RESUMO
The high rates of carbapenem resistance among Brazilian Pseudomonas aeruginosa isolates are mainly associated with the clone ST277 producing the carbapenemase SPM-1. Here, the complete genetic composition of a IncP plasmid harboring blaKPC-2 in isolates of this endemic clone carrying chromosomal blaSPM-1 was described using whole genome sequencing. These results confirm the association of these two carbapenemases in ST277 and also describe the genetic composition of a novel blaKPC-2-plasmid. Considering the fact that this association occurs in a high-risk clone, monitoring the dissemination of this plasmid should be a public health concern.
Assuntos
Infecções por Pseudomonas , Pseudomonas aeruginosa , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Brasil/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa/genética , beta-Lactamases/genéticaRESUMO
BACKGROUND: The Brazilian endemic clone Pseudomonas aeruginosa ST277 carries important antibiotic resistance determinants, highlighting the gene coding for SPM-1 carbapenemase. However, the resistance and persistence of this clone is apparently restricted to the Brazilian territory. To understand the differences between Brazilian strains from those isolated in other countries, we performed a phylogenetic analysis of 47 P. aeruginosa ST277 genomes as well as analyzed the virulence and resistance gene profiles. Furthermore, we evaluated the distribution of genomic islands and assessed in detail the characteristics of the CRISPR-Cas immunity system in these isolates. RESULTS: The Brazilian genomes presented a typical set of resistance and virulence determinants, genomic islands and a high frequency of the CRISPR-Cas system type I-C. Even though the ST277 genomes are closely related, the phylogenetic analysis showed that the Brazilian strains share a great number of exclusively SNPs when compared to other ST277 genomes. We also observed a standard CRISPR spacers content for P. aeruginosa ST277, confirming a strong link between sequence type and spacer acquisition. Most CRISPR spacer targets were phage sequences. CONCLUSIONS: Based on our findings, P. aeruginosa ST277 strains circulating in Brazil characteristically acquired In163 and PAGI-25, which can distinguish them from strains that do not accumulate resistance mechanisms and can be found on the Asian, European and North American continents. The distinctive genetic elements accumulated in Brazilian samples can contribute to the resistance, pathogenicity and transmission success that characterize the ST277 in this country.
Assuntos
Proteínas de Bactérias/genética , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , beta-Lactamases/genética , Brasil/epidemiologia , Sistemas CRISPR-Cas , Células Clonais , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Resistência Microbiana a Medicamentos/genética , Genoma Bacteriano , Ilhas Genômicas , Humanos , Filogenia , Polimorfismo de Nucleotídeo Único , Pseudomonas aeruginosa/patogenicidadeRESUMO
OBJECTIVES: The purpose of this study was to investigate the resistome of an SPM-1-producing Pseudomonas aeruginosa ST277 isolate (HC84) from Brazil. METHODS: 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. RESULTS AND CONCLUSION: 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.