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1

Radiolabeled Antibodies to Bacillus anthracis Toxins Are Bactericidal and Partially Therapeutic in Experimental Murine Anthrax?  

PubMed Central

Bacillus anthracis is a powerful agent for use in biological warfare, and infection with the organism is associated with a high rate of mortality, underscoring the need for additional effective therapies for anthrax. Radioimmunotherapy (RIT) takes advantage of the specificity and affinity of the antigen-antibody interaction to deliver a microbicidal radioactive nuclide to a site of infection. RIT has proven therapeutic in experimental models of viral, bacterial, and fungal infections; but it is not known whether this approach can successfully employ toxin binding monoclonal antibodies (MAbs) for diseases caused by toxigenic bacteria. Indirect immunofluorescence studies with MAbs to protective antigen (MAbs 7.5G ?2b and 10F4 ?1) and lethal factor (MAb 14FA ?2b) revealed the surface expression of toxins on bacterial cells. Scatchard analysis of MAbs revealed high binding constants and numerous binding sites on the bacterial surface. To investigate the microbicidal properties of these MAbs, our group radiolabeled MAbs with either 188Re or 213Bi. In vitro, 213Bi was more efficient than 188Re in mediating microbicidal activity against B. anthracis. The administration of MAbs [213Bi]10F4 ?1 and [213Bi]14FA ?2b prolonged the survival of A/JCr mice infected with B. anthracis Sterne bacterial cells but not B. anthracis Sterne spores. These results indicate that RIT with MAbs that target B. anthracis toxin components can be used to treat experimental anthrax infection and suggest that toxigenic bacteria may be targeted with radiolabeled MAbs. PMID:19704133

Rivera, Johanna; Nakouzi, Antonio S.; Morgenstern, Alfred; Bruchertseifer, Frank; Dadachova, Ekaterina; Casadevall, Arturo

2009-01-01

2

Requirements for anthrax toxin entry into cells  

E-print Network

Anthrax lethal toxin-mediated killing of human and murine dendritic cells impairs the adaptive immune response.response to nutrient deprivation and is considered a bacterial survival mechanism. Anthrax

Ryan, Patricia Lynn

2010-01-01

3

Anthrax lethal and edema toxins in anthrax pathogenesis.  

PubMed

The pathophysiological effects resulting from many bacterial diseases are caused by exotoxins released by the bacteria. Bacillus anthracis, a spore-forming bacterium, is such a pathogen, causing anthrax through a combination of bacterial infection and toxemia. B. anthracis causes natural infection in humans and animals and has been a top bioterrorism concern since the 2001 anthrax attacks in the USA. The exotoxins secreted by B. anthracis use capillary morphogenesis protein 2 (CMG2) as the major toxin receptor and play essential roles in pathogenesis during the entire course of the disease. This review focuses on the activities of anthrax toxins and their roles in initial and late stages of anthrax infection. PMID:24684968

Liu, Shihui; Moayeri, Mahtab; Leppla, Stephen H

2014-06-01

4

Anthrax Toxin Receptor 2–Dependent Lethal Toxin Killing In Vivo  

Microsoft Academic Search

Anthrax toxin receptors 1 and 2 (ANTXR1 and ANTXR2) have a related integrin-like inserted (I) domain which interacts with a metal cation that is coordinated by residue D683 of the protective antigen (PA) subunit of anthrax toxin. The receptor-bound metal ion and PA residue D683 are critical for ANTXR1-PA binding. Since PA can bind to ANTXR2 with reduced affinity in

Heather M. Scobie; Darran J. Wigelsworth; John M. Marlett; Diane Thomas; G. Jonah A. Rainey; D. Borden Lacy; Marianne Manchester; R. John Collier; John A. T. Young

2006-01-01

5

Anthrax toxin-induced rupture of artificial lipid bilayer membranes  

PubMed Central

We demonstrate experimentally that anthrax toxin complexes rupture artificial lipid bilayer membranes when isolated from the blood of infected animals. When the solution pH is temporally acidified to mimic that process in endosomes, recombinant anthrax toxin forms an irreversibly bound complex, which also destabilizes membranes. The results suggest an alternative mechanism for the translocation of anthrax toxin into the cytoplasm. PMID:23947891

Nablo, Brian J.; Panchal, Rekha G.; Bavari, Sina; Nguyen, Tam L.; Gussio, Rick; Ribot, Wil; Friedlander, Art; Chabot, Donald; Reiner, Joseph E.; Robertson, Joseph W. F.; Balijepalli, Arvind; Halverson, Kelly M.; Kasianowicz, John J.

2013-01-01

6

Cellular and Systemic Effects of Anthrax Lethal Toxin and Edema Toxin  

PubMed Central

Anthrax lethal toxin (LT) and edema toxin (ET) are the major virulence factors of anthrax and can replicate the lethality and symptoms associated with the disease. This review provides an overview of our current understanding of anthrax toxin effects in animal models and the cytotoxicity (necrosis and apoptosis) induced by LT in different cells. A brief reexamination of early historic findings on toxin in vivo effects in the context of our current knowledge is also presented. PMID:19638283

Moayeri, Mahtab; Leppla, Stephen H.

2009-01-01

7

Rat survival to anthrax lethal toxin is likely controlled by a single gene  

Microsoft Academic Search

We examined whether survival of different rat strains administered anthrax lethal toxin is genetically determined. A reproducible test population of first filial generation hybrid rats was bred based on the susceptibility of progenitors to anthrax lethal toxin and to maximize genetic diversity across the strains. These rats were then tested with varying doses of anthrax lethal toxin. We found that

S H Nye; A L Wittenburg; D L Evans; J A O'Connor; R J Roman; H J Jacob

2008-01-01

8

Polyvalent Recognition of Biopolymers:The Design of Potent Inhibitors of Anthrax Toxin  

Microsoft Academic Search

Polyvalency -- the simultaneous binding of multiple ligands on one entity to multiple receptors on another -- is a phenomenon that is ubiquitous in nature. We are using a biomimetic approach, inspired by polyvalency, to design potent inhibitors of anthrax toxin. Since the major symptoms and death from anthrax are due primarily to the action of anthrax toxin, the toxin

Ravi Kane

2007-01-01

9

Polyvalent inhibitors of anthrax toxin that target host receptors  

PubMed Central

Resistance of pathogens to antimicrobial therapeutics has become a widespread problem. Resistance can emerge naturally, but it can also be engineered intentionally, which is an important consideration in designing therapeutics for bioterrorism agents. Blocking host receptors used by pathogens represents a powerful strategy to overcome this problem, because extensive alterations to the pathogen may be required to enable it to switch to a new receptor that can still support pathogenesis. Here, we demonstrate a facile method for producing potent receptor-directed antitoxins. We used phage display to identify a peptide that binds both anthrax-toxin receptors and attached this peptide to a synthetic scaffold. Polyvalency increased the potency of these peptides by >50,000-fold in vitro and enabled the neutralization of anthrax toxin in vivo. This work demonstrates a receptor-directed anthrax-toxin inhibitor and represents a promising strategy to combat a variety of viral and bacterial diseases. PMID:16938891

Basha, Saleem; Rai, Prakash; Poon, Vincent; Saraph, Arundhati; Gujraty, Kunal; Go, Mandy Y.; Sadacharan, Skanda; Frost, Mia; Mogridge, Jeremy; Kane, Ravi S.

2006-01-01

10

Structure-based Design of a Heptavalent Anthrax Toxin Inhibitor  

PubMed Central

The design of polyvalent molecules, consisting of multiple copies of a biospecific ligand attached to a suitable scaffold, represents a promising approach to inhibit pathogens and oligomeric microbial toxins. Despite the increasing interest in structure-based drug design, few polyvalent inhibitors based on this approach have shown efficacy in vivo. Here we demonstrate the structure-based design of potent biospecific heptavalent inhibitors of anthrax lethal toxin. Specifically, we illustrate the ability to design potent polyvalent ligands by matching the pattern of binding sites on the biological target. We used a combination of experimental studies based on mutagenesis and computational docking studies to identify the binding site for an inhibitory peptide on the heptameric subunit of anthrax toxin. We developed an approach based on copper-catalyzed azide-alkyne cycloaddition (click-chemistry) to facilitate the attachment of seven copies of the inhibitory peptide to a ?-cyclodextrin core via a polyethylene glycol linker of an appropriate length. The resulting heptavalent inhibitors neutralized anthrax lethal toxin both in vitro and in vivo and showed appreciable stability in serum. Given the inherent biocompatibility of cyclodextrin and polyethylene glycol, these potent well-defined heptavalent inhibitors show considerable promise as anthrax anti-toxins. PMID:21302959

Joshi, Amit; Kate, Sandesh; Poon, Vincent; Mondal, Dhananjoy; Boggara, Mohan B.; Saraph, Arundhati; Martin, Jacob T.; McAlpine, Ryan; Day, Ryan; Garcia, Angel E.; Mogridge, Jeremy; Kane, Ravi S.

2011-01-01

11

Identification of the cellular receptor for anthrax toxin  

NASA Astrophysics Data System (ADS)

The tripartite toxin secreted by Bacillus anthracis, the causative agent of anthrax, helps the bacterium evade the immune system and can kill the host during a systemic infection. Two components of the toxin enzymatically modify substrates within the cytosol of mammalian cells: oedema factor (OF) is an adenylate cyclase that impairs host defences through a variety of mechanisms including inhibiting phagocytosis; lethal factor (LF) is a zinc-dependent protease that cleaves mitogen-activated protein kinase kinase and causes lysis of macrophages. Protective antigen (PA), the third component, binds to a cellular receptor and mediates delivery of the enzymatic components to the cytosol. Here we describe the cloning of the human PA receptor using a genetic complementation approach. The receptor, termed ATR (anthrax toxin receptor), is a type I membrane protein with an extracellular von Willebrand factor A domain that binds directly to PA. In addition, a soluble version of this domain can protect cells from the action of the toxin.

Bradley, Kenneth A.; Mogridge, Jeremy; Mourez, Michael; Collier, R. John; Young, John A. T.

2001-11-01

12

New insights into the biological effects of anthrax toxins: linking cellular to organismal responses  

E-print Network

Review New insights into the biological effects of anthrax toxins: linking cellular to organismal responses Annabel Guichard a , Victor Nizet b,c , Ethan Bier a,* a Section of Cell and Developmental Biology The anthrax toxins lethal toxin (LT) and edema toxin (ET) are essential virulence factors produced by Bacillus

Nizet, Victor

13

Pathophysiological Manifestations in Mice Exposed to Anthrax Lethal Toxin  

PubMed Central

Pathophysiological changes associated with anthrax lethal toxin included loss of plasma proteins, decreased platelet count, slower clotting times, fibrin deposits in tissue sections, and gross and histopathological evidence of hemorrhage. These findings suggest that blood vessel leakage and hemorrhage lead to disseminating intravascular coagulation and/or circulatory shock as an underlying pathophysiological mechanism. PMID:16177381

Culley, Nathan C.; Pinson, David M.; Chakrabarty, Anuradha; Mayo, Matthew S.; LeVine, Steven M.

2005-01-01

14

Early response in macrophages by exposure to a low concentration of anthrax lethal toxin  

Microsoft Academic Search

The central role in the pathogenesis of anthrax is played by the two classical anthrax toxins. Three factors that are secreted\\u000a by the bacterium combine to form two bipartite toxins. Edema toxin, consisting of the protective antigen (PA) and the edema\\u000a factor (EF), causes the edema associated with anthrax infection. Lethal toxin (LeTx), composed of PA and the lethal factor

Kyoung Hwa Jung; JeongAh Nam; Ji Cheon Kim; Seoung Joo Kim; Kwang Gun Oh; Sang Hoon Kim; Young Gyu Chai

2011-01-01

15

Crystallographic studies of the Anthrax lethal toxin. Annual report  

SciTech Connect

The lethal form of Anthrax results from the inhalation of anthrax spores. Death is primarily due to the effects of the lethal toxin (Protective Antigen (PA) + Lethal Factor) from the causative agent, Bacillus anthracis. All the Anthrax vaccines currently in use or under development contain or produce PA, the major antigenic component of anthrax toxin, and there is a clear need for an improved vaccine for human use. In the previous report we described the first atomic resolution structure of PA, revealing that the molecule is composed largely of beta-sheets organized into four domains. This information can be used in the design. of recombinant PA vaccines. In this report we describe additional features of the full-length PA molecule derived from further crystallographic refinement and careful examination of the structure. We compare two crystal forms of PA grown at different pH values and discuss the functional implications. A complete definition of the function of each domain must await the crystal structure of the PA63 heptamer. We have grown crystals of the heptamer under both detergent and detergent-free conditions, and made substantial progress towards the crystal structure. The mechanism of anthrax intoxication in the light of our results is reviewed.

Frederick, C.A.

1996-07-01

16

The role of antibodies to Bacillus anthracis and anthrax toxin components in inhibiting the early stages of infection by anthrax spores  

Microsoft Academic Search

Vaccines which are efficacious against anthrax, such as the human vaccine, Anthrax Vaccine Absorbed (AVA), contain the protective antigen (PA) component of the anthrax toxins as the major protective immunogen. Although AVA protects against inhalational anthrax, the immune responses to and role in protection of PA and possibly other antigens have yet to be fully elucidated. Sera from animals immunized

Susan Welkos; Stephen Little; Arthur Friedlander; David Fritz; Patricia Fellows

17

Polyvalent Recognition of Biopolymers:The Design of Potent Inhibitors of Anthrax Toxin  

NASA Astrophysics Data System (ADS)

Polyvalency -- the simultaneous binding of multiple ligands on one entity to multiple receptors on another -- is a phenomenon that is ubiquitous in nature. We are using a biomimetic approach, inspired by polyvalency, to design potent inhibitors of anthrax toxin. Since the major symptoms and death from anthrax are due primarily to the action of anthrax toxin, the toxin is a prime target for therapeutic intervention. We describe the design of potent polyvalent anthrax toxin inhibitors, and will discuss the role of pattern matching in polyvalent recognition. Pattern-matched polyvalent inhibitors can neutralize anthrax toxin in vivo, and may enable the successful treatment of anthrax during the later stages of the disease, when antibiotic treatment is ineffective.

Kane, Ravi

2007-03-01

18

Induction Of Histamine, Bradykinin And Serotonin Release In Response To Anthrax Lethal Toxin  

Microsoft Academic Search

Background: Anthrax lethal toxin (LeTx) is a major virulence factor in anthrax infection but compelling evidence suggests that it exerts a strong inhibitory effect on macrophage cytokine production. This leaves no definitive explanation as to the etiology of many of the early signs and symptoms, seen in inhalational anthrax infection. Methods: The responses of histamine, bradykinin and serotonin release to

Yue Lydia Li; Darya Alibek; Raymond S. Weinstein; Joseph Shiloach; Qingzhu Zhai; Dustin Schaffner; Kenneth Alibek; Aiguo Wu

2009-01-01

19

Standardized, mathematical model-based and validated in vitro analysis of anthrax lethal toxin neutralization  

Microsoft Academic Search

Quantification of anthrax lethal toxin (LTx) neutralization activity (TNA) is pivotal in assessing protective antibody responses to anthrax vaccines and for evaluation of immunotherapies for anthrax. We have adapted and redesigned the TNA assay to establish a unifying, standardized, quantitative and validated technology platform for LTx neutralization in the J774A.1 murine cell line. Critical design features of this platform are

Han Li; Stephen D. Soroka; Thomas H. Taylor Jr.; Karen L. Stamey; Kelly Wallace Stinson; Alison E. Freeman; Darbi R. Abramson; Rita Desai; Li X. Cronin; J. Wade Oxford; Joseph Caba; Cynthia Pleatman; Sonal Pathak; Daniel S. Schmidt; Vera A. Semenova; Sandra K. Martin; Patricia P. Wilkins; Conrad P. Quinn

2008-01-01

20

Genetically modified anthrax lethal toxin safely delivers whole HIV protein antigens into the  

E-print Network

Genetically modified anthrax lethal toxin safely delivers whole HIV protein antigens, 2000 (received for review January 24, 2000) Bacillus anthrax lethal toxin can be engineered to deliver cytotoxic T lymphocyte response in HIV-infected donor peripheral blood mononuclear cells in vitro

Lieberman, Judy

21

Nasal immunization with a dual antigen anthrax vaccine induced strong mucosal and systemic immune responses against toxins and bacilli  

Microsoft Academic Search

Anthrax-vaccine-adsorbed (AVA), the only anthrax vaccine licensed in the U.S., suffers from many major drawbacks. Therefore, there is a need to develop new generation anthrax vaccines that can be easily administered and induce strong immune responses not only against the anthrax toxins, but also against the toxin-producing vegetative anthrax bacilli. In the present study, we evaluated the feasibility of inducing

Brian R. Sloat; Zhengrong Cui

2006-01-01

22

Synthesis of Potent Inhibitors of Anthrax Toxin Based on Poly-L-Glutamic Acid  

PubMed Central

We report the synthesis of biodegradable polyvalent inhibitors of anthrax toxin based on poly-L-glutamic acid (PLGA). These biocompatible polyvalent inhibitors are at least four orders of magnitude more potent than the corresponding monovalent peptides in vitro and are comparable in potency to polyacrylamide-based inhibitors of anthrax toxin assembly. We have elucidated the influence of peptide density on inhibitory potency and demonstrate that these inhibitory potencies are limited by kinetics, with even higher activities seen when the inhibitors are preincubated with the heptameric receptor-binding subunit of anthrax toxin prior to exposure to cells. These polyvalent inhibitors are also effective at neutralizing anthrax toxin in vivo and represent attractive leads for designing biocompatible anthrax therapeutics. PMID:16984137

Joshi, Amit; Saraph, Arundhati; Poon, Vincent; Mogridge, Jeremy; Kane, Ravi S.

2008-01-01

23

Effect of nasal immunization with protective antigen of Bacillus anthracis on protective immune response against anthrax toxin  

Microsoft Academic Search

Anthrax toxin consists of three proteins: protective antigen (PA), lethal factor (LF) and edema factor (EF). PA in combination with LF (lethal toxin) is lethal to mammalian cells and is the major component of human anthrax vaccine. Immunization with PA elicits the production of neutralizing antibodies that form a major component of the protective immunity against anthrax. Recent reports have

Reetika Gaur; Pradeep K. Gupta; Akhil C. Banerjea; Yogendra Singh

2002-01-01

24

Proteasomes Control Caspase-1 Activation in Anthrax Lethal Toxin-mediated Cell Killing*S  

E-print Network

Proteasomes Control Caspase-1 Activation in Anthrax Lethal Toxin-mediated Cell Killing*S Received York 10461 Activation of caspase-1 through the inflammasome protein Nalp1b controls anthrax lethal evidence of membrane impairment recovered upon the addition of MG132, mirroring the Boc-D-cmk response

Brojatsch, Jürgen

25

Anthrax Toxin Induces Macrophage Death by p38 MAPK Inhibition but Leads to  

E-print Network

Immunity Article Anthrax Toxin Induces Macrophage Death by p38 MAPK Inhibition but Leads of innate immunity, leading to activation of protective host responses. However, it is still unclear how of the Gram-positive bacterial pathogen Bacillus anthracis, the causative agent of anthrax (Tournier et al

Nizet, Victor

26

Suppressive Effects of Anthrax Lethal Toxin on Megakaryopoiesis  

PubMed Central

Anthrax lethal toxin (LT) is a major virulence factor of Bacillus anthracis. LT challenge suppresses platelet counts and platelet function in mice, however, the mechanism responsible for thrombocytopenia remains unclear. LT inhibits cellular mitogen-activated protein kinases (MAPKs), which are vital pathways responsible for cell survival, differentiation, and maturation. One of the MAPKs, the MEK1/2-extracellular signal-regulated kinase pathway, is particularly important in megakaryopoiesis. This study evaluates the hypothesis that LT may suppress the progenitor cells of platelets, thereby inducing thrombocytopenic responses. Using cord blood-derived CD34+ cells and mouse bone marrow mononuclear cells to perform in vitro differentiation, this work shows that LT suppresses megakaryopoiesis by reducing the survival of megakaryocytes. Thrombopoietin treatments can reduce thrombocytopenia, megakaryocytic suppression, and the quick onset of lethality in LT-challenged mice. These results suggest that megakaryocytic suppression is one of the mechanisms by which LT induces thrombocytopenia. These findings may provide new insights for developing feasible approaches against anthrax. PMID:23555687

Lin, Guan-Ling; Wang, Tsung-Pao; Lai, Yi-Ling; Lin, Ting-Kai; Hsieh, Ming-Chun; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Hsu, Hui-Ling; Liao, Chi-Yuan; Sun, Der-Shan

2013-01-01

27

Suppressive effects of anthrax lethal toxin on megakaryopoiesis.  

PubMed

Anthrax lethal toxin (LT) is a major virulence factor of Bacillus anthracis. LT challenge suppresses platelet counts and platelet function in mice, however, the mechanism responsible for thrombocytopenia remains unclear. LT inhibits cellular mitogen-activated protein kinases (MAPKs), which are vital pathways responsible for cell survival, differentiation, and maturation. One of the MAPKs, the MEK1/2-extracellular signal-regulated kinase pathway, is particularly important in megakaryopoiesis. This study evaluates the hypothesis that LT may suppress the progenitor cells of platelets, thereby inducing thrombocytopenic responses. Using cord blood-derived CD34(+) cells and mouse bone marrow mononuclear cells to perform in vitro differentiation, this work shows that LT suppresses megakaryopoiesis by reducing the survival of megakaryocytes. Thrombopoietin treatments can reduce thrombocytopenia, megakaryocytic suppression, and the quick onset of lethality in LT-challenged mice. These results suggest that megakaryocytic suppression is one of the mechanisms by which LT induces thrombocytopenia. These findings may provide new insights for developing feasible approaches against anthrax. PMID:23555687

Chen, Po-Kong; Chang, Hsin-Hou; Lin, Guan-Ling; Wang, Tsung-Pao; Lai, Yi-Ling; Lin, Ting-Kai; Hsieh, Ming-Chun; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Hsu, Hui-Ling; Liao, Chi-Yuan; Sun, Der-Shan

2013-01-01

28

Anthrax vaccine design: strategies to achieve comprehensive protection against spore, bacillus, and toxin  

PubMed Central

The successful use of Bacillus anthracis as a lethal biological weapon has prompted renewed research interest in the development of more effective vaccines against anthrax. The disease consists of three critical components: spore, bacillus, and toxin, elimination of any of which confers at least partial protection against anthrax. Current remedies rely on postexposure antibiotics to eliminate bacilli and pre- and postexposure vaccination to target primarily toxins. Vaccines effective against toxin have been licensed for human use, but need improvement. Vaccines against bacilli have recently been developed by us and others. Whether effective vaccines will be developed against spores is still an open question. An ideal vaccine would confer simultaneous protection against spores, bacilli, and toxins. One step towards this goal is our dually active vaccine, designed to destroy both bacilli and toxin. Existing and potential strategies towards potent and effective anthrax vaccines are discussed in this review. PMID:15790405

Wang, Julia Y; Roehrl, Michael H

2005-01-01

29

New insights into the biological effects of anthrax toxins: linking cellular to organismal responses  

PubMed Central

The anthrax toxins lethal toxin (LT) and edema toxin (ET), are essential virulence factors produced by B. anthracis. These toxins act during two distinct phases of anthrax infection. During the first, prodromal phase, which is often asymptomatic, anthrax toxins act on cells of the immune system to help the pathogen establish infection. Then, during the rapidly progressing (or fulminant) stage of the disease bacteria disseminate via a hematological route to various target tissues and organs, which are typically highly vascularized. As bacteria proliferate in the bloodstream LT and ET begin to accumulate rapidly reaching a critical threshold level that will cause death even when the bacterial proliferation is curtailed by antibiotics. During this final phase of infection the toxins cause an increase in vascular permeability and a decrease in function of target organs including the heart, spleen, kidney, adrenal gland, and brain. In this review, we examine the various biological effects of anthrax toxins, focusing on the fulminant stage of the disease and on mechanisms by which the two toxins may collaborate to cause cardiovascular collapse. We discuss normal mechanisms involved in maintaining vascular integrity and based on recent studies indicating that LT and ET cooperatively inhibit membrane trafficking to cell-cell junctions we explore several potential mechanisms by which the toxins may achieve their lethal effects. We also summarize the effects of other potential virulence factors secreted by B. anthracis and consider the role of toxic factors in the evolutionarily recent emergence of this devastating disease. PMID:21930233

Guichard, Annabel; Nizet, Victor; Bier, Ethan

2013-01-01

30

Inhibition of Anthrax Lethal Toxin-Induced Cytolysis of RAW264.7 Cells by Celastrol  

Microsoft Academic Search

BackgroundBacillus anthracis is the bacterium responsible for causing anthrax. The ability of B. anthracis to cause disease is dependent on a secreted virulence factor, lethal toxin, that promotes survival of the bacteria in the host by impairing the immune response. A well-studied effect of lethal toxin is the killing of macrophages, although the molecular mechanisms involved have not been fully

Sarah Chapelsky; Sarah Batty; Mia Frost; Jeremy Mogridge; Ping Wang

2008-01-01

31

Involvement of Domain 3 in Oligomerization by the Protective Antigen Moiety of Anthrax Toxin  

Microsoft Academic Search

Protective antigen (PA), a component of anthrax toxin, binds receptors on mammalian cells and is activated by a cell surface protease. The resulting active fragment, PA63, forms ring-shaped heptamers, binds the en- zymic moieties of the toxin, and translocates them to the cytosol. Of the four crystallographic domains of PA, domain 1 has been implicated in binding the enzymic moieties;

JEREMY MOGRIDGE; MICHAEL MOUREZ; R. JOHN COLLIER

2001-01-01

32

New Developments in Vaccines, Inhibitors of Anthrax Toxins, and Antibiotic Therapeutics for Bacillus anthracis  

PubMed Central

Bacillus anthracis, the causative agent responsible for anthrax infections, poses a significant biodefense threat. There is a high mortality rate associated with untreated anthrax infections; specifically, inhalation anthrax is a particularly virulent form of infection with mortality rates close to 100%, even with aggressive treatment. Currently, a vaccine is not available to the general public and few antibiotics have been approved by the FDA for the treatment of inhalation anthrax. With the threat of natural or engineered bacterial resistance to antibiotics and the limited population for whom the current drugs are approved, there is a clear need for more effective treatments against this deadly infection. A comprehensive review of current research in drug discovery is presented in this article, including efforts to improve the purity and stability of vaccines, design inhibitors targeting the anthrax toxins, and identify inhibitors of novel enzyme targets. High resolution structural information for the anthrax toxins and several essential metabolic enzymes has played a significant role in aiding the structure-based design of potent and selective antibiotics. PMID:22050756

Beierlein, J.M.; Anderson, A.C.

2013-01-01

33

Delayed Toxicity Associated with Soluble Anthrax Toxin Receptor Decoy-Ig Fusion Protein Treatment  

PubMed Central

Soluble receptor decoy inhibitors, including receptor-immunogloubulin (Ig) fusion proteins, have shown promise as candidate anthrax toxin therapeutics. These agents act by binding to the receptor-interaction site on the protective antigen (PA) toxin subunit, thereby blocking toxin binding to cell surface receptors. Here we have made the surprising observation that co-administration of receptor decoy-Ig fusion proteins significantly delayed, but did not protect, rats challenged with anthrax lethal toxin. The delayed toxicity was associated with the in vivo assembly of a long-lived complex comprised of anthrax lethal toxin and the receptor decoy-Ig inhibitor. Intoxication in this system presumably results from the slow dissociation of the toxin complex from the inhibitor following their prolonged circulation. We conclude that while receptor decoy-Ig proteins represent promising candidates for the early treatment of B. anthracis infection, they may not be suitable for therapeutic use at later stages when fatal levels of toxin have already accumulated in the bloodstream. PMID:22511955

Cote, Christopher; Welkos, Susan; Manchester, Marianne; Young, John A. T.

2012-01-01

34

Self-association of the Transmembrane Domain of an Anthrax Toxin Receptor  

Microsoft Academic Search

Protective antigen (PA), lethal factor (LF) and edema factor (EF) are secreted individually by Bacillus anthracis. These components of anthrax toxin must then assemble into complexes to intoxicate mammalian cells. Toxin assembly initiates when molecules of PA bind mammalian receptors ANTXR1\\/2 and are cleaved by surface proteases into 20 kDa and 63 kDa fragments. After PA20 dissociates, receptor-bound PA63 homo-oligomerizes into heptamers.

Mandy Y. Go; Sanguk Kim; Anthony W. Partridge; Roman A. Melnyk; Arianna Rath; Charles M. Deber; Jeremy Mogridge

2006-01-01

35

Anthrax Lethal Toxin-Mediated Killing of Human and Murine Dendritic Cells Impairs  

E-print Network

Anthrax Lethal Toxin-Mediated Killing of Human and Murine Dendritic Cells Impairs the Adaptive Immune Response Abdelkrim Alileche¤ , Evan R. Serfass, Stefan M. Muehlbauer, Steven A. Porcelli, Ju, United States of America Many pathogens have acquired strategies to combat the immune response. Bacillus

Brojatsch, Jürgen

36

The Design of Potent Liposome-Based Inhibitors of Anthrax Toxin  

NASA Astrophysics Data System (ADS)

Several biological processes involve the recognition of a specific pattern of binding sites on a target surface. Theoreticians have predicted that endowing synthetic biomimetic structures with statistical pattern matching capabilities may impact the development of sensors and separation processes. We demonstrated for the first time that statistical pattern matching significantly enhances the potency of a polyvalent therapeutic -- an anthrax toxin inhibitor. We functionalized liposomes with an inhibitory peptide at different densities and observed a transition in potency at an inter-peptide separation that matches the distance between ligand-binding sites on the heptameric subunit of anthrax toxin. Pattern-matched polyvalent liposomes neutralized anthrax toxin in vitro at concentrations four orders of magnitude lower than the corresponding monovalent peptide. We also showed that polyvalent liposome-based inhibitors can neutralize a microbial toxin in vivo. Statistical pattern matching represents a facile strategy to enhance the potency of therapeutics targeting toxins or pathogens. Our results also illuminate other fundamental aspects of polyvalent recognition --specifically we found that the efficiency of polyvalent inhibition is influenced by the competition between the rates of ligand dissociation and diffusion.

Rai, Prakash; Padala, Chakradhar; Poon, Vincent; Saraph, Arundhati; Basha, Saleem; Kate, Sandesh; Tao, Kevin; Mogridge, Jeremy; Kane, Ravi

2006-03-01

37

A Human/Murine Chimeric Fab Antibody Neutralizes Anthrax Lethal Toxin In Vitro  

PubMed Central

Human anthrax infection caused by exposure to Bacillus anthracis cannot always be treated by antibiotics. This is mostly because of the effect of the remaining anthrax toxin in the body. Lethal factor (LF) is a component of lethal toxin (LeTx), which is the major virulence of anthrax toxin. A murine IgG monoclonal antibody (mAb) against LF with blocking activity (coded LF8) was produced in a previous study. In this report, a human/murine chimeric Fab mAb (coded LF8-Fab) was developed from LF8 by inserting murine variable regions into human constant regions using antibody engineering to reduce the incompatibility of the murine antibody for human use. The LF8-Fab expressed in Escherichia coli could specifically identify LF with an affinity of 3.46 × 107?L/mol and could neutralize LeTx with an EC50 of 85??g/mL. Even after LeTx challenge at various time points, the LF8-Fab demonstrated protection of J774A.1 cells in vitro. The results suggest that the LF8-Fab might be further characterized and potentially be used for clinical applications against anthrax infection. PMID:23861692

Chen, Ximin; Zhu, Jin; Duesbery, Nicholas S.; Cheng, Xunjia; Cao, Brian

2013-01-01

38

Anthrax  

MedlinePLUS Videos and Cool Tools

... very rare infectious disease that can spread from animals to humans. The recent use of anthrax by ... Last reviewed: 10/15/2012 1 Warm-blooded animals such as sheep, cattle, horses, goats, and swine ...

39

Protection against anthrax toxin by vaccination with a DNA plasmid encoding anthrax protective antigen  

Microsoft Academic Search

A DNA vaccine encoding the immunogenic and biologically active portion of anthrax protective antigen (PA) was constructed. Spleen cells from BALB\\/c mice immunized intramuscularly with this vaccine were stimulated to secrete IFN? and IL-4 when exposed to PA in vitro. Immunized mice also mounted a humoral immune response dominated by IgG1 anti-PA antibody production, the subclass previously shown to confer

Mi-Li Gu; Stephen H Leppla; Dennis M Klinman

1999-01-01

40

Direct Interaction between Anthrax Toxin Receptor 1 and the Actin Cytoskeleton  

PubMed Central

The protective antigen component of anthrax toxin binds the I domain of the anthrax toxin receptors, ANTXR1 and ANTXR2, in a manner akin to how integrins bind their ligands. The I domains of integrins and ANTXR1 both have high and low affinity conformations and the cytosolic tails of these receptors associate with the actin cytoskeleton. The association of ANTXR1 with the cytoskeleton correlates with diminished binding to PA, although a mechanistic explanation for this observation is lacking. Here, we identified a segment in the cytoplasmic tail of ANTXR1 required for its association with the cytoskeleton. We synthesized a 60-mer peptide based on this segment and demonstrated a direct interaction between the peptide and ?-actin, indicating that in contrast to integrins, ANTXR1 does not use an adaptor to bind the cytoskeleton. This peptide orders actin filaments into arrays, demonstrating an actin-bundling activity that is novel for a membrane protein. PMID:19817382

Garlick, Kristopher M.; Mogridge, Jeremy

2010-01-01

41

Crystallographic studies of the anthrax lethal toxin. Final report, 1 July 1994-31 December 1996  

Microsoft Academic Search

Protective Antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthraces, the organism responsible for anthrax. Following proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that translocates the toxic enzymes into the cytosol. We have solved the crystal structure of monomeric PA at 2.1 A resolution and the water-soluble heptamer at

1997-01-01

42

Anthrax lethal toxin downregulates claudin-5 expression in human endothelial tight junctions.  

PubMed

Vascular leakage pathologies such as pleural effusion and hemorrhage are hallmarks of anthrax pathogenesis. We previously reported that anthrax lethal toxin (LT), the major virulence factor of anthrax, reduces barrier function in cultured primary human microvascular endothelial cells. Here, we show that LT-induced barrier dysfunction is accompanied by the reduced expression of the endothelial tight junction (TJ) protein claudin-5 but no change in the expression of other TJ components occludin, ZO-1, ZO-2, or the adherens junction (AJ) protein VE-cadherin. The downregulation of claudin-5 correlated temporally and dose-dependently with the reduction of transendothelial electrical resistance. LT-induced loss of claudin-5 was independent of cell death and preceded the appearance of actin stress fibers and altered AJ morphology. Pharmacological inhibition of MEK-1/2, two kinases that are proteolytically inactivated by LT, showed a similar reduction in claudin-5 expression. We found that LT reduced claudin-5 mRNA levels but did not accelerate the rate of claudin-5 degradation. Mice challenged with LT also showed significant reduction in claudin-5 expression. Together, these findings support a possible role for LT disruption of endothelial TJs in the vascular leakage pathologies of anthrax. PMID:23626836

D'Agnillo, Felice; Williams, Matthew C; Moayeri, Mahtab; Warfel, Jason M

2013-01-01

43

Anthrax Lethal Toxin Downregulates Claudin-5 Expression in Human Endothelial Tight Junctions  

PubMed Central

Vascular leakage pathologies such as pleural effusion and hemorrhage are hallmarks of anthrax pathogenesis. We previously reported that anthrax lethal toxin (LT), the major virulence factor of anthrax, reduces barrier function in cultured primary human microvascular endothelial cells. Here, we show that LT-induced barrier dysfunction is accompanied by the reduced expression of the endothelial tight junction (TJ) protein claudin-5 but no change in the expression of other TJ components occludin, ZO-1, ZO-2, or the adherens junction (AJ) protein VE-cadherin. The downregulation of claudin-5 correlated temporally and dose-dependently with the reduction of transendothelial electrical resistance. LT-induced loss of claudin-5 was independent of cell death and preceded the appearance of actin stress fibers and altered AJ morphology. Pharmacological inhibition of MEK-1/2, two kinases that are proteolytically inactivated by LT, showed a similar reduction in claudin-5 expression. We found that LT reduced claudin-5 mRNA levels but did not accelerate the rate of claudin-5 degradation. Mice challenged with LT also showed significant reduction in claudin-5 expression. Together, these findings support a possible role for LT disruption of endothelial TJs in the vascular leakage pathologies of anthrax. PMID:23626836

D'Agnillo, Felice; Williams, Matthew C.; Moayeri, Mahtab; Warfel, Jason M.

2013-01-01

44

Erythropoiesis suppression is associated with anthrax lethal toxin-mediated pathogenic progression.  

PubMed

Anthrax is a disease caused by the bacterium Bacillus anthracis, which results in high mortality in animals and humans. Although some of the mechanisms are already known such as asphyxia, extensive knowledge of molecular pathogenesis of this disease is deficient and remains to be further investigated. Lethal toxin (LT) is a major virulence factor of B. anthracis and a specific inhibitor/protease of mitogen-activated protein kinase kinases (MAPKKs). Anthrax LT causes lethality and induces certain anthrax-like symptoms, such as anemia and hypoxia, in experimental mice. Mitogen-activated protein kinases (MAPKs) are the downstream pathways of MAPKKs, and are important for erythropoiesis. This prompted us to hypothesize that anemia and hypoxia may in part be exacerbated by erythropoietic dysfunction. As revealed by colony-forming cell assays in this study, LT challenges significantly reduced mouse erythroid progenitor cells. In addition, in a proteolytic activity-dependent manner, LT suppressed cell survival and differentiation of cord blood CD34(+)-derived erythroblasts in vitro. Suppression of cell numbers and the percentage of erythroblasts in the bone marrow were detected in LT-challenged C57BL/6J mice. In contrast, erythropoiesis was provoked through treatments of erythropoietin, significantly ameliorating the anemia and reducing the mortality of LT-treated mice. These data suggested that suppressed erythropoiesis is part of the pathophysiology of LT-mediated intoxication. Because specific treatments to overcome LT-mediated pathogenesis are still lacking, these efforts may help the development of effective treatments against anthrax. PMID:23977125

Chang, Hsin-Hou; Wang, Tsung-Pao; Chen, Po-Kong; Lin, Yo-Yin; Liao, Chih-Hsien; Lin, Ting-Kai; Chiang, Ya-Wen; Lin, Wen-Bin; Chiang, Chih-Yu; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Hsu, Hui-Ling; Liao, Chi-Yuan; Sun, Der-Shan

2013-01-01

45

Endocrine Perturbation Increases Susceptibility of Mice to Anthrax Lethal Toxin  

Microsoft Academic Search

Bacillus anthracis lethal toxin (LT) causes vascular collapse and high lethality in BALB\\/cJ mice, intermediate lethality in C57BL\\/6J mice, and no lethality in DBA\\/2J mice. We found that adrenalectomized (ADX) mice of all three strains had increased susceptibility to LT. The increased susceptibility of ADX-DBA\\/2J mice was not accompanied by changes in their macrophage sensitivity or cytokine response to LT.

Mahtab Moayeri; Jeanette I. Webster; Jason F. Wiggins; Stephen H. Leppla; Esther M. Sternberg

2005-01-01

46

Crystal structure of a complex between anthrax toxin and its host cell receptor.  

PubMed

Anthrax toxin consists of the proteins protective antigen (PA), lethal factor (LF) and oedema factor (EF). The first step of toxin entry into host cells is the recognition by PA of a receptor on the surface of the target cell. Subsequent cleavage of receptor-bound PA enables EF and LF to bind and form a heptameric PA63 pre-pore, which triggers endocytosis. Upon acidification of the endosome, PA63 forms a pore that inserts into the membrane and translocates EF and LF into the cytosol. Two closely related host cell receptors, TEM8 and CMG2, have been identified. Both bind to PA with high affinity and are capable of mediating toxicity. Here, we report the crystal structure of the PA-CMG2 complex at 2.5 A resolution. The structure reveals an extensive receptor-pathogen interaction surface mimicking the non-pathogenic recognition of the extracellular matrix by integrins. The binding surface is closely conserved in the two receptors and across species, but is quite different in the integrin domains, explaining the specificity of the interaction. CMG2 engages two domains of PA, and modelling of the receptor-bound PA63 heptamer suggests that the receptor acts as a pH-sensitive brace to ensure accurate and timely membrane insertion. The structure provides new leads for the discovery of anthrax anti-toxins, and should aid the design of cancer therapeutics. PMID:15243628

Santelli, Eugenio; Bankston, Laurie A; Leppla, Stephen H; Liddington, Robert C

2004-08-19

47

A Receptor-based Switch that Regulates Anthrax Toxin Pore Formation  

PubMed Central

Cellular receptors can act as molecular switches, regulating the sensitivity of microbial proteins to conformational changes that promote cellular entry. The activities of these receptor-based switches are only partially understood. In this paper, we sought to understand the mechanism that underlies the activity of the ANTXR2 anthrax toxin receptor-based switch that binds to domains 2 and 4 of the protective antigen (PA) toxin subunit. Receptor-binding restricts structural changes within the heptameric PA prepore that are required for pore conversion to an acidic endosomal compartment. The transfer cross-saturation (TCS) NMR approach was used to monitor changes in the heptameric PA-receptor contacts at different steps during prepore-to-pore conversion. These studies demonstrated that receptor contact with PA domain 2 is weakened prior to pore conversion, defining a novel intermediate in this pathway. Importantly, ANTXR2 remained bound to PA domain 4 following pore conversion, suggesting that the bound receptor might influence the structure and/or function of the newly formed pore. These studies provide new insights into the function of a receptor-based molecular switch that controls anthrax toxin entry into cells. PMID:22174672

Pilpa, Rosemarie M.; Bayrhuber, Monika; Marlett, John M.; Riek, Roland; Young, John A. T.

2011-01-01

48

Designed Azolopyridinium Salts Block Protective Antigen Pores In Vitro and Protect Cells from Anthrax Toxin  

PubMed Central

Background Several intracellular acting bacterial protein toxins of the AB-type, which are known to enter cells by endocytosis, are shown to produce channels. This holds true for protective antigen (PA), the binding component of the tripartite anthrax-toxin of Bacillus anthracis. Evidence has been presented that translocation of the enzymatic components of anthrax-toxin across the endosomal membrane of target cells and channel formation by the heptameric/octameric PA63 binding/translocation component are related phenomena. Chloroquine and some 4-aminoquinolones, known as potent drugs against Plasmodium falciparium infection of humans, block efficiently the PA63-channel in a dose dependent way. Methodology/Principal Findings Here we demonstrate that related positively charged heterocyclic azolopyridinium salts block the PA63-channel in the µM range, when both, inhibitor and PA63 are added to the same side of the membrane, the cis-side, which corresponds to the lumen of acidified endosomal vesicles of target cells. Noise-analysis allowed the study of the kinetics of the plug formation by the heterocycles. In vivo experiments using J774A.1 macrophages demonstrated that the inhibitors of PA63-channel function also efficiently block intoxication of the cells by the combination lethal factor and PA63 in the same concentration range as they block the channels in vitro. Conclusions/Significance These results strongly argue in favor of a transport of lethal factor through the PA63-channel and suggest that the heterocycles used in this study could represent attractive candidates for development of novel therapeutic strategies against anthrax. PMID:23840407

Duscha, Kerstin; Riedl, Zsuzsanna; Huber-Lang, Markus; Benz, Roland; Hajos, Gyorgy; Barth, Holger

2013-01-01

49

Crystallographic studies of the anthrax lethal toxin. Final report, 1 July 1994-31 December 1996  

SciTech Connect

Protective Antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthraces, the organism responsible for anthrax. Following proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that translocates the toxic enzymes into the cytosol. We have solved the crystal structure of monomeric PA at 2.1 A resolution and the water-soluble heptamer at 4.5 A resolution. The monomer is organized mainly into antiparallel b-sheets and has four domains: an N-terminal domain containing two calcium ions; a heptamerization domain containing a large flexible loop implicated in membrane insertion; a small domain of unknown function; and a C-terminal receptor-binding domain. Removal of a 20 kDa fragment from the N-terminal domain permits assembly of the heptamer, a ring-shaped structure with a negatively charged lumen, and exposes a large hydrophobic surface for binding the toxic enzymes. We present a model of pH-dependent membrane insertion involving formation of a porin-like membrane-spanning b barrel. These studies greatly enhance current understanding of the mechanism of anthrax intoxication, and will be useful in the design of recombinant anthrax vaccines.

Frederick, C.A.

1997-01-01

50

Cardiac-specific catalase overexpression rescues anthrax lethal toxin-induced cardiac contractile dysfunction: role of oxidative stress and autophagy  

PubMed Central

Background Lethal and edema toxins secreted by Bacillus anthracis during anthrax infection were found to incite serious cardiovascular complications. However, the underlying mechanisms in anthrax lethal toxin-induced cardiac anomalies remain unknown. This study was designed to evaluate the impact of antioxidant enzyme catalase in anthrax lethal toxin-induced cardiomyocyte contractile dysfunction. Methods Wild type (WT) and cardiac-specific catalase overexpression mice were challenged with lethal toxin (2 ?g/g, intraperotineally (i.p.)). Cardiomyocyte contractile and intracellular Ca2+ properties were assessed 18 h later using an IonOptix edge-detection system. Proteasome function was assessed using chymotrypsin-like and caspase-like activities. GFP-LC3 puncta and Western blot analysis were used to evaluate autophagy and protein ubiquitination. Results Lethal toxin exposure suppressed cardiomyocyte contractile function (suppressed peak shortening, maximal velocity of shortening/re-lengthening, prolonged duration of shortening/re-lengthening, and impaired intracellular Ca2+ handling), the effects of which were alleviated by catalase. In addition, lethal toxin triggered autophagy, mitochondrial and ubiquitin-proteasome defects, the effects of which were mitigated by catalase. Pretreatment of cardiomyocytes from catalase mice with the autophagy inducer rapamycin significantly attenuated or ablated catalase-offered protection against lethal toxin-induced cardiomyocyte dysfunction. On the other hand, the autophagy inhibitor 3-MA ablated or significantly attenuated lethal toxin-induced cardiomyocyte contractile anomalies. Conclusions Our results suggest that catalase is protective against anthrax lethal toxin-induced cardiomyocyte contractile and intracellular Ca2+ anomalies, possibly through regulation of autophagy and mitochondrial function. PMID:23134810

2012-01-01

51

Involvement of Domain 3 in Oligomerization by the Protective Antigen Moiety of Anthrax Toxin  

PubMed Central

Protective antigen (PA), a component of anthrax toxin, binds receptors on mammalian cells and is activated by a cell surface protease. The resulting active fragment, PA63, forms ring-shaped heptamers, binds the enzymic moieties of the toxin, and translocates them to the cytosol. Of the four crystallographic domains of PA, domain 1 has been implicated in binding the enzymic moieties; domain 2 is involved in membrane insertion and oligomerization; and domain 4 binds receptor. To determine the function of domain 3, we developed a screen that allowed us to isolate random mutations that cause defects in the activity of PA. We identified several mutations in domain 3 that affect monomer-monomer interactions in the PA63 heptamer, indicating that this may be the primary function of this domain. PMID:11222612

Mogridge, Jeremy; Mourez, Michael; Collier, R. John

2001-01-01

52

Auranofin protects against anthrax lethal toxin-induced activation of the Nlrp1b inflammasome.  

PubMed

Anthrax lethal toxin (LT) is the major virulence factor for Bacillus anthracis. The lethal factor (LF) component of this bipartite toxin is a protease which, when transported into the cellular cytoplasm, cleaves mitogen-activated protein kinase kinase (MEK) family proteins and induces rapid toxicity in mouse macrophages through activation of the Nlrp1b inflammasome. A high-throughput screen was performed to identify synergistic LT-inhibitory drug combinations from within a library of approved drugs and molecular probes. From this screen we discovered that auranofin, an organogold compound with anti-inflammatory activity, strongly inhibited LT-mediated toxicity in mouse macrophages. Auranofin did not inhibit toxin transport into cells or MEK cleavage but inhibited both LT-mediated caspase-1 activation and caspase-1 catalytic activity. Thus, auranofin inhibited LT-mediated toxicity by preventing activation of the Nlrp1b inflammasome and the downstream actions that occur in response to the toxin. Idebenone, an analog of coenzyme Q, synergized with auranofin to increase its protective effect. We found that idebenone functions as an inhibitor of voltage-gated potassium channels and thus likely mediates synergy through inhibition of the potassium fluxes which have been shown to be required for Nlrp1b inflammasome activation. PMID:21149629

Newman, Zachary L; Sirianni, Nicole; Mawhinney, Christina; Lee, Margaret S; Leppla, Stephen H; Moayeri, Mahtab; Johansen, Lisa M

2011-03-01

53

Inhibition of Anthrax Lethal Toxin-Induced Cytolysis of RAW264.7 Cells by Celastrol  

PubMed Central

Background Bacillus anthracis is the bacterium responsible for causing anthrax. The ability of B. anthracis to cause disease is dependent on a secreted virulence factor, lethal toxin, that promotes survival of the bacteria in the host by impairing the immune response. A well-studied effect of lethal toxin is the killing of macrophages, although the molecular mechanisms involved have not been fully characterized. Methodology/Principal Findings Here, we demonstrate that celastrol, a quinone methide triterpene derived from a plant extract used in herbal medicine, inhibits lethal toxin-induced death of RAW264.7 murine macrophages. Celastrol did not prevent cleavage of mitogen activated protein kinase kinase 1, a cytosolic target of the toxin, indicating that it did not inhibit the uptake or catalytic activity of lethal toxin. Surprisingly, celastrol conferred almost complete protection when it was added up to 1.5 h after intoxication, indicating that it could rescue cells in the late stages of intoxication. Since the activity of the proteasome has been implicated in intoxication using other pharmacological agents, we tested whether celastrol blocked proteasome activity. We found that celastrol inhibited the proteasome-dependent degradation of proteins in RAW264.7 cells, but only slightly inhibited proteasome-mediated cleavage of fluorogenic substrates in vitro. Furthermore, celastrol blocked stimulation of IL-18 processing, indicating that celastrol acted upstream of inflammasome activation. Conclusions/Significance This work identifies celastrol as an inhibitor of lethal toxin-mediated macrophage lysis and suggests an inhibitory mechanism involving inhibition of the proteasome pathway. PMID:18183301

Chapelsky, Sarah; Batty, Sarah; Frost, Mia; Mogridge, Jeremy

2008-01-01

54

Structure-based Inhibitor Discovery against Adenylyl Cyclase Toxins from Pathogenic Bacteria That Cause Anthrax and  

E-print Network

That Cause Anthrax and Whooping Cough* Received for publication, February 4, 2003, and in revised form, March bacteria that cause anthrax and whooping cough, respectively. Using the structure of the catalytic site pathogenesis and to fight against anthrax and whooping cough. The 2001 anthrax attacks in the United States

Mrksich, Milan

55

Expression of Nlrp1b Inflammasome Components in Human Fibroblasts Confers Susceptibility to Anthrax Lethal Toxin ?  

PubMed Central

Anthrax lethal toxin causes macrophages and dendritic cells from some mouse strains to undergo caspase-1-dependent cell death. Central to this process is the NOD-like receptor Nlrp1b (Nalp1b), which detects intoxication and then self-associates to form a complex, termed an inflammasome, that is capable of activating the procaspase-1 zymogen. The nature of the signal detected directly by Nlrp1b is not known, and the mechanisms of inflammasome assembly are poorly understood. Here, we demonstrate that transfection of human fibroblasts with plasmids encoding murine Nlrp1b and procaspase-1 was sufficient to confer susceptibility to lethal toxin-mediated death on the cells. As has been observed in murine macrophages, the enzymatic activities of lethal toxin and the proteasome were both required for activation of the Nlrp1b inflammasome and this activation led to prointerleukin-1? processing. Release of interleukin-1? from cells was not dependent on cell lysis, as its secretion was not affected by an osmoprotectant that prevented the appearance of lactate dehydrogenase in the culture medium. We generated constitutively active mutants of Nlrp1b by making amino-terminal deletions to the protein and observed that the ability to activate procaspase-1 was dependent on the CARD domain, which bound procaspase-1, and a region adjacent to the CARD domain that promoted self-association. Our results demonstrate that lethal toxin can activate Nlrp1b in a nonmyeloid cell line and are consistent with work that suggests that activation induces proximity of procaspase-1. PMID:19651869

Liao, Kuo-Chieh; Mogridge, Jeremy

2009-01-01

56

Anthrax Lethal Toxin Promotes Dephosphorylation of TTP and Formation of Processing bodies  

PubMed Central

Anthrax lethal toxin (LeTx) is composed of protective antigen (PA) and lethal factor (LF) – PA is the receptor-binding moiety and LF is a protease that cleaves mitogen-activated protein kinase kinases (MAPKKs). LeTx subverts the immune response to B. anthracis in several ways, such as downregulating interleukin-8 (IL-8) by increasing the rate of IL-8 mRNA degradation. Many transcripts are regulated through cis-acting elements that bind proteins that either impede or promote degradation. Some of these RNA binding proteins are regulated by MAPKs and previous work has demonstrated that interfering with MAPK signaling decreases the half-life of IL-8 mRNA. Here, we have localized a segment within the IL-8 3? untranslated region responsible for LeTx-induced transcript destabilization and show that this is caused by inhibition of the p38, ERK, and JNK pathways. TTP, an RNA binding protein involved in IL-8 mRNA decay, became hypophosphorylated in LeTx-treated cells and knock-down of TTP prevented LeTx from destabilizing the IL-8 transcript. Cells that were treated with LeTx exhibited increased localization of TTP to Processing-bodies, which are structures that accumulate transcripts targeted for degradation. We furthermore observed that LeTx promoted the formation of Processing-bodies, revealing a link between the toxin and a major mRNA decay pathway. PMID:19995385

Chow, Edith M.C.; Batty, Sarah; Mogridge, Jeremy

2010-01-01

57

Synthesis and assembly of anthrax lethal factor-cholera toxin B-subunit fusion protein in transgenic potato  

Microsoft Academic Search

A DNA encoding the 27-kDa domain I of anthrax lethal factor protein (LF), was linked to the carboxyl terminus of the cholera\\u000a toxin B-subunit (CTB-LF). The CTB-LF fusion gene was transferred into Solanum tuberosum cells by Agrobacterium tumefaciens-mediated in vivo transformation methods and antibiotic-resistant plants were regenerated. The CTB-LF fusion gene was detected\\u000a in transformed potato leaf genomic DNA by

Tae-Geum Kim; Darrell R. Galloway; William H. R. Langridge

2004-01-01

58

Plant-Based Vaccine: Mice Immunized with Chloroplast-Derived Anthrax Protective Antigen Survive Anthrax Lethal Toxin Challenge  

Microsoft Academic Search

The currently available human vaccine for anthrax, derived from the culture supernatant of Bacillus anthracis, contains the protective antigen (PA) and traces of the lethal and edema factors, which may contribute to adverse side effects associated with this vaccine. Therefore, an effective expression system that can provide a clean, safe, and efficacious vaccine is required. In an effort to produce

Vijay Koya; Mahtab Moayeri; Stephen H. Leppla; Henry Daniell

2005-01-01

59

Cathepsin B-mediated Autophagy Flux Facilitates the Anthrax Toxin Receptor 2-mediated Delivery of Anthrax Lethal Factor into the Cytoplasm*  

PubMed Central

Anthrax lethal toxin (LeTx) is a virulence factor secreted by Bacillus anthracis and has direct cytotoxic effects on most cells once released into the cytoplasm. The cytoplasmic delivery of the proteolytically active component of LeTx, lethal factor (LF), is carried out by the transporter component, protective antigen, which interacts with either of two known surface receptors known as anthrax toxin receptor (ANTXR) 1 and 2. We found that the cytoplasmic delivery of LF by ANTXR2 was mediated by cathepsin B (CTSB) and required lysosomal fusion with LeTx-containing endosomes. Also, binding of protective antigen to ANXTR1 or -2 triggered autophagy, which facilitated the cytoplasmic delivery of ANTXR2-associated LF. We found that whereas cells treated with the membrane-permeable CTSB inhibitor CA074-Me- or CTSB-deficient cells had no defect in fusion of LC3-containing autophagic vacuoles with lysosomes, autophagic flux was significantly delayed. These results suggested that the ANTXR2-mediated cytoplasmic delivery of LF was enhanced by CTSB-dependent autophagic flux. PMID:19858192

Ha, Soon-Duck; Ham, Boram; Mogridge, Jeremy; Saftig, Paul; Lin, Shengcai; Kim, Sung Ouk

2010-01-01

60

Anthrax Infection  

PubMed Central

Bacillus anthracis infection is rare in developed countries. However, recent outbreaks in the United States and Europe and the potential use of the bacteria for bioterrorism have focused interest on it. Furthermore, although anthrax was known to typically occur as one of three syndromes related to entry site of (i.e., cutaneous, gastrointestinal, or inhalational), a fourth syndrome including severe soft tissue infection in injectional drug users is emerging. Although shock has been described with cutaneous anthrax, it appears much more common with gastrointestinal, inhalational (5 of 11 patients in the 2001 outbreak in the United States), and injectional anthrax. Based in part on case series, the estimated mortalities of cutaneous, gastrointestinal, inhalational, and injectional anthrax are 1%, 25 to 60%, 46%, and 33%, respectively. Nonspecific early symptomatology makes initial identification of anthrax cases difficult. Clues to anthrax infection include history of exposure to herbivore animal products, heroin use, or clustering of patients with similar respiratory symptoms concerning for a bioterrorist event. Once anthrax is suspected, the diagnosis can usually be made with Gram stain and culture from blood or surgical specimens followed by confirmatory testing (e.g., PCR or immunohistochemistry). Although antibiotic therapy (largely quinolone-based) is the mainstay of anthrax treatment, the use of adjunctive therapies such as anthrax toxin antagonists is a consideration. PMID:21852539

Sweeney, Daniel A.; Hicks, Caitlin W.; Cui, Xizhong; Li, Yan

2011-01-01

61

Protein- and DNA-based anthrax toxin vaccines confer protection in guinea pigs against inhalational challenge with Bacillus cereus G9241.  

PubMed

In the past decade, several Bacillus cereus strains have been isolated from otherwise healthy individuals who succumbed to bacterial pneumonia presenting symptoms resembling inhalational anthrax. One strain was indistinguishable from B. cereus G9241, previously cultured from an individual who survived a similar pneumonia-like illness and which was shown to possess a complete set of plasmid-borne anthrax toxin-encoding homologs. The finding that B. cereus G9241 pathogenesis in mice is dependent on pagA1-derived protective antigen (PA) synthesis suggests that an anthrax toxin-based vaccine may be effective against this toxin-encoding B. cereus strain. Dunkin Hartley guinea pigs were immunized with protein- and DNA-based anthrax toxin-based vaccines, immune responses were evaluated and survival rates were calculated after lethal aerosol exposure with B. cereus G9241 spores. Each vaccine induced seroconversion with the protein immunization regimen eliciting significantly higher serum levels of antigen-specific antibodies at the prechallenge time-point compared with the DNA-protein prime-boost immunization schedule. Complete protection against lethal challenge was observed in all groups with a detectable prechallenge serum titer of toxin neutralizing antibodies. For the first time, we demonstrated that the efficacy of fully defined anthrax toxin-based vaccines was protective against lethal B. cereus G9241 aerosol challenge in the guinea pig animal model. PMID:25044336

Palmer, John; Bell, Matt; Darko, Christian; Barnewall, Roy; Keane-Myers, Andrea

2014-11-01

62

Electrical graphene aptasensor for ultra-sensitive detection of anthrax toxin with amplified signal transduction.  

PubMed

Detection of the anthrax toxin, the protective antigen (PA), at the attomolar (aM) level is demonstrated by an electrical aptamer sensor based on a chemically derived graphene field-effect transistor (FET) platform. Higher affinity of the aptamer probes to PA in the aptamer-immobilized FET enables significant improvements in the limit of detection (LOD), dynamic range, and sensitivity compared to the antibody-immobilized FET. Transduction signal enhancement in the aptamer FET due to an increase in captured PA molecules results in a larger 30 mV/decade shift in the charge neutrality point (Vg,min ) as a sensitivity parameter, with the dynamic range of the PA concentration between 12 aM (LOD) and 120 fM. An additional signal enhancement is obtained by the secondary aptamer-conjugated gold nanoparticles (AuNPs-aptamer), which have a sandwich structure of aptamer/PA/aptamer-AuNPs, induce an increase in charge-doping in the graphene channel, resulting in a reduction of the LOD to 1.2 aM with a three-fold increase in the Vg,min shift. PMID:23589198

Kim, Duck-Jin; Park, Hae-Chul; Sohn, Il Yung; Jung, Jin-Heak; Yoon, Ok Ja; Park, Joon-Shik; Yoon, Moon-Young; Lee, Nae-Eung

2013-10-11

63

Anthrax toxin lethal factor domain 3 is highly mobile and responsive to ligand binding.  

PubMed

The secreted anthrax toxin consists of three components: the protective antigen (PA), edema factor (EF) and lethal factor (LF). LF, a zinc metalloproteinase, compromises the host immune system primarily by targeting mitogen-activated protein kinase kinases in macrophages. Peptide substrates and small-molecule inhibitors bind LF in the space between domains 3 and 4 of the hydrolase. Domain 3 is attached on a hinge to domain 2 via residues Ile300 and Pro385, and can move through an angular arc of greater than 35° in response to the binding of different ligands. Here, multiple LF structures including five new complexes with co-crystallized inhibitors are compared and three frequently populated LF conformational states termed `bioactive', `open' and `tight' are identified. The bioactive position is observed with large substrate peptides and leaves all peptide-recognition subsites open and accessible. The tight state is seen in unliganded and small-molecule complex structures. In this state, domain 3 is clamped over certain substrate subsites, blocking access. The open position appears to be an intermediate state between these extremes and is observed owing to steric constraints imposed by specific bound ligands. The tight conformation may be the lowest-energy conformation among the reported structures, as it is the position observed with no bound ligand, while the open and bioactive conformations are likely to be ligand-induced. PMID:25372673

Maize, Kimberly M; Kurbanov, Elbek K; De La Mora-Rey, Teresa; Geders, Todd W; Hwang, Dong Jin; Walters, Michael A; Johnson, Rodney L; Amin, Elizabeth A; Finzel, Barry C

2014-11-01

64

Anthrax Lethal Toxin Triggers the Formation of a Membrane-Associated Inflammasome Complex in Murine Macrophages?  

PubMed Central

Multiple microbial components trigger the formation of an inflammasome complex that contains pathogen-specific nucleotide oligomerization and binding domain (NOD)-like receptors (NLRs), caspase-1, and in some cases the scaffolding protein ASC. The NLR protein Nalp1b has been linked to anthrax lethal toxin (LT)-mediated cytolysis of murine macrophages. Here we demonstrate that in unstimulated J774A.1 macrophages, caspase-1 and Nalp1b are membrane associated and part of ?200- and ?800-kDa complexes, respectively. LT treatment of these cells resulted in caspase-1 recruitment to the Nalp1b-containing complex, concurrent with processing of cytosolic caspase-1 substrates. We further demonstrated that Nalp1b and caspase-1 are able to interact with each other. Intriguingly, both caspase-1 and Nalp1b were membrane associated, while the caspase-1 substrate interleukin-18 was cytosolic. Caspase-1-associated inflammasome components included, besides Nalp1b, proinflammatory caspase-11 and the caspase-1 substrate ?-enolase. Asc was not part of the Nalp1b inflammasome in LT-treated macrophages. Taken together, our findings suggest that LT triggers the formation of a membrane-associated inflammasome complex in murine macrophages, resulting in cleavage of cytosolic caspase-1 substrates and cell death. PMID:19124602

Nour, Adel M.; Yeung, Yee-Guide; Santambrogio, Laura; Boyden, Eric D.; Stanley, E. Richard; Brojatsch, Jurgen

2009-01-01

65

Binding of filamentous actin to anthrax toxin receptor 1 decreases its association with protective antigen  

PubMed Central

ANTXR1 is a Type I membrane protein that binds the protective antigen (PA) component of anthrax toxin. The cytosolic domain of ANTXR1 has a novel actin-binding region that influences the interaction of the ectodomain with PA. Here, we have investigated features of the cytosolic domain of ANTXR1 that reduce the association of the receptor with PA. We mutated a stretch of conserved acidic amino acids adjacent to the actin-binding region and found that the mutation increased the affinity for monomeric actin in vitro. ANTXR1 bearing this mutation exhibited increased association with the cytoskeleton and bound less PA compared to the wild-type receptor, confirming the inverse correlation between the two interactions. To determine whether binding of actin is sufficient to regulate the ectodomain, we replaced the actin-binding region of ANTXR1 with that from the yeast protein abp140 and with the WH2 domain of WAVE2. Although both of these domains bound monomeric actin in vitro, only the sequence from abp140 reduced binding of PA to a hybrid receptor. The actin binding regions of ANTXR1 and abp140, but not the WH2 domain, colocalized with actin stress fibres, which suggested that filamentous actin regulates ANTXR1. Consistent with this notion, disruption of actin filaments using latrunculin A increased the amount of PA bound to cells. This work provides evidence that cytoskeletal dynamics regulate ANTXR1 function. PMID:22303962

Garlick, Kristopher M.; Batty, Sarah; Mogridge, Jeremy

2012-01-01

66

The Cytoplasmic Domain of Anthrax Toxin Receptor 1 Affects Binding of the Protective Antigen?  

PubMed Central

The protective antigen (PA) component of anthrax toxin binds the I domain of the receptor ANTXR1. Integrin I domains convert between open and closed conformations that bind ligand with high and low affinities, respectively; this process is regulated by signaling from the cytoplasmic domains. To assess whether intracellular signals might influence the interaction between ANTXR1 and PA, we compared two splice variants of ANTXR1 that differ only in their cytoplasmic domains. We found that cells expressing ANTXR1 splice variant 1 (ANTXR1-sv1) bound markedly less PA than did cells expressing a similar level of the shorter splice variant ANTXR1-sv2. ANTXR1-sv1 but not ANTXR1-sv2 associated with the actin cytoskeleton, although disruption of the cytoskeleton did not affect binding of ANTXR-sv1 to PA. Introduction of a cytoplasmic domain missense mutation found in the related receptor ANTXR2 in a patient with juvenile hyaline fibromatosis impaired actin association and increased binding of PA to ANTXR1-sv1. These results suggest that ANTXR1 has two affinity states that may be modulated by cytoplasmic signals. PMID:18936178

Go, Mandy Y.; Chow, Edith M. C.; Mogridge, Jeremy

2009-01-01

67

Delivery of Antibody Mimics into Mammalian Cells via Anthrax Toxin Protective Antigen.  

PubMed

Antibody mimics have significant scientific and therapeutic utility for the disruption of protein-protein interactions inside cells; however, their delivery to the cell cytosol remains a major challenge. Here we show that protective antigen (PA), a component of anthrax toxin, efficiently transports commonly used antibody mimics to the cytosol of mammalian cells when conjugated to the N-terminal domain of LF (LFN ). In contrast, a cell-penetrating peptide (CPP) was not able to deliver any of these antibody mimics into the cell cytosol. The refolding and binding of a transported tandem monobody to Bcr-Abl (its protein target) in chronic myeloid leukemia cells were confirmed by co-immunoprecipitation. We also observed inhibition of Bcr-Abl kinase activity and induction of apoptosis caused by the monobody. In a separate case, we show disruption of key interactions in the MAPK signaling pathway after PA-mediated delivery of an affibody binder that targets hRaf-1. We show for the first time that PA can deliver bioactive antibody mimics to disrupt intracellular protein-protein interactions. This technology adds a useful tool to expand the applications of these modern agents to the intracellular milieu. PMID:25250705

Liao, Xiaoli; Rabideau, Amy E; Pentelute, Bradley L

2014-11-01

68

Human anti-anthrax protective antigen neutralizing monoclonal antibodies derived from donors vaccinated with anthrax vaccine adsorbed  

Microsoft Academic Search

BACKGROUND: Potent anthrax toxin neutralizing human monoclonal antibodies were generated from peripheral blood lymphocytes obtained from Anthrax Vaccine Adsorbed (AVA) immune donors. The anti-anthrax toxin human monoclonal antibodies were evaluated for neutralization of anthrax lethal toxin in vivo in the Fisher 344 rat bolus toxin challenge model. METHODS: Human peripheral blood lymphocytes from AVA immunized donors were engrafted into severe

Ritsuko Sawada-Hirai; Ivy Jiang; Fei Wang; Shu Man Sun; Rebecca Nedellec; Paul Ruther; Alejandro Alvarez; Diane Millis; Phillip R Morrow; Angray S Kang

2004-01-01

69

Quantitative anti-PA IgG ELISA; assessment and comparability with the anthrax toxin neutralization assay in goats  

PubMed Central

Background Presently, few data exist on the level and duration of anti-protective antigen (PA) IgG in vaccinated livestock. Various adaptation of enzyme-linked immunosorbent assays (ELISAs) have been developed in studies to assess immune response following vaccination, albeit mostly in laboratory rodent models. The quantitative anti-anthrax IgG ELISA in this study describes a method of enumerating the concentration of anti-PA specific IgG present in sera of immunized goats, with the aid of an affinity-purified caprine polyclonal anti-anthrax PA-83 IgG standard. This was compared with the anthrax toxin neutralization assay (TNA) which measures a functional subset of toxin neutralizing anti-PA IgG. Results The measured concentrations obtained in the standard curve correlated with the known concentration at each dilution. Percentage recovery of the standard concentrations ranged from 89 to 98% (lower and upper asymptote respectively). Mean correlation coefficient (r2) of the standard curve was 0.998. Evaluation of the intra-assay coefficient of variation showed ranges of 0.23-16.90% and 0.40-12.46% for days 28 and 140 sera samples respectively, following vaccination. The mean inter-assay coefficient of variation for triplicate samples repeated on 5 different days was 18.53 and 12.17% for days 28 and 140 sera samples respectively. Spearman’s rank correlation of log-transformed IgG concentrations and TNA titres showed strong positive correlation (rs?=?0.942; p?=?0.01). Conclusion This study provides evidence that an indirect ELISA can be used for the quantification of anti-anthrax PA IgG in goats with the added advantage of using single dilutions to save time and resources. The use of such related immunoassays can serve as potential adjuncts to potency tests for Sterne and other vaccine types under development in ruminant species. This is the first report on the correlation of polyclonal anti-anthrax PA83 antibody with the TNA in goats. PMID:24373579

2013-01-01

70

Erythrocytic Mobilization Enhanced by the Granulocyte Colony-Stimulating Factor Is Associated with Reduced Anthrax-Lethal-Toxin-Induced Mortality in Mice  

