National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Clinical and microbiological characteristics of community strains of Staphylococcus lugdunensis
PETŘÍKOVÁ, Barbora
The bachelor thesis is focused on characterization of coagulase-negative staphylococcus. Staphylococcus lugdunenis is considered to be an opportunist pathogen, which is able to cause an infection in healthy individuals, as only one of few existing CNS. The aim of this thesis is to sum up actual knowledge about a clinical importace, basic characteristic and possibilities of laboratory diagnostics of the species Staphylococcus lugdunensis. The initial chapter of this bachelor thesis is dedicated to a description of staphylococcus and its distribition to a positive and a negative clumbing factor. In the thesis is described its morphology and further the detailed characteristic of Staphylococcus lugdunensis, its microbiological characteristic and identification possibilities with assistance of different biochemical tests Methodical part of the thesis was carried out in the laboratory Stafila Ltd. I was watching the finding of Staphylococcus lugdunensis in this laboratory during one year (January December 2016). In this part is described a differentiation of staphylococcus to staphylococcus clumbing factor positive and staphylococcus clumbing factor negative. Then follows an identification of species which is focused on the species of Staphylococcus lugdunensis. The species identification was carried out with a commercial test STAPHYtest24. Then I concentrated on description of all tests which are used in this laboratory for an exact identification S. lugdunensis, e,g. HYA test, PYR test and others. For species which were identified as Staphylococcus lugdunensis was carried out a test for susceptibility to antibiotics using a method of disc diffusion sensitivity. Further is a practical part of this thesis dedicated to comparison of species Staphylococcus aureus and Staphylococcus lugdunensis. The comparison of these two species confirmed, as expected, that a presence of Staphylococcus aureus is much higher than S. lugdunensis, but infections caused by S. lugdunensis are from clinical point of view very similar to them where was proved a pathogen S. aureus.
Molecular analysis of resistance gene vga(A)LC identification of key aminoacid residues.
Kroová, Michaela ; Najmanová, Lucie (advisor) ; Vopálenský, Václav (referee)
Protein Vga(A) gives staphylococci resistance to streptogramins A. The recently discovered protein Vga(A)LC differs from Vga(A) only by 7 amino acid residues, but this difference is sufficient for shift of its substrate specificity towards lincosamides. The group of four amino acids in the central part of protein (LGAG in Vga(A) and SVTS in Vga(A)LC) was detected to be crucial for the substrate specificity. In this diploma thesis 5 alternativesets of vga(A)LC gene point mutations were prepared in order to determine the impact of individual amino acids of the aforementioned group on the resistance phenotype. Mutations were prepared in vector pGEM® -T and cloned into shuttle vector pRB374. The prepared constructs were transformed by electroporation into the sensitive strain of Staphylococcus aureus RN4220 and values of minimum inhibitory concentration (MIC) were measured for lincomycin, clindamycin and pristinamycin IIA by the agar dilution method. The transformation was not successful in one of the mutations. Results of setting MIC for the remaining four mutations do not make it possible to specify uniquely the ratio of individual amino acids for determining substrate specificity. Two of the amino acids were found to be important. We anticipate preparation of more mutations.

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