Novel Mechanism for Fluoroquinolone Resistance in Acinetobacter baumannii

Abstract

ABSTRACTAn EZ::TN<R6Kγori/KAN-2>Tnp transposon insertion in an open reading frame of unknown function (ncr) inAcinetobacter baumanniiresulted in an 8-fold increase in ciprofloxacin resistance (Cipr). Transposon insertions in anncrmutant that reduced Ciprback to wild type mapped to three genes encoding subunits of the RecCBD exonuclease. Thencrmutation increased transcription of therecCBDgenes, and overexpression of therecCBDgenes in a wild-type background resulted in a 4-fold increase in Cipr.