Genomic analysis of the emergence and evolution of multidrug resistance during a Klebsiella pneumoniae outbreak including carbapenem and colistin resistance

Abstract

Carbapenem resistance required production of the DHA-1 β-lactamase and decreased permeability, but fosfomycin resistance depended only on permeability. Resistance to colistin might be related to an alteration in the regulation of the phoPQ system. Hypermutation is not related to the selection of porin mutants. Plasmid instability might be due to the high number of mobile elements and suggests a major role for antibiotic selection pressure in the emergence and evolution of this outbreak.