Identification and characterization of an aadB gene cassette at a secondary site in a plasmid from Acinetobacter

Abstract

Transformation studies showed that an aminoglycoside resistance gene, aadB, is carried on a 6.0-kb plasmid (pRAY) in a clinical isolate of Acinetobacter (strain SUN). The gene was cloned and sequenced. An analysis of the DNA sequencing data showed that although the aadB gene is part of cassette, it is not associated with an integron. Rather, the aadB cassette has recombined at a secondary site downstream of putative promoters on pRAY.