RESUMO
Klebsiella pneumoniae is a major threat to public health with the emergence of isolates resistant to most, if not all, useful antibiotics. We present an in-depth analysis of 178 extended-spectrum beta-lactamase (ESBL)-producing K. pneumoniae collected from patients resident in a region of Pakistan, during the period 2010-2012, when the now globally-distributed carbapenemase bla-NDM-1 was being acquired by Klebsiella. We observed two dominant lineages, but neither the overall resistance profile nor virulence-associated factors, explain their evolutionary success. Phenotypic analysis of resistance shows few differences between the acquisition of resistance genes and the phenotypic resistance profile, including beta-lactam antibiotics that were used to treat ESBL-positive strains. Resistance against these drugs could be explained by inhibitor-resistant beta-lactamase enzymes, carbapenemases or ampC type beta-lactamases, at least one of which was detected in most, but not all relevant strains analysed. Complete genomes for six selected strains are reported, these provide detailed insights into the mobile elements present in these isolates during the initial spread of NDM-1. The unexplained success of some lineages within this pool of highly resistant strains, and the discontinuity between phenotypic resistance and genotype at the macro level, indicate that intrinsic mechanisms contribute to competitive advantage and/or resistance.
Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Infecções por Klebsiella , Klebsiella pneumoniae , Inibidores de beta-Lactamases , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/patogenicidade , Paquistão , Virulência , Inibidores de beta-Lactamases/farmacologia , Inibidores de beta-Lactamases/uso terapêutico , beta-Lactamases/efeitos dos fármacosRESUMO
Klebsiella pneumoniae shows increasing emergence of multidrug-resistant lineages, including strains resistant to all available antimicrobial drugs. We conducted whole-genome sequencing of 178 highly drug-resistant isolates from a tertiary hospital in Lahore, Pakistan. Phylogenetic analyses to place these isolates into global context demonstrate the expansion of multiple independent lineages, including K. quasipneumoniae.
