Characterization of a mutation in the parE gene that confers fluoroquinolone resistance in Streptococcus pneumoniae

We report a mutation in the parE genes of two in vitro mutants of Streptococcus pneumoniae responsible for low-level resistance to fluoroquinolones. Sequential acquisition of mutations in parE and gyrA leads to higher levels of resistance. This confirms that topoisomerase IV is the primary target of fluoroquinolones in S. pneumoniae.