ISApl4, a New IS1595 Family Insertion Sequence Forming a Novel Pseudo-Compound Transposon That Confers Antimicrobial Multidrug Resistance in Actinobacillus pleuropneumoniae
Janine T. Bossé, Yanwen Li, Marc Stegger, Liza Miriam Cohen, Øystein Angen, Søren Overballe-Petersen, Dennis Hanke, Stefan Schwarz, Paul R. Langford and Henrike Krüger-Haker
Background/Objectives: Actinobacillus pleuropneumoniae is an important respiratory tract pathogen of swine worldwide. Insertion sequences (ISs) play a major role in the transfer of antimicrobial resistance (AMR) among various porcine respiratory tract pathogens. In this study, three A. pleuropneumoniae genomes were investigated for the presence of a novel IS. Methods: Analysis of the draft genomes of three A. pleuropneumoniae serovar 8 isolates (AP_1, AP_120, AP_123) suggested the presence of a novel IS. A closed whole-genome sequence was generated for strain AP_123 by hybrid assembly of Oxford Nanopore MinION long-reads and Illumina MiSeq short-reads, followed by sequence analysis using standard online tools. Transfer was tested by natural transformation. Antimicrobial susceptibility testing was conducted by broth microdilution following Clinical and Laboratory Standards Institute standards. Results: A novel IS, designated ISApl4, was detected in all three genomes. ISApl4 is 712 bp in size and has a transposase gene (tnp) of 654 bp. Moreover, it has perfect terminal 14-bp inverted repeats and produces 8-bp direct repeats at its integration site. This IS was found in 39 copies in the AP_123 genome, two of which formed the 5,765-bp pseudo-compound transposon Tn7560. This transposon carries four AMR genes: sul2 (sulfonamide resistance), strA-strB (streptomycin resistance), and tet(Y) (tetracycline resistance). RT-PCR confirmed tnp gene expression and horizontal transfer of Tn7560 into A. pleuropneumoniae MIDG2331. Conclusions: This study identified the novel ISApl4 in porcine A. pleuropneumoniae and its association with the novel pseudo-compound transposon Tn7560, which proved to be an active element capable of disseminating multidrug resistance amongst A. pleuropneumoniae.
Details
Title
ISApl4, a New IS1595 Family Insertion Sequence Forming a Novel Pseudo-Compound Transposon That Confers Antimicrobial Multidrug Resistance in Actinobacillus pleuropneumoniae
Authors/Creators
Janine T. Bossé - Imperial College London
Yanwen Li - Imperial College London
Marc Stegger - Murdoch University
Liza Miriam Cohen - Norwegian University of Life Sciences
Øystein Angen - Statens Serum Institut
Søren Overballe-Petersen - Statens Serum Institut
Dennis Hanke - Freie Universität Berlin
Stefan Schwarz - Freie Universität Berlin
Paul R. Langford - Imperial College London
Henrike Krüger-Haker - Freie Universität Berlin
Publication Details
Antibiotics (Basel), Vol.14(10), 1021
Publisher
MDPI
Number of pages
18
Grant note
SCHW382/17-1 / German-Israeli Foundation for Scientific Research and Development (501100001736)
BB/S005897/1 / Biotechnology and Biological Sciences Research Council (501100000268)
BB/S002103/1 / Biotechnology and Biological Sciences Research Council (501100000268)