Expansion and Evolution of a Virulent, Extensively Drug-Resistant (Polymyxin B-Resistant), QnrS1-, CTX-M-2-, and KPC-2-Producing Klebsiella pneumoniae ST11 International High-Risk Clone

Autor(es)

Andrade, Leonardo Neves ^[1] ; Vitali, Lucia ^[2] ; Gaspar, Gilberto Gambero ^[2] ; Bellissimo-Rodrigues, Fernando ^[2] ; Martinez, Roberto ^[2] ; Costa Darini, Ana Lucia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Med Ribeirao Preto, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Clinical Microbiology; v. 52, n. 7, p. 2530-2535, JUL 2014.
• Citações Web of Science: 57

Resumo

In this study, we report the early expansion, evolution, and characterization of a multiresistant Klebsiella pneumoniae clone that was isolated with increasing frequency from inpatients in a tertiary-care university hospital in Brazil. Seven carbapenem-and quinolone-resistant and polymyxin B-susceptible or -resistant K. pneumoniae isolates isolated between December 2012 and February 2013 were investigated. Beta-lactamase-and plasmid-mediated quinolone resistance (PMQR)-encoding genes and the genetic environment were investigated using PCR, sequencing, and restriction fragment length polymorphism ( RFLP). Clonal relatedness was established using XbaI-pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and phylogenetic group characterization. Plasmid analyses included PCR-based replicon typing (PBRT) and hybridization of the S1-PFGE product, plasmid MLST, and conjugation experiments. Virulence potential was assessed by PCR by searching for 10 virulence factor-encoding genes (ureA, fimH, kfuBC, uge, wabG, magA, mrkD, allS, rmpA, and cf29a) and by phenotypic tests to analyze the hypermucoviscous phenotype. The genetic context of a multidrug-resistant and extensively drug-resistant K. pneumoniae ST11-KpI clone harboring IncFIIk-Tn4401a-bla(KPC-2), qnrS1, and bla(CTX-M-2) was found. Moreover, three isolates displayed high resistance to polymyxin B (MICs = 32, 32, and 128 mg/liter) as well as mucous and hypermucoviscous phenotypes. These bacteria also harbored ureA, fimH, uge, wabG, and mrkD, which code for virulence factors associated with binding, biofilm formation, and the ability to colonize and escape from phagocytosis. Our study describes the association of important coresistance and virulence factors in the K. pneumoniae ST11 international high-risk clone, which makes this pathogen successful at infections and points to the quick expansion and evolution of this multiresistant and virulent clone, leading to a pandrug-resistant phenotype and persistent bacteria in a Brazilian hospital. (AU)

• Processo FAPESP: 12/14740-3 - Investigação molecular de linhagens de Klebsiella pneumoniae e plasmídeos carreando genes codificadores de beta-lactamases
• Beneficiário: Ana Lúcia da Costa Darini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/08892-2 - Investigação molecular de linhagens de Klebsiella pneumoniae e plasmídeos carreando genes codificadores de beta-lactamases
• Beneficiário: Leonardo Neves de Andrade
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado