Multiclonal Outbreak of Klebsiella pneumoniae Producing Extended-Spectrum β-Lactamase CTX-M-2 and Novel Variant CTX-M-59 in a Neonatal Intensive Care Unit in Brazil

An outbreak of cephalosporin-resistant Klebsiella pneumoniae occurred in a neonatal intensive care unit in São Paulo, Brazil. Of the 10 pulsotypes identified during the outbreak and follow-up periods, nine produced CTX-M-2 or its new variant CTX-M-59 and one produced SHV-5. bla(CTX-M-2/59) genes were located on closely related plasmids that were transferable.