Characterization of gyrA mutations associated with fluoroquinolone resistance in Campylobacter coli by DNA sequence analysis and MAMA PCR.

Increasing numbers of fluoroquinolone-resistant Campylobacter coli isolates received at the Minnesota State Public Health Laboratory and at the Centers for Disease Control and Prevention have been a cause for concern. The gyrA quinolone resistance-determining regions of several fluoroquinolone-resistant isolates were sequenced to examine the mechanism of resistance. Ciprofloxacin-resistant C. coli isolates examined by DNA sequencing had a Thr-86 to Ile (ACT-->ATT) gyrA mutation, leading to resistance to fluoroquinolone antibiotics. A mismatch amplification mutation assay polymerase chain reaction protocol was developed to detect this gyrA mutation.