Molecular Evaluation of Fluoroquinolone Resistance in Serial Mycobacterium tuberculosis Isolates from Individuals Diagnosed with Multidrug-Resistant Tuberculosis.

Fluoroquinolones (FQ) are crucial components of multidrug-resistant tuberculosis (MDR TB) treatment. Differing levels of resistance are associated with specific mutations within the uinolone-esistance-etermining egion (QRDR) of We sequenced the QRDR from serial isolates of MDR TB patients in the Preserving Effective TB Treatment Study (PETTS) with baseline FQ resistance (FQ) or acquired FQ resistance (FQ) using an Ion Torrent Personal Genome Machine (PGM) to a depth of 10,000× and reported single nucleotide polymorphisms in ≥1% of reads. FQ isolates harbored 15 distinct alleles with 1.