 Ser to Leu was a common characteristic in all strains, some variations were seen in 87 Asp to Asn, His or Gly. The MICs of NFLX for all quinolone–resistant strains tend to depend on the variation.
Conclusions: :
The mutations in the gyrA gene of Corynebacterium species seen in position 83 and 87 are related to the mechanism of quinolone resistance.
Keywords: antibiotics/antifungals/antiparasitics • gene/expression