Bacillus anthracis

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

Human Monoclonal Antibody AVP-21D9 to Protective Antigen Reduces Dissemination of the Bacillus anthracis Ames Strain from the Lungs in a Rabbit Model

Abstract: Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some naive animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax.

Synthetic peptidoglycan motifs for germination of bacterial spores.

Abstract: Certain Gram-positive bacteria—as exemplified by Bacillus anthracis, the causative agent of anthrax—can produce dormant and environmentally resistant spores under conditions of nutritional limitation. These spores exit from dormancy via the process of germination that is triggered by exposure to specific molecules.[1] While the precise chemical nature of these molecules, known as germinants, varies according to the organism, they are typically nutrients.[2] Recently, we reported that supernatants from cultures of growing bacteria and constituents of the cell wall could serve as germinants of dormant B. subtilis and B. anthracis spores.[3] Since fragments of the cell wall are released in the course of bacterial growth, the presence of these molecules in the milieu as germination signals might be physiologically relevant.

Production and purification of recombinant protective antigen and protective efficacy against Bacillus anthracis.

Abstract: Recombinant protective antigen (rPA), expressed by Bacillus subtilis WB600 (pPA101), has been purified to homogeneity and the protective efficacy against a Bacillus anthracis challenge has been investigated. rPA was fractionated from culture supernatant fluid by ammonium sulphate, followed by anion exchange chromatography using DEAE Streamline™, anion-exchange chromatography on FPLC MonoQ HR 10/10 and finally, gel filtration chromatography on FPLC Superose 12 HR 10/30, to yield 7 mg rPA per litre of culture. The protective efficacy of rPA against an airborne challenge with the AMES strain of B. anthracis was determined in the presence of the adjuvants, alhydrogel and Ribi, and compared to that achieved by the current UK human vaccine in guinea pigs. rPA combined with the Ribi adjuvant was found to provide 100% protection against challenge.

Reliable detection of Bacillus anthracis , Francisella tularensis and Yersinia pestis by using multiplex qPCR including internal controls for nucleic acid extraction and amplification

Abstract: Background Several pathogens could seriously affect public health if not recognized timely. To reduce the impact of such highly pathogenic micro-organisms, rapid and accurate diagnostic tools are needed for their detection in various samples, including environmental samples.

Inactivation of Bacillus Spores by Ultraviolet or Gamma Radiation

Abstract: Bacillus anthracis spores represent an important bioterrorism agent that can be dispersed in air or water. Existing decontamination practices based on these spores have focused on chemical disinfectants; however, the basic characteristics of radiation-based disinfectants suggest potential advantages in their application for control of Bacillus spores. Experiments were conducted to examine the effectiveness of ultraviolet ( UV254 ) radiation and γ radiation for inactivation of Bacillus spores. Spores of Bacillus cereus were used for most experiments because of their similarity to B. anthracis. A limited number of experiments were also conducted using B. anthracis Sterne spores. In aqueous suspension, B. anthracis Sterne spores were observed to be slightly more resistant to UV254 than the spores of B. cereus. For the conditions of culture and assay used in these experiments, both spore types were more sensitive to UV254 radiation in aqueous suspension than the spores of B. subtilis, which are commonly used ...