Retrospective analysis of the genetic diversity of Klebsiella oxytoca isolated in Poland over a 50-year period

Abstract

Population genetics analyses and determination of the phylogenetic relationships between strains have proven to be extremely useful approaches, enabling deeper insights into the epidemiological pattern of bacterial species. There is no longitudinal data describing the molecular epidemiology of Klebsiella oxytoca strains that are opportunistic pathogens responsible for an increasing number of multi-resistant infections in hospitals. The aim of the present study was to assess the genetic diversity of K. oxytoca strains over a 50-year period using internal transcribed spacer polymerase chain reaction (ITS-PCR) and PCR MP (ang. PCR melting profiles) genotyping methods on a large collection of strains isolated from the patients of several hospitals in Poland. The phylogenetic analysis based on ITS-PCR exhibited six distinct branches. Two main groups, KoX and KoY, with four and two sub-groups within KoX and KoY, respectively, have been identified. Typing by the PCR MP method showed a higher level of genetic diversity. However, all K. oxytoca strains were also divided into six genotype groups (KoA, KoB, KoC, KoD, KoE and KoF). In conclusion, we found that the ITS-PCR and PCR MP methods are useful for the phylogenetic delineation of genetic groups in K. oxytoca.