Ciprofloxacin resistance in Campylobacter jejuni isolates: detection of gyrA resistance mutations by mismatch amplification mutation assay PCR and DNA sequence analysis.

The gyrA quinolone resistance determining region was sequenced from 13 ciprofloxacin-resistant and 20 ciprofloxacin-susceptible Campylobacter jejuni isolates. All isolates resistant to ciprofloxacin had Thr-86-to-Ile mutations, a mutation frequently associated with the acquisition of resistance to fluoroquinolones. A mismatch amplification mutation assay (MAMA) PCR protocol was developed that detects this gyrA mutation in quinolone-resistant isolates. The MAMA PCR provides a means for routine detection of the gyrA mutation without the need for sequencing the gyrA gene.