Temporal evolution of polymyxin B-resistant Klebsiella pneumoniae clones recovered from blood cultures in a teaching hospital during a 7-year period.
The polymyxins have become one of the last resorts to treat serious infections caused by KPC-2-producing Klebsiella pneumoniae worldwide. However, the increase of polymyxin consumption has favored the emergence of resistance to these compounds. In this study, we observed an increase in polymyxin B resistance rates from 0 to 30.6% among 224 K. pneumoniae isolates recovered from blood cultures between 2009 and 2015. Only gentamicin, tigecycline and fosfomycin remained active against the polymyxin B-resistant K. pneumoniae (PMB-R-KPN) isolates, which were classified as extensively drug-resistant (XDR; 83.3%), multidrug-resistant (MDR; 13.9%), or pan-drug resistant (2.8%). Most PMB-R-KPN clones belonged to CC258 (ST11, ST258, ST340, and ST437). A C7/ST258 XDR clone carrying distinct resistance determinants (blaSHV-11, blaTEM-1, blaCTX-M-15, blaCTX-M-14, blaKPC-2, and rmtB-1) was introduced in 2014. Twelve of 36 PMB-R-KPN isolates showed disruption of mgrB. No mcr-1-positive isolate was found. The rapid detection of PMB-R-KPN isolates allied to implementation of effective infection control measures are of crucial importance to avoid the dissemination of high-risk PMB-R-KPN clones.
['Braun|Graziela|G|', 'Cayô|Rodrigo|R|', 'Matos|Adriana Pereira|AP|', 'de Mello Fonseca|Juliane|J|', 'Gales|Ana Cristina|AC|']
D000900:Anti-Bacterial Agents D016470:Bacteremia D000073537:Biological Variation, Population D000071997:Blood Culture D003428:Cross Infection D024881:Drug Resistance, Bacterial D019143:Evolution, Molecular D014644:Genetic Variation D005838:Genotype D006784:Hospitals, Teaching D006801:Humans D007710:Klebsiella Infections D007711:Klebsiella pneumoniae D008826:Microbial Sensitivity Tests D058889:Molecular Typing D011112:Polymyxin B
Extensively drug-resistance Beta-lactamase Enterobacteriaceae Gram-negative bacilli, carbapenemase Hospital infection Molecular epidemiology