Jaroslav Spížek

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High occurrence of the non-macrolide-lincosamide-streptogramin B resistance genes msrA (53%) and linA/linA' (30%) was found among 98 methicillin-resistant coagulase-negative staphylococci additionally resistant to macrolides and/or lincosamides. The gene msrA predominated in Staphylococcus haemolyticus (43 of 62 isolates). In Staphylococcus epidermidis, it(More)
Adenylate cyclase activity was detected and characterized in cell-free preparations of different strains ofEscherichia coli; it was localized not only in the membrane fraction but also in the cytoplasm, the localization differing from strain to strain. The adenylate cyclase activity is highly dependent on the method used for disintegration of cells. The(More)
The LmbB1 protein, participating in the biosynthesis of lincomycin, was heterologously expressed in Escherichia coli, purified in its active form, and characterized as a dimer of identical subunits. Methods for purification and analysis of the LmbB1 reaction product were developed. Molecular mass and fragmentation pattern of the product revealed by(More)
Copy numbers of the streptomycete plasmid vector pRS410 and five other recombinant plasmid derivatives of the original cryptic streptomycete plasmid pSLG33 were determined using calibrated laser densitometry. DNA preparations, electrophoretically separated on agarose gels, were stained with ethidium bromide, photographed and the negatives were subsequently(More)
Acetolactate synthase small subunit encoding ilvN genes from the parental Streptomyces cinnamonensis strain and mutants resistant either to valine analogues or to 2-ketobutyrate were cloned and sequenced. The wild-type IlvN from S. cinnamonensis is composed of 175 amino acid residues and shows a high degree of similarity with the small subunits of other(More)
Acetohydroxy-acid synthases (AHAS) of two mutant strains Streptomyces cinnamonensis ACB-NLR-2 and BVR-18 were chosen for this study for their apparent activation by valine, which regularly acts as an allosteric inhibitor. Sequencing the ilvB genes coding for the AHAS catalytic subunit revealed two distant changes in the mutants, ΔQ217 and E139A,(More)
Dental caries is a highly prevalent multifactorial disease that can result in serious health impairment. It was shown that oral bacteria play a significant role in caries development. Point-of-care (POC) salivary microbial tests for detection of cariogenic species have been investigated as a potential tool for caries risk assessment. This review aims to(More)
The genes lmbA,B1,B2 in the lincomycin A production gene cluster of Streptomyces lincolnensis were shown to form a common transcription unit with the promoter located directly upstream of lmbA. The proteins LmbB1 (mol. mass, 18 kDa) and LmbB2 (mol. mass 34 kDa), when over-produced together in Escherichia coli, brought about enzyme activities for the(More)
We determined the activities of new antibiotics telithromycin (ketolide) and quinupristin/dalfopristin (streptogramins) against 88 macrolide and/or lincosamide resistant coagulase-negative staphylococci (CoNS) isolates with defined resistance gene status. Telithromycin susceptibility was determined only in erythromycin-sensitive isolates (15) indicating the(More)