Amplification of aminoglycoside resistance gene aphA1 in Acinetobacter baumannii results in tobramycin therapy failure.

ABSTRACT: Gene amplification is believed to play an important role in antibiotic resistance but has been rarely documented in clinical settings because of its unstable nature. We report a rise in MICs from 0.5 to 16 μg/ml in successive Acinetobacter baumannii isolated over 4 days from a patient being treated with tobramycin for an infection by multidrug-resistant A. baumannii, resulting in therapeutic failure. Isolates were characterized by whole-genome sequencing, real-time and reverse transcriptase PCR, and growth assays to determine the mechanism of tobramycin resistance and its fitness cost. Tobramycin resistance was associated with two amplification events of different chromosomal fragments containing the aphA1 aminoglycoside resistance gene part of transposon Tn6020. The first amplification ev

SUBMITTER: McGann P 

PROVIDER: S-EPMC3994513 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature