The aim of the project is to make more accurate (on the basis of genome analysis) diagnostics of coagulase-negative staphylococci Staphylococcus hominis, S. epidermidis and S. haemolyticus causing nosocomial infections. By means of quantitative PFGE-macr orestriction analysis, hybridization techniques including ribotyping, PCR, and plasmid analysis, the genomic variability of these multiple-resistant strains will be estimated. Genetic relationship among the strains found by DNA analysis will be correlate d with the phenotypic properties of these strains. The strains of these species are multiple-resistant and they occur particularly in blood cultures. The proposed project is highly topical and comes up to current trends in diagnostics of bacterial pathog ens causing epidemiological problems. Its extraordinary significance is especially in the active help to clinical practise and in the effectiveness of human health protection. The results of the proposed project should give a complex view to the genomic