Topic
Bacillus anthracis
About: Bacillus anthracis is a research topic. Over the lifetime, 3994 publications have been published within this topic receiving 128122 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: Time-lapse confocal microscopy is used to follow individual fluorescent spores over time and it is determined that some phagocytized spores survive beyond germination, to become bacilli that then replicate within the macrophages.
Abstract: Macrophages attempt to battle infection with Bacillus anthracis spores by phagocytosis of the spores. However, it is believed that B. anthracis spores may survive phagocytosis and may actually use the macrophages that ingest them as a means of transport to lymph nodes. Thus far, the events that occur after spores undergo phagocytosis have remained unclear. To elucidate the fate of spores internalized by macrophages, we have used time-lapse confocal microscopy to follow individual fluorescent spores over time. By use of this method, we have determined that some phagocytized spores survive beyond germination, to become bacilli that then replicate within the macrophages.
95 citations
TL;DR: It is suggested that BclA acts as a shield to not only reduce the ease with which spores germinate but also change the surface properties of the spore, which, in turn, may impede the interaction with host matrix substances.
Abstract: Bacillus collagen-like protein of anthracis (BclA) is the immunodominant glycoprotein on the exosporium of Bacillus anthracis spores. Here, we sought to assess the impact of BclA on spore germination in vitro and in vivo, surface charge, and interaction with host matrix proteins. For that purpose, we constructed a markerless bclA null mutant in B. anthracis Sterne strain 34F2. The growth and sporulation rates of the ΔbclA and parent strains were nearly indistinguishable, but germination of mutant spores occurred more rapidly than that of wild-type spores in vitro and was more complete by 60 min. Additionally, the mean time to death of A/J mice inoculated subcutaneously or intranasally with mutant spores was lower than that for the wild-type spores even though the 50% lethal doses of the two strains were similar. We speculated that these in vitro and in vivo differences between mutant and wild-type spores might reflect the ease of access of germinants to their receptors in the absence of BclA. We also compared the hydrophobic and adhesive properties of ΔbclA and wild-type spores. The ΔbclA spores were markedly less water repellent than wild-type spores, and, probably as a consequence, the extracellular matrix proteins laminin and fibronectin bound significantly better to mutant than to wild-type spores. These studies suggest that BclA acts as a shield to not only reduce the ease with which spores germinate but also change the surface properties of the spore, which, in turn, may impede the interaction of the spore with host matrix substances.
95 citations
TL;DR: ESI-FTICR-MS improves on the traditional approaches because it does not require fluorescent labeling of PCR products, minimizes post-PCR processing, obviates electrophoresis, and provides unambiguous base composition of both SNP and VNTR PCR products.
Abstract: Epidemiological and forensic analyses of bioterrorism events involving Bacillus anthracis could be improved if both variable number tandem repeats (VNTRs) and single nucleotide polymorphisms (SNPs)...
95 citations
TL;DR: The results indicate that the universal labeling technology based on europium nanoparticles and its application may provide a rapid and sensitive testing platform for clinical diagnosis and laboratory research.
Abstract: We developed a europium nanoparticle-based immunoassay (ENIA) for the sensitive detection of anthrax protective antigen (PA). The ENIA exhibited a linear dose-dependent pattern within the detection range of 0.01 to 100 ng/ml and was approximately 100-fold more sensitive than enzyme-linked immunosorbent assay (ELISA). False-positive results were not observed with serum samples from healthy adults, mouse plasma without PA, or plasma samples collected from mice injected with anthrax lethal factor or edema factor alone. For the detection of plasma samples spiked with PA, the detection sensitivities for ENIA and ELISA were 100% (11/11 samples) and 36.4% (4/11 samples), respectively. The assay exhibited a linear but qualitative correlation between the PA injected and the PA detected in murine blood (r = 0.97731; P < 0.0001). Anthrax PA was also detected in the circulation of mice infected with spores from a toxigenic Sterne-like strain of Bacillus anthracis, but only in the later stages of infection. These results indicate that the universal labeling technology based on europium nanoparticles and its application may provide a rapid and sensitive testing platform for clinical diagnosis and laboratory research.
95 citations
TL;DR: It is shown that CapD, a γ-polyglutamic acid depolymerase encoded on the B. anthracis capsule plasmid, degraded purified capsule and removed the capsule from the surface of anthrax bacilli.
Abstract: The poly-γ-d-glutamic acid capsule confers antiphagocytic properties on Bacillus anthracis and is essential for virulence. In this study, we showed that CapD, a γ-polyglutamic acid depolymerase encoded on the B. anthracis capsule plasmid, degraded purified capsule and removed the capsule from the surface of anthrax bacilli. Treatment with CapD induced macrophage phagocytosis of encapsulated B. anthracis and enabled human neutrophils to kill encapsulated organisms. A second glutamylase, PghP, a γ-polyglutamic acid hydrolase encoded by Bacillus subtilis bacteriophage ΦNIT1, had minimal activity in degrading B. anthracis capsule, no effect on macrophage phagocytosis, and only minimal enhancement of neutrophil killing. Thus, the levels of both phagocytosis and killing corresponded to the degree of enzyme-mediated capsule degradation. The use of enzymes to degrade the capsule and enable phagocytic killing of B. anthracis offers a new approach to the therapy of anthrax.
95 citations