Int J Syst Evol Microbiol
January 2010
A bacterium, designated strain DC-196(T), isolated from kitchen refuse compost was analysed by using a polyphasic approach. Strain DC-196(T) was characterized as a Gram-negative short rod that was catalase- and oxidase-positive, and able to grow at 10-40 degrees C, pH 6-9 and in NaCl concentrations as high as 3 %. Chemotaxonomically, C(18 : 1) was observed to be the predominant cellular fatty acid and ubiquinone 10 (Q10) was the predominant respiratory quinone.
View Article and Find Full Text PDFWe investigated the impact of highly purified Haemophilus ducreyi cytolethal distending toxin (HdCDT) on the apoptosis and necrosis of various human cells; including myeloid cells, epithelial cells, keratinocytes, and primary fibroblasts. The levels of apoptosis and necrosis induced in these cells were compared to those induced by HdCDT in human T cells and in the Jurkat T cell line. Levels of caspase-3 activity were measured, and membrane changes like phosphatidylserine (PS) translocation was evaluated after double-staining with the fluorescein isothiocyanate (FITC)-labeled annexin V and propidium iodide (PI) using flow cytometry.
View Article and Find Full Text PDFBackground: The etiological agent is usually not established in cases of genital ulcer disease (GUD) in Tanzania, since diagnosis and treatment of this disease are based mainly on clinical rather than microbiologic parameters. GUD increases the risk of infection with HIV. However, the association between specific GUD infections and HIV infection has not been fully investigated.
View Article and Find Full Text PDFThe cytolethal distending toxin of Haemophilus ducreyi (HdCDT) is a three-component toxin that induces the arrest of the mammalian cell cycle in the G2 phase. All of the individual gene products, CdtA, CdtB and CdtC, are required for toxic activity on cultured mammalian cells. The CdtB component alone exerts nuclease activity.
View Article and Find Full Text PDFHaemophilus ducreyi, the etiologic agent of the sexually transmitted disease chancroid, produces a cytolethal distending toxin (HdCDT) that inhibits mammalian cell proliferation. We investigated the effects of HdCDT on normal human endothelial cells and on tubule formation in an in vitro model of angiogenesis. Endothelial cells were arrested in the G2 phase of the cell cycle, and tubule formation was inhibited in a dose-dependent manner.
View Article and Find Full Text PDFWe investigated the phagocytosis of Haemophilus ducreyi both in vitro and in vivo. Human granulocyte and monocyte phagocytosis of opsonized and nonopsonized, fluorescence-labeled H. ducreyi was assessed by flow cytometry.
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