RESUMO
This study used whole-genome sequencing (WGS) and PFGE to analysis KPC-2-producing Klebsiella pneumoniae strains from clinical specimens collected in Brazilian hospitals. The study identifies the emergence of a novel small IncX3 plasmid (pKPB11), 12,757-bp in length, in a high-risk K. pneumoniae ST11/CG258 lineage, a successful clonal group in Brazil, carrying the blaKPC-2 gene on a non-Tn4401 genetic element (NTEKPC-Ic). Comparative analysis of the pKPB11 showed that this plasmid reduced its size, losing part of its conjugation apparatus. The pKPB11 was also compared to another strain sequenced in this study (KPC89) that had the hybrid IncX3-IncU plasmid (pKP89), of approximately 45 kb in length, similarly carrying the blaKPC-2 gene on NTEKPC-Ic. To the best of our knowledge, pKPB11 is the first example of small IncX3 plasmid found in a high-risk KPC-2-producing K. pneumoniae ST11/CG258.
Assuntos
Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Plasmídeos/genética , beta-Lactamases/genética , Brasil/epidemiologia , Ordem dos Genes , Genoma Bacteriano , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Infecções por Klebsiella/epidemiologia , Tipagem de Sequências MultilocusRESUMO
blaKPC-2 is disseminated worldwide usually in Tn4401, a Tn3-family transposon, and primarily in Klebsiella pneumoniae ST258, a well-known lineage that is distributed worldwide and responsible for several outbreaks. Although occurring rarely, blaKPC-2 has been described in non-Tn4401 elements (NTEKPCs), first in China and then in a few other countries. This study reports the dissemination of a blaKPC-2-carrying NTEKPC among ST11/CG258 K. pneumoniae strains and ST1642 K. quasipneumoniae subsp. quasipneumoniae AMKP9 in an Amazonian hospital. The dissemination was due to pAMKP10, an ~48 kbp IncX5 plasmid carrying ΔISKpn6/blaKPC-2/ISKpn27 in a Tn1722-based unit. Although similar to NTEKPC-Ia from pKP048 described in China, a different transposase is present upstream of ISKpn27. Additionally, mutations were identified downstream of ISKpn27 but did not affect the blaKPC-2 promoter regions. pAMKP10 conjugated in vitro only from CG258 isolates. Since CG258 strains are generally well adapted to the hospital environment, it is significant that pAMKP10 has found its way into this clinically significant clonal group. The impact of inter- and intraspecies dissemination of NTEKPCs and IncX5 plasmids harboring carbapenem resistance genes is unknown, but monitoring these plasmids could reveal their dissemination preferences.