Comparison of (GTG)5-oligonucleotide and ribosomal intergenic transcribed spacer (ITS)-PCR for molecular typing of Klebsiella isolates.

Molecular typing of Klebsiella species has become important for monitoring dissemination of β-lactamase-producers in hospital environments. The present study was designed to evaluate poly-trinucleotide (GTG)(5)- and rDNA intergenic transcribed spacer (ITS)-PCR fingerprint analysis for typing of Klebsiella pneumoniae and Klebsiella oxytoca isolates. Multiple displacement amplified DNA derived from 19 K. pneumoniae (some with an ESBL-phenotype), 35 K. oxytoca isolates, five K. pneumoniae, two K. oxytoca, three Raoultella, and one Enterobacter aerogenes type and reference strains underwent (GTG)(5) and ITS-PCR analysis. Dendrograms were constructed using cosine coefficient and the Neighbour joining method. (GTG)(5) and ITS-PCR analysis revealed that K. pneumoniae and K. oxytoca isolates, reference and type strains formed distinct cluster groups, and tentative subclusters could be established. We conclude that (GTG)(5) and ITS-PCR analysis combined with automated capillary electrophoresis provides promising tools for molecular typing of Klebsiella isolates.