We previously demonstrated point mutations in the quinolone resistance determining regions (QRDR) of a DNA gyrase gene (gyrA) and a topoisomerase gene (parC) of fluoroquinolone resistant Streptococcus pyogenes. Further sequencing and data analysis has revealed additional point mutations beyond the QRDR of gyrA and parC. These mutations appear to play no role in the resistance of Streptococcus pyogenes to fluoroquinolone antibiotics.
