Full characterization of an IncR plasmid harboring qnrS1 recovered from a VIM-11-producing Pseudomonas aeruginosa

摘要

Metallo-β-lactamases (MBL) producingPseudomonas aeruginosaisolates have been well characterized. Quinolones are commonly used in the treatment of carbapenem-resistantP. aeruginosainfections; however, data about PMQR in this species are scarce. The objective of this study was to report the simultaneous presence ofqnrSandblaVIM-11inP. aeruginosa, and to characterize theqnrS-harboring plasmid.Thirty-eight carbapenem-resistantP. aeruginosaisolates were recovered from a hospital in Buenos Aires during 2012. Screening for MBL was assessed by the double disk synergy test using EDTA and carbapenem discs. Plasmid DNA extraction was performed by a method using phenol-chloroform. PCR followed by sequencing was carried out to determine each MBL and PMQR allele. PCR-BseGI-RFLP was performed to detectaac-(6′)-Ib-cr. ThegyrA-QRDR was sequenced in those PMQR-harboring isolates. Plasmid incompatibility groups and addiction systems were characterized by PCR. The PMQR-carrying plasmid was sequenced using Illumina technology, annotated using RAST and manually curated.Eleven/38 isolates were VIM producers (blaVIM-2andblaVIM-11) while 1/38 harboredblaIMP-13. One isolate harboredblaVIM-11and the PMQRqnrS1; however, both markers were located in different plasmids.TheqnrS1-harboring plasmid (pP6qnrS1) was 117945bp in size, presented 154 CDS and corresponded to the IncR group. In addition toqnrS1, it harbored several aminoglycoside resistance markers. Although pP6qnrS1 was non-conjugative, it presented anoriTwhich made it possible for this plasmid to be transferable.This is the first report onP. aeruginosacarrying bothblaVIM-11andqnrS1, plus the first detection of an IncR plasmid in Argentina.