SPM-1-producing Pseudomonas aeruginosa ST277 carries a chromosomal pack of acquired resistance genes: An example of high-risk clone associated with 'intrinsic resistome'.

Abstract

The purpose of this study was to investigate the resistome of an SPM-1-producing Pseudomonas aeruginosa ST277 isolate (HC84) from Brazil. Whole-genome sequencing of P. aeruginosa HC84 was performed using an Ion Proton™ System. De novo assembly was carried out using CLC Genomics Workbench 8.0, and gene prediction was performed using the Prokka pipeline. Here we describe the resistome of SPM-1-producing P. aeruginosa ST277 (HC84) consisting of 13 different antimicrobial resistance genes [blaSPM-1, rmtD, aacA4, aadA7, blaOXA-56, blaOXA-396, blaPAO, aph(3')-IIb, aac(6')-Ib-cr, crpP, catB7, cmx and fosA). This particular chromosomal pack of resistance genes is strongly associated with clonal dissemination and suggests an important role in the persistence of this clone in Brazilian nosocomial infections. For that reason, could we already consider the 'chromosomal pack of acquired resistance genes' like an 'ST277 intrinsic resistome'? This is an example of chromosomal accumulation of acquired resistance genes as well as integrative and conjugative elements into a successful bacterial pathogen and calls attention to the evolution of other species driving to insertion and persistence of multiple acquired resistance genes in the bacterial chromosome.