Production of High Levels of Bacillus Anthracis Toxin Antigens in a New, Defined Culture Medium

Ristroph, Joseph D.; Ivins, Bruce E.

doi:10.21236/ada116827

Cited by 33 publications

(41 citation statements)

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“…Bicarbonate medium contained NBY with the addition of 0.8% Na 2 HCO 3 and 10% 0.1-mm-filtered equine serum (Hyclone). Phage assay (PA) medium, modified G (mG) medium and R medium were prepared as described previously (Kim and Goepfert, 1974;Ristroph and Ivins, 1983;Welkos and Marrero, 1996). For solid media, 15 g of agar (BD Biosciences) was added per litre of medium.…”

Section: Bacterial Strains and Mammalian Cell Linesmentioning

confidence: 99%

Early Bacillus anthracis-macrophage interactions: intracellular survival and escape

et al. 2000

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This study describes early intracellular events occurring during the establishment phase of Bacillus anthracis infections. Anthrax infections are initiated by dormant endospores gaining access to the mammalian host and becoming engulfed by regional macrophages (Mφ). During systemic anthrax, late stage events include vegetative growth in the blood to very high titres and the synthesis of the anthrax exotoxin complex, which causes disease symptoms and death. Experiments focus on the early events occurring during the first few hours of the B. anthracis infectious cycle, from endospore germination up to and including release of the vegetative cell from phagocytes. We found that newly vegetative bacilli escape from the phagocytic vesicles of cultured Mφ and replicate within the cytoplasm of these cells. Release from the Mφ occurs 4–6 h after endospore phagocytosis, timing that correlates with anthrax infection of test animals. Genetic analysis from this study indicates that the toxin plasmid pXO1 is required for release from the Mφ, whereas the capsule plasmid pXO2 is not. The transactivator atxA, located on pXO1, is also found to be essential for release, but the toxin genes themselves are not required. This suggests that Mφ release of anthrax bacilli is atxA regulated. The putative ‘escape’ genes may be located on the chromosome and/or on pXO1.

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Section: Bacterial Strains and Mammalian Cell Linesmentioning

confidence: 99%

Early Bacillus anthracis-macrophage interactions: intracellular survival and escape

et al. 2000

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“…Effect of medium composition. Medium composition, including the presence or absence of bicarbonate, is known to influence the synthesis of the three anthrax toxin components (19), and this regulation occurs at the level of transcription for pag (1). Thus, we used our three transcriptional fusion-carrying strains to examine toxin gene expression in various media.…”

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confidence: 99%

“…Analysis was initially carried out during growth at 370C in synthetic R medium (19) in the presence or absence of bicarbonate (Fig. 3).…”

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confidence: 99%

The three Bacillus anthracis toxin genes are coordinately regulated by bicarbonate and temperature

1994

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The two BaciUlls anthracis toxins are composed of three proteins, protective antigen, lethal factor, and edema factor. The structural genes for these three components are located on the virulence plasmid pXOl. We constructed transcriptional fusions between the regulatory region of each of these genes and acZ. Each construct was then inserted as a single copy at the corresponding toxin gene locus on pXOl, resulting in three isogenic strains. Two environmental factors, bicarbonate and temperature, were found to induce 3-galactosidase synthesis in each recombinant strain. Furthermore, the transcription of the three toxin genes appears to be coordinately regulated.

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“…Cultures were grown in sealed flasks containing RM-medium [27] for 18-20 h, which coincided with stationary phase growth [33]. Two isolates, 17T5 and Zimbabwe, required longer growth times (24-26 h) or a heavier inoculum to achieve sufficient growth within 18-20 h (data not shown).…”

Section: Resultsmentioning

confidence: 99%

Western blot analysis of the exotoxin components from Bacillus anthracis separated by isoelectric focusing gel electrophoresis

Little

2004

Biochemical and Biophysical Research Communications

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Production of High Levels of Bacillus Anthracis Toxin Antigens in a New, Defined Culture Medium

Cited by 33 publications

References 0 publications

Early Bacillus anthracis-macrophage interactions: intracellular survival and escape

Early Bacillus anthracis-macrophage interactions: intracellular survival and escape

The three Bacillus anthracis toxin genes are coordinately regulated by bicarbonate and temperature

Western blot analysis of the exotoxin components from Bacillus anthracis separated by isoelectric focusing gel electrophoresis

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