A double mutation in the gyrA gene is necessary to produce high levels of resistance to moxifloxacin in Campylobacter spp. clinical isolates.

The aim of this study was to compare different fluoroquinolones against Campylobacter spp., analysing the molecular mechanisms of resistance. Moxifloxacin exhibited the greatest activity of the quinolones tested, being active against isolates carrying a single mutation in the gyrA gene. High resistance levels to moxifloxacin were related to the presence of a double gyrA mutation.