Survey of Klebsiella pneumoniae producing extended-spectrum beta-lactamases at a Portuguese hospital: TEM-10 as the endemic enzyme

One hundred and thirty-eight isolates of Klebsiella pneumoniae showing resi stance to ceftazidime were isolated from different wards of the Hospital de Santa Maria, Lisbon, The genomic DNA of the isolates was analysed by pulse d-field gel electrophoresis (PFGE) and two patterns were predominant. In al l isolates the presence of a single large plasmid of about 50 kb suggested that propagation of the outbreak prominently involved plasmid spread, The d educed amino acid sequence indicated the presence of a TEM-10 beta-lactamas e. This extended-spectrum P-lactamase was present among K. pneumoniae isola tes, was widely disseminated in different wards and remained persistent as a result of an outbreak involving the dissemination of both the multi-resis tance plasmids harbouring the bla gene and the isolates themselves.