Characterization of Mutations in DNA Gyrase and Topoisomerase IV Involved in Quinolone Resistance of Mycoplasma gallisepticum Mutants Obtained In Vitro

Mycoplasma gallisepticum enrofloxacin-resistant mutants were generated by stepwise selection in increasing concentrations of enrofloxacin. Alterations were found in the quinolone resistance-determining regions of the four target genes encoding DNA gyrase and topoisomerase IV from these mutants. This is the first description of such mutations in an animal mycoplasma species.