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Aims:  To develop a PCR‐based method for reliable detection of Escherichia coli that enables its differentiation from biochemically and phylogenetically related bacteria. Methods and Results:  Using multiplex PCR targeting four genes (cytochrome bd complex, lactose permease, β‐d‐glucuronidase, and β‐d‐galactosidase) the possibility of specific detection of various control E. coli strains was tested. It was found that four PCR fragments of the predicted size were observed only for E. coli strains, but not for relatives as close as Shigella sp. or other enterobacteria. Not surprisingly, this method enabled us to identify also E. coli strains which did not exhibit the β‐d‐glucuronidase activity. Our multiplex PCR was also successfully used for identification of 95 environmental isolates of E. coli. Conclusions:  The developed PCR‐based method, in which four genes coding for lactose permease, cytochrome bd complex, β‐d‐glucuronidase, and β‐d‐galactosidase, serve as target DNA sequences, allows precise and reliable detection of E. coli strains. Significance and Impact of the study:  The suggested approach increases the specificity of detection of E. coli since it enables to distinguish E. coli from Shigella sp. and other relative enterobacteria.

Treatment of tobacco BY-2 cells with micromolar concentration of benzyladenosine ([9R]

As an extension of our recently published work (Mlejnek and Kuglík [2000] J. Cell. Biochem. 77:6-17), the role of caspases in N(6)-benzylaminopurine riboside (BAPR)-induced apotosis in HL-60 cells was evaluated in this study. Here, BAPR-induced apoptosis was accompanied by activation of caspase-3 and caspase-9. However, when these caspases were selectively inhibited, the progression of BAPR-induced apoptosis was not markedly affected. Besides that, activation of caspase-3 and caspase-9 was found to be rather late event in apoptotic process. These results suggested that other caspases might be critically implicated. Indeed, pan-specific caspase inhibitor, Z-VAD-FMK, completely prevented DNA cleavage and apoptotic bodies formation. However, Z-VAD-FMK failed to prevent cell death and it was incapable to fully counteract the main apoptotic hallmark-chromatin condensation. Finally, our data indicate that cellular decision between apoptosis and necrosis is made upon the availability of both caspase proteases and intracellular ATP.