Inactivation of the oprD porin gene by a novel insertion sequence ISPa195 associated with large deletion in a carbapenem-resistant Pseudomonas aeruginosa clinical isolate.

Autor: Bocharova Y; National Medical Research Center for Children's Health, Lomonosovskiy av., 2a, Moscow, Russia. Electronic address: ivrin7@gmail.com., Savinova T; National Medical Research Center for Children's Health, Lomonosovskiy av., 2a, Moscow, Russia., Shagin DA; Central Research Institute of Epidemiology, Novogireevskaya st., 3a, Moscow, Russia., Shelenkov AA; Central Research Institute of Epidemiology, Novogireevskaya st., 3a, Moscow, Russia., Mayanskiy NA; National Medical Research Center for Children's Health, Lomonosovskiy av., 2a, Moscow, Russia., Chebotar IV; Central Research Institute of Epidemiology, Novogireevskaya st., 3a, Moscow, Russia.
Jazyk: angličtina
Zdroj: Journal of global antimicrobial resistance [J Glob Antimicrob Resist] 2019 Jun; Vol. 17, pp. 309-311. Date of Electronic Publication: 2019 Jan 23.
DOI: 10.1016/j.jgar.2019.01.016
Abstrakt: Objectives: Alteration of the porin-encoding gene oprD by insertion sequences (ISs) is one mechanism conferring carbapenem resistance in Pseudomonas aeruginosa. Here we describe a carbapenem-resistant clinical P. aeruginosa isolate 36-989 harbouring a novel IS (ISPa195) in oprD.
Methods: Minimum inhibitory concentrations (MICs) of antimicrobial agents were determined by the broth microdilution method. Carbapenemase activity was assessed using a MALDI-TOF/MS-based assay of meropenem hydrolysis. Efflux-dependent carbapenem resistance was evaluated using an assay with carbonyl cyanide 3-chlorophenylhydrazone (CCCP). The oprD gene and IS sequence were analysed by the Sanger method. Whole-genome sequencing was performed on an Illumina HiSeq 2500 platform.
Results: Antimicrobial susceptibility testing demonstrated that P. aeruginosa 36-989 was resistant to imipenem (MIC=32mg/L) and meropenem (MIC=16mg/L). No carbapenemase activity was detected, however an efflux-mediated component of carbapenem resistance was revealed. A new IS element (ISPa195) was found in the oprD gene of P. aeruginosa 36-989. ISPa195 was 1190bp in length, belonging to the IS3 family, and contained two open reading frames that overlapped through a ribosomal slippage to translate the full-size transposase enzyme. There was an IS-associated 284-bp deletion in the oprD gene; no direct repeats at flanking regions of the IS were detected.
Conclusion: The absence of direct repeats at flanking regions in combination with the IS-associated deletion distinguished ISPa195 from other ISs previously detected in oprD. Carbapenem resistance in P. aeruginosa 36-989 was conferred by a combination of oprD alteration and carbapenem efflux.
(Copyright © 2019 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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