New sequence type in multidrug-resistant Klebsiella pneumoniae harboring the bla(NDM-1)-encoding gene in Brazil

Objectives: The aim of this study was to investigate the bla(NDM) gene, pathogenic potential, and antimicrobial resistance of clinical isolates of carbapenem-resistant Klebsiella pneumoniae isolated from patients admitted to the University Hospital of Londrina between January 2014 and March 2017. Methods: bla(NDM-1) and virulence genes were investigated using conventional PCR methods Antimicrobial susceptibility testing was performed by disk diffusion method according to the Clinical and Laboratory Standards Institute guidelines of 2017. Clonal relationships of the New Delhi metallo-beta-lactamase (NDM)-positive isolates were determined by enterobacterial repetitive intergenic consensus (ERIC)-PCR and multilocus sequence typing (MLST). Results: A total of 825 K. pneumoniae were identified, with four isolates (Kp6408, Kp6410, Kp6411, and Kp6715) presenting the bla(NDM-1) gene. All NDM-1-producing isolates showed co-production of bla(KPC-2) and bla(TEM) genes and also the virulence genes kfu, entB, mrkD, and fimH. Three isolates (Kp6408, Kp6410, and Kp6715) were classified as multidrug-resistant (MDR) and one (Kp6411) as extensively drugresistant (XDR). ERIC-PCR analyses demonstrated that the isolates shared about 60% genetic similarity. MLST revealed four different sequence types (STs), described for the first time in Brazil, with two novel STs described in this study: ST3371 and ST3372. Conclusion: This study reports the identification of NDM-1 associated with KPC and virulence genes in four MDR K. pneumoniae with STs first described in Brazil. (c) 2018 State University of Londrina. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). (AU)