Interspecies recombination occurs frequently in quinolone resistance-determining regions of clinical isolates of Streptococcus pyogenes

Fluoroquinolone resistance in Streptococcus pyogenes has been reported only anecdotally, but a recent Belgian surveillance study found a rate of nonsusceptibility of 5.4%. From an analysis of these isolates, we show that interspecies horizontal gene transfer within the parC quinolone resistance-determining region is a frequent phenomenon that might contribute to fluoroquinolone resistance. Copyright © 2008, American Society for Microbiology. All Rights Reserved.