Fluoroquinolone-resistant Streptococcus pneumoniae

摘要

To the Editor: In pneumococci,resistance to fluoroquinolones is asso-ciated with chromosomal mutations inthe quinolone-resistance–determiningregions (QRDR) of type II topoiso-merase enzymes, predominantly gyrAand parC. Several mutations havebeen described in these enzymes, butonly a few have been shown by invitro studies to confer resistance:S81F or Y, C, or I and E85K in gyrA;E474K in gyrB; A63T, S79F or Y or Land D83G or N in parC; and E474Kand D435N or H in parE (1–5). Otherfrequently described mutations areK137N in parC and I460V in parE,which appear to not contribute to flu-oroquinolone resistance because theyare commonly found in susceptiblestrains, and no evidence exists fortheir conferring fluoroquinoloneresistance in vitro. We describe here apneumococcal strain that was isolatedfrom a 66-year-old white man withchronic obstructive pulmonary dis-ease (COPD).