Characterization of class 1 integron resistance gene cassettes and the identification of a novel IS-like element in Acinetobacter baumannii.
Based on hybridization studies, 21/32 multi-resistant clinical isolates of Acinetobacter baumannii contain class 1 integrons. Amplification products were obtained from 20 of the hybridization-positive strains. A single dfrA7 cassette was identified in 18 of the isolates and an integron with two cassettes (aadB-aadA4) was found in only one strain. Amplicons were not obtained from one of the hybridization positive strains. DNA sequence analysis of a 6.080-kb fragment, cloned from this strain, identified the remnant of an integron, following insertion of IS26 into the 5(')-end of intI1. The 6.080-kb sequence carries an aminoglycoside resistance gene, linked to a portion of IS1133, which in turn is linked to a sequence that has properties of IS elements, including sequences that could stimulate transcription, and ORFs encoding amino acid sequences with similarity to a transposase from Deinococcus radiodurans.
Department of Medical Microbiology, Medical School, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa.
Heidi
H
Segal
Robin
R
Thomas
B
B
Gay Elisha
D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D014644:Genetic Variation; D017403:In Situ Hybridization; D032023:Integrons / Q000187:drug effects / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D012689:Sequence Homology, Nucleic Acid; D013019:South Africa
D000900:Anti-Bacterial Agents