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Bacillus anthracis

About: Bacillus anthracis is a research topic. Over the lifetime, 3994 publications have been published within this topic receiving 128122 citations.


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TL;DR: The data indicate that the Mac-1/BclA interaction may play a major role in B. anthracis pathogenesis by promoting spore uptake by professional phagocytes and subsequent access to a favorable niche for transport, germination, and outgrowth in lymphoid tissues.
Abstract: Anthrax, a disease caused by Bacillus anthracis, affects animals and humans. Because the inert spore is the infectious form of the organism that first contacts the potential host, the interaction between the host and spore exosporium is vital to the initiation of disease. Here, we demonstrate that the integrin Mac-1 is essential for the recognition of the major exosporium protein BclA by phagocytic cells. Expression of Mac-1, but not p150/95, in CHO cells markedly enhanced infection with Sterne strain of B. anthracis spores (WT spores). Conversely, CD11b−/− macrophages demonstrated a significant decrease in spore uptake when compared with macrophages from normal C57BL/6 mice. However, when CD11b−/− macrophages were infected with ΔbclA spores, spore ingestion was no different from their C57BL/6 counterparts. ΔbclA spores were also efficiently internalized by all CHO cell lines tested, independently of Mac-1 expression. Taken together, these results show that there is an alternative Mac-1-independent pathway involved in spore uptake that is unmasked only in the absence of BclA. Survival studies, using C57BL/6 and CD11b−/− mice, revealed that CD11b−/− mice are more resistant to infection with WT but not ΔbclA spores. Our experiments also show that ΔbclA spores are more virulent than WT spores in C57BL/6 and A/J mice. Overall, our data indicate that the Mac-1/BclA interaction may play a major role in B. anthracis pathogenesis by promoting spore uptake by professional phagocytes and subsequent access to a favorable niche for transport, germination, and outgrowth in lymphoid tissues.

99 citations

Journal ArticleDOI
TL;DR: A rapid and accurate detection system for environmental anthrax spores using real‐time PCR is established, avoiding time and labor‐consuming preparation steps such as enrichment culturing and DNA preparation.
Abstract: Quantitative analysis of anthrax spores from environmental samples is essential for accurate detection and risk assessment since Bacillus anthracis spores have been shown to be one of the most effective biological weapons. Using TaqMan real-time PCR, specific primers and probes were designed for the identification of pathogenic B. anthracis strains from pag gene and cap gene on two plasmids, pXO1 and pXO2, as well as a sap gene encoded on the S-layer. To select the appropriate lysis method of anthrax spore from environmental samples, several heat treatments and germination methods were evaluated with multiplex-PCR. Among them, heat treatment of samples suspended with sucrose plus non-ionic detergent was considered an effective spore disruption method because it detected up to 10(5) spores/g soil by multiplex-PCR. Serial dilutions of B. anthracis DNA and spore were detected up to a level of 0.1 ng/ microliters and 10 spores/ml, respectively, at the correlation coefficient of 0.99 by real-time PCR. Quantitative analysis of anthrax spore could be obtained from the comparison between C(T) value and serial dilutions of soil sample at the correlation coefficient of 0.99. Additionally, spores added to soil samples were detected up to 10(4) spores/g soil within 3 hr by real-time PCR. As a consequence, we established a rapid and accurate detection system for environmental anthrax spores using real-time PCR, avoiding time and labor-consuming preparation steps such as enrichment culturing and DNA preparation.

99 citations

Journal ArticleDOI
TL;DR: In this article, B. anthracis Sterne was grown from a live veterinary vaccine and used it to test for the development of resistance after 21 sequential subcultures in sub-inhibitory concentrations of doxycycline and three quinolones (ciprofloxacin, alatrofloxacan, and gatifloxacan).

99 citations

Journal ArticleDOI
TL;DR: Chlorination of anthracimycin gives a dichloro derivative that retains activity against Gram-positive bacteria, such as anthrax, but also shows activity against selected Gram-negative bacteria.
Abstract: The human infectious disease anthrax is caused by the sporeforming, Gram-positive bacterium Bacillus anthracis. The disease, which is most common in those that handle infected farm animals, has also been used as a bioterrorism weapon. In 2001, just a week after the World Trade Center attacks, anthrax was deliberately spread through the US postal system by sending letters with powdered B. anthracis spores. This caused 22 cases of anthrax infection and ultimately claimed five lives. [1] Depending upon the method of exposure (inhalation of spores and direct bacterial contact, among others) B. anthracis infections can require prolonged treatment often for six months with a variety of antibiotics. The pulmonary form of anthrax is considered a medical emergency that may require continuous intravenous therapy with potent antibiotics. In the event of a bioterrorism attack, individuals exposed to B. anthracis will be given antibiotics prior to the onset of the illness. A vaccine has been developed but is not yet available to the general public. [2] Given the severity of this disease, and the fact that it can be spread by aerosol dispersal, the development of effective new antibiotics remains a high priority. As a resource for developing microbial antibiotics, we have focused our efforts on marine microorganisms, particularly those that are in the deep oceans. Examination of a Streptomyces species (our strain CNH365), isolated from near-shore marine sediments found near Santa Barbara, CA, showed that culture extracts possessed significant activity against B. anthracis and methicillin-resistant Staphylococcus aureus in broth dilution assays. Subsequent fractionation of the extract following antibacterial activities yielded a pure

99 citations

Journal ArticleDOI
TL;DR: This animal model of B. anthracis infection reveals that a fatal outcome is dominated by the host septic response, thereby providing important insights into approaches for treatment and prevention of anthrax in humans.
Abstract: Studies that define natural responses to bacterial sepsis assumed new relevance after the lethal bioterrorist attacks with Bacillus anthracis (anthrax), a spore-forming, toxigenic gram-positive bacillus. Considerable effort has focused on identifying adjunctive therapeutics and vaccines to prevent future deaths, but translation of promising compounds into the clinical setting necessitates an animal model that recapitulates responses observed in humans. Here we describe a nonhuman primate (Papio c. cynocephalus) model of B. anthracis infection using infusion of toxigenic B. anthracis Sterne 34F2 bacteria (5 × 105 to 6.5 × 109 CFU/kg). Similar to that seen in human patients, we observed changes in vascular permeability, disseminated intravascular coagulation, and systemic inflammation. The lung was a primary target organ with serosanguinous pleural effusions, intra-alveolar edema, and hemorrhagic lesions. This animal model reveals that a fatal outcome is dominated by the host septic response, thereby providing important insights into approaches for treatment and prevention of anthrax in humans.

99 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
202381
2022169
202181
2020116
2019106