Please use this identifier to cite or link to this item:
Title: Integrase-Controlled Excision of Metal-Resistance Genomic Islands in Acinetobacter baumannii.
Authors: Al-Jabri, Z
Zamudio, R
Horvath-Papp, E
Ralph, JD
Al-Muharrami, Z
Rajakumar, K
Oggioni, MR
First Published: 20-Jul-2018
Publisher: MDPI
Citation: Genes 2018, 9(7), 366
Abstract: Genomic islands (GIs) are discrete gene clusters encoding for a variety of functions including antibiotic and heavy metal resistance, some of which are tightly associated to lineages of the core genome phylogenetic tree. We have investigated the functions of two distinct integrase genes in the mobilization of two metal resistant GIs, G08 and G62, of Acinetobacter baumannii. Real-time PCR demonstrated integrase-dependent GI excision, utilizing isopropyl β-d-1-thiogalactopyranoside IPTG-inducible integrase genes in plasmid-based mini-GIs in Escherichia coli. In A. baumannii, integrase-dependent excision of the original chromosomal GIs could be observed after mitomycin C induction. In both E. coli plasmids and A. baumannii chromosome, the rate of excision and circularization was found to be dependent on the expression level of the integrases. Susceptibility testing in A. baumannii strain ATCC 17978, A424, and their respective ΔG62 and ΔG08 mutants confirmed the contribution of the GI-encoded efflux transporters to heavy metal decreased susceptibility. In summary, the data evidenced the functionality of two integrases in the excision and circularization of the two Acinetobacter heavy-metal resistance GIs, G08 and G62, in E. coli, as well as when chromosomally located in their natural host. These recombination events occur at different frequencies resulting in genome plasticity and may participate in the spread of resistance determinants in A. baumannii.
DOI Link: 10.3390/genes9070366
ISSN: 2073-4425
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © the authors, 2018. This is an open-access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Description: The following are available online at, Table S1: List of primers, Figure S1: Standard curves for the qPCR.
Appears in Collections:Published Articles, Dept. of Genetics

Files in This Item:
File Description SizeFormat 
2018 Al_Jabri Genes.pdfPublished (publisher PDF)2.34 MBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.