[Usefulness of plasmids as epidemiologic markers for typing of Klebsiella]

The study was aimed at evaluation of utility of plasmids as epidemiological markers for interspecific differentiation of 200 strains of Klebsiella isolated from patients with generalized infections and hospitalized at intensive care ward of the Gdańsk Medical Academy. Strains isolated from the ward environment were also investigated. In the first phase of this study classical methods of typing were used, such as determination of the biochemical, bacteriocin (susceptibility to 8 bacteriocins) and phage types, and MIC for 9 antibiotics. Basing on these methods it was found that 41 types of Klebsiella pneumoniae, 13 types of Klebsiella oxytoca and 1 type of Klebsiella ozenae occur. Six groups of bacteria were differentiated in the group which had the same type. These strains were investigated for plasmid and restrictive patterns. Identity of types occurring in individual groups was detected. For one of them, a restrictive pattern was determined by cleavage of plasmid DNA by a restrictive Eco RV enzyme. In remaining groups such pattern was not found, both after treatment with Eco RV and Hha I enzyme and this may be associated with modification of the plasmid DNA. Strains belonging to one of these groups did not contain plasmids in their cells.