Molecular Analysis of Polymyxin Resistance among Carbapenemase-Producing Klebsiella pneumoniae in Colombia

Autores organización

• 

  Elsa Piedad De La Cadena Vivas

  Autor

• Maria Fernanda Mojica Medina

  Autor

• 

  Juan Carlos Garcia Betancur

  Autor

• 

  Christian Jose Pallares Gutierrez

  Autor

• 

  Maria Virginia Villegas Botero

  Autor

Autores

• Appel, TM
• Porras, J
• Solano-Gutiérrez, JS
• Rojas, LJ

Grupos de investigación

• Grupo de Investigación en Resistencia Antimicrobiana y Epidemiología Hospitalaria RAEH

  

  Investigador

  Maria Virginia Villegas Botero

Resumen

Polymyxin resistance in Klebsiella pneumoniae has been attributed to mutations in mgrB, phoPQ, pmrAB, and crrAB and to the presence of mcr plasmid-mediated genes. Herein, we describe the molecular characteristics of 24 polymyxin- and carbapenem-resistant K. pneumoniae isolates recovered from six Colombian cities between 2009 and 2019. Minimum inhibitory concentrations (MICs) to polymyxin were confirmed by broth microdilution, and whole-genome sequencing was performed to determine sequence type, resistome, and mutations in the genes related to polymyxin resistance, as well the presence of mcr. The results showed high-level resistance to polymyxin (MICs >= 4 mu g/mL). bla(KPC-3) was present in the majority of isolates (17/24; 71%), followed by bla(KPC-2) (6/24; 25%) and bla(NDM-1) (1/24; 4%). Most isolates belonged to the CG258 (17/24; 71%) and presented amino acid substitutions in PmrB (22/24; 92%) and CrrB (15/24; 63%); mutations in mgrB occurred in only five isolates (21%). Additional mutations in pmrA, crrA, and phoPQ nor any of the mcr resistance genes were identified. In conclusion, we found clonal dissemination of polymyxin and carbapenem-resistant K. pneumoniae isolates in Colombia, mainly associated with CG258 and bla(KPC-3). Surveillance of this multidrug-resistant clone is warranted due to the limited therapeutic options for the treatment of carbapenem-resistant K. pneumoniae infections.

Keywords

• Klebsiella pneumoniae; multidrug resistance; polymyxins; whole-genome sequencing