Emergence and dissemination of colistin-resistant Klebsiella pneumoniae isolates expressing OXA-48 plus CTX-M-15 in patients not previously treated with colistin in a Spanish university hospital
Por:
Barragán-Prada H, Ruiz-Hueso P, Tedim AP, González-Candelas F, Galán JC, Cantón R and Morosini MI
Publicada:
1 feb 2019
Resumen:
Dissemination of multidrug-resistant Klebsiella pneumoniae in the hospital environment represents a primary target of resistance containment and stewardship programs. At present, polymyxins, mostly in combination, exemplify a last-resort alternative. Colistin-resistant K. pneumoniae isolates harboring OXA-48 plus CTX-M-15 (n = 21) with the simultaneous colistin-susceptible counterparts (n = 9) were recovered from 14 hospitalized patients (January 2014-January 2015) admitted in different wards. In most cases, patients had not previously received colistin. Genetic relatedness experiments demonstrated that 93% (28/30) of isolates belonged to the ST11 high-risk clone. Heteroresistance and the fitness cost of colistin resistance were addressed in susceptible and resistant isolates as well as in in vitro-obtained stable mutants, and results appeared to be strain dependent. Whole genome sequencing demonstrated molecular changes in pmrA, pmrB, and mgrB genes. Plasmid-mediated colistin resistance genes were not found. Colistin resistance in multidrug-resistant K. pneumoniae isolates should be continuously monitored to detect its potential emergence, even in patients not previously exposed to colistin. (C) 2018 Elsevier Inc. All rights reserved.
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