Abstract
Background: We found three copies of blaKPC-2 on a plasmid of a Klebsiella pneumoniae strain and report the findings here.
Methods: A carbapenem-resistant K. pneumoniae clinical strain, SCEC020002, was subjected to whole genome sequencing using both short-read Illumina X10 platform and long-read MinION sequencer. Hybrid assembly was performed using Unicycler and contigs were then corrected using Plion. Based on the whole genome sequence, sequence type, capsular type, plasmid replicon type and plasmid multi-locus sequence type were determined and virulence and antimicrobial resistance genes were identified. Mating was performed to obtain a self-transmissible plasmid mediating carbapenem resistance.
Results: Strain SCEC020002 was resistant to imipenem (MIC, 64 μg/ml) and meropenem (128 μg/ml). This strain SCEC020002 had a 5,477,148-bp circular chromosome, two small ColRNAI-like plasmids (5,596-bp and 10,060-bp, and one large plasmid (177,508-bp, designated pKPC2_020002) containing an IncR and an FII replicon. Surprisingly, there are three copies of the carbapenemase-gene blaKPC-2 on pKPC2_020002, which was not self-transmissible. Each of the blaKPC-2 genes was located in the same genetic context with insertion sequence ISKpn27 upstream and ISKpn6 downstream, which was bracketed by IS26. The three copies of the IS26-ISKpn27- blaKPC-2-ISKpn6-IS26 unit were present in tandem.
Conclusion: We report the surprising co-existence of three copies of blaKPC-2 on an IncR/IncF plasmid, which was due to the action of IS26. Multiple copies of IS26 are one key factor to generate genetic plasticity and could mediate the multiplication of resistance genes.
Methods: A carbapenem-resistant K. pneumoniae clinical strain, SCEC020002, was subjected to whole genome sequencing using both short-read Illumina X10 platform and long-read MinION sequencer. Hybrid assembly was performed using Unicycler and contigs were then corrected using Plion. Based on the whole genome sequence, sequence type, capsular type, plasmid replicon type and plasmid multi-locus sequence type were determined and virulence and antimicrobial resistance genes were identified. Mating was performed to obtain a self-transmissible plasmid mediating carbapenem resistance.
Results: Strain SCEC020002 was resistant to imipenem (MIC, 64 μg/ml) and meropenem (128 μg/ml). This strain SCEC020002 had a 5,477,148-bp circular chromosome, two small ColRNAI-like plasmids (5,596-bp and 10,060-bp, and one large plasmid (177,508-bp, designated pKPC2_020002) containing an IncR and an FII replicon. Surprisingly, there are three copies of the carbapenemase-gene blaKPC-2 on pKPC2_020002, which was not self-transmissible. Each of the blaKPC-2 genes was located in the same genetic context with insertion sequence ISKpn27 upstream and ISKpn6 downstream, which was bracketed by IS26. The three copies of the IS26-ISKpn27- blaKPC-2-ISKpn6-IS26 unit were present in tandem.
Conclusion: We report the surprising co-existence of three copies of blaKPC-2 on an IncR/IncF plasmid, which was due to the action of IS26. Multiple copies of IS26 are one key factor to generate genetic plasticity and could mediate the multiplication of resistance genes.
Original language | English |
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Journal | Journal of Global Antimicrobial Resistance |
DOIs | |
Publication status | Published - 26 Nov 2018 |
Keywords
- carbapenem resistance
- plasmids
- KPC-2
- klebsiella pneumoniae