Multiclonal Expansion of Klebsiella pneumoniae Isolates Producing NDM-1 in Rio de Janeiro, Brazil

We characterized NDM-1-producingKlebsiellaisolates from Rio de Janeiro, Brazil. PCR was applied for resistance and virulence determinants. The genetic context ofblaNDMwas determined by S1 nuclease pulsed-field gel electrophoresis (PFGE) and hybridization. Genotyping was performed by PFGE and multilocus sequence typing (MLST). Most isolates carried multiple resistance genes and remained susceptible to amikacin, fosfomycin-trometamol, polymyxin B, and tigecycline. The spread of NDM-1-producingKlebsiella pneumoniaewas not associated with clonal expansion and appears to be associated with Tn3000.