PubMed Central

Anthrax lethal toxin (LT), one of the primary virulence factors of Bacillus anthracis, causes anthrax-like symptoms and death in animals. Experiments have indicated that levels of erythrocytopenia and hypoxic stress are associated with disease severity after administering LT. In this study, the granulocyte colony-stimulating factor (G-CSF) was used as a therapeutic agent to ameliorate anthrax-LT- and spore-induced mortality in C57BL/6J mice. We demonstrated that G-CSF promoted the mobilization of mature erythrocytes to peripheral blood, resulting in a significantly faster recovery from erythrocytopenia. In addition, combined treatment using G-CSF and erythropoietin tended to ameliorate B. anthracis-spore-elicited mortality in mice. Although specific treatments against LT-mediated pathogenesis remain elusive, these results may be useful in developing feasible strategies to treat anthrax. PMID:25384016

Chang, Hsin-Hou; Chiang, Ya-Wen; Lin, Ting-Kai; Lin, Guan-Ling; Lin, You-Yen; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Hsu, Hui-Ling; Wang, Jen-Hung; Sun, Der-Shan

2014-01-01

71

Anthrax Toxin Receptor 2 Functions in ECM Homeostasis of the Murine Reproductive Tract and Promotes MMP Activity  

PubMed Central

Anthrax Toxin Receptor proteins function as receptors for anthrax toxin, however physiological activity remains unclear. To evaluate the biological role of Antxr2, we generated Antxr2?/? mice. Antxr2?/? mice were viable, however Antxr2 is required for parturition in young females and for preserving fertility in older female mice. Histological analysis of the uterus and cervix revealed aberrant deposition of extracellular matrix proteins such as type I collagen, type VI collagen and fibronectin. A marked disruption of both the circular and longitudinal myometrial cell layers was evident in Antxr2?/? mice. These changes progressed as the mice aged, resulting in a thickened, collagen dense, acellular stroma and the disappearance of normal uterine architecture. To investigate the molecular mechanism underlying the uterine fibrosis we performed immunoblotting for MMP2 using uterine lysates and zymography using conditioned medium from Antxr2?/? mouse embryonic fibroblasts and found reduced levels of activated MMP2 in both. This prompted us to investigate MT1-MMP status, as MMP2 processing is regulated by MT1-MMP. We found MT1-MMP activity, as measured by MMP2 processing and activation, was enhanced by expression of either ANTXR1 or ANTXR2. We identified an ANTXR2/MT1-MMP complex and demonstrated that MT1-MMP activity is dependent on ANTXR2 expression levels in cells. Thus, we have discovered that ANTXR1 and ANTXR2 function as positive regulators of MT1-MMP activity. PMID:22529944

Reeves, Claire V.; Wang, Xing; Charles-Horvath, Pelisa C.; Vink, Joy Y.; Borisenko, Valeriya Y.; Young, John A. T.; Kitajewski, Jan K.

2012-01-01

72

The lethal and edema factors of anthrax toxin bind only to oligomeric forms of the protective antigen  

PubMed Central

The three proteins that comprise anthrax toxin, edema factor (EF), lethal factor (LF), and protective antigen (PA), assemble at the mammalian cell surface into toxic complexes. After binding to its receptor, PA is proteolytically activated, yielding a carboxyl-terminal 63-kDa fragment (PA63) that coordinates assembly of the complexes, promotes their endocytosis, and translocates EF and LF to the cytosol. PA63 spontaneously oligomerizes to form symmetric ring-shaped heptamers that are capable of binding three molecules of EF and/or LF as competing ligands. To determine whether binding of these ligands depends on oligomerization of PA63, we prepared two oligomerization-deficient forms of this protein, each mutated on a different PA63–PA63 contact face. In solution or when bound to receptors on Chinese hamster ovary K1 cells, neither mutant alone bound ligand, but a mixture of them did. After the two mutants were proteolytically activated and mixed with ligand in solution, a ternary complex was isolated containing one molecule of each protein. Thus EF and LF bind stably only to PA63 dimers or higher order oligomers. These findings are relevant to the kinetics and pathways of assembly of anthrax toxin complexes. PMID:11997437

Mogridge, Jeremy; Cunningham, Kristina; Lacy, D. Borden; Mourez, Michael; Collier, R. John

2002-01-01

73

A protective antigen mutation increases the pH threshold of anthrax toxin receptor 2-mediated pore formation.  

PubMed

Anthrax toxin protective antigen (PA) binds cellular receptors and self-assembles into oligomeric prepores. A prepore converts to a protein translocating pore after it has been transported to an endosome where the low pH triggers formation of a membrane-spanning ?-barrel channel. Formation of this channel occurs after some PA-receptor contacts are broken to allow pore formation, while others are retained to preserve receptor association. The interaction between PA and anthrax toxin receptor 1 (ANTXR1) is weaker than its interaction with ANTXR2 such that the pH threshold of ANTXR1-mediated pore formation is higher by 1 pH unit. Here we examine receptor-specific differences in toxin binding and pore formation by mutating PA residue G342 that selectively abuts ANTXR2. Mutation of G342 to valine, leucine, isoleucine, or tryptophan increased the amount of PA bound to ANTXR1-expressing cells and decreased the amount of PA bound to ANTXR2-expressing cells. The more conservative G342A mutation did not affect the level of binding to ANTXR2, but ANTXR2-bound PA-G342A prepores exhibited a pH threshold higher than that of wild-type prepores. Mixtures of wild-type PA and PA-G342A were functional in toxicity assays, and the pH threshold of ANTXR2-mediated pore formation was dictated by the relative amounts of the two proteins in the hetero-oligomers. These results suggest that PA subunits within an oligomer do not have to be triggered simultaneously for a productive membrane insertion event to occur. PMID:24641616

Dennis, Melissa K; Mogridge, Jeremy

2014-04-01

74

Tumor therapy with a urokinase plasminogen activator-activated anthrax lethal toxin alone and in combination with paclitaxel.  

PubMed

PA-U2, an engineered anthrax protective antigen that is activated by urokinase was combined with wildtype lethal factor in the treatment of Colo205 colon adenocarcinoma in vitro and B16-BL6 mouse melanoma in vitro and in vivo. This therapy was also tested in combination with the small molecule paclitaxel, based on prior reports suggesting synergy between ERK1/2 inhibition and chemotherapeutics. Colo205 was sensitive to PA-U2/LF while B16-BL6 was not. For the combination treatment of B16-BL6, paclitaxel showed a dose response in vitro, but cells remained resistant to PA-U2/LF even in the presence of paclitaxel. In vivo, each therapy slowed tumor progression, and an additive effect between the two was observed. Since LF targets tumor vasculature while paclitaxel is an antimitotic, it is possible the agents were acting against different cells in the stroma, precluding a synergistic effect. The engineered anthrax toxin PA-U2/LF warrants further development and testing, possibly in combination with an antiangiogenesis therapy such as sunitinib or sorafinib. PMID:22843210

Wein, Alexander N; Liu, Shihui; Zhang, Yi; McKenzie, Andrew T; Leppla, Stephen H

2013-02-01

75

The Design of Potent Liposome-Based Inhibitors of Anthrax Toxin  

Microsoft Academic Search

Several biological processes involve the recognition of a specific pattern of binding sites on a target surface. Theoreticians have predicted that endowing synthetic biomimetic structures with statistical pattern matching capabilities may impact the development of sensors and separation processes. We demonstrated for the first time that statistical pattern matching significantly enhances the potency of a polyvalent therapeutic -- an anthrax

Prakash Rai; Chakradhar Padala; Vincent Poon; Arundhati Saraph; Saleem Basha; Sandesh Kate; Kevin Tao; Jeremy Mogridge; Ravi Kane

2006-01-01

76

Detection of Anthrax Toxin by an Ultrasensitive Immunoassay Using Europium Nanoparticles  

Microsoft Academic Search

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

Shixing Tang; Mahtab Moayeri; Zhaochun Chen; Harri Harma; Jiangqin Zhao; Haijing Hu; Robert H. Purcell; Stephen H. Leppla; Indira K. Hewlett

2009-01-01

77

Effect of delayed anthrax vaccine dose on Bacillus anthracis protective antigen IgG response and lethal toxin neutralization activity.  

PubMed

We describe the Bacillus anthracis protective antigen IgG antibody response and the B. anthracis lethal toxin neutralization activity to a delayed dose of anthrax vaccine adsorbed (AVA, BioThrax(®)) using validated assays. 373 individuals received 1, 2, or 3 priming doses, 18-24 months afterward, they received a delayed dose of AVA. Overall, 23.6% of subjects showed detectable anti-PA IgG before the boost, compared to 99.2% (P<0.0001) 28 days after the boost. Geometric mean anti-PA IgG concentration (GMC) was 1.66 ?g/mL before and 887.82 ?g/mL after the boost (P<0.0001). The proportion of individuals with four-fold increase in GMC following the boost ranged from 93.8% to 100%. Robust anti-PA IgG levels and B. anthracis lethal toxin neutralization activity are induced when an AVA dose is delayed as long as two years. These data support continuing with the vaccination schedule when a dose is delayed as long as two years rather than restarting the series. PMID:24026013

Pittman, Phillip R; Fisher, Diana; Quinn, Xiaofei; Schmader, Trevor; Barrera-Oro, Julio G

2013-10-17

78

Identification of a Receptor-Binding Region within Domain 4 of the Protective Antigen Component of Anthrax Toxin  

PubMed Central

Anthrax toxin from Bacillus anthracis is a three-component toxin consisting of lethal factor (LF), edema factor (EF), and protective antigen (PA). LF and EF are the catalytic components of the toxin, whereas PA is the receptor-binding component. To identify residues of PA that are involved in interaction with the cellular receptor, two solvent-exposed loops of domain 4 of PA (amino acids [aa] 679 to 693 and 704 to 723) were mutagenized, and the altered proteins purified and tested for toxicity in the presence of LF. In addition to the intended substitutions, novel mutations were introduced by errors that occurred during PCR. Substitutions within the large loop (aa 704 to 723) had no effect on PA activity. A mutated protein, LST-35, with three substitutions in the small loop (aa 679 to 693), bound weakly to the receptor and was nontoxic. A mutated protein, LST-8, with changes in three separate regions did not bind to receptor and was nontoxic. Toxicity was greatly decreased by truncation of the C-terminal 3 to 5 aa, but not by their substitution with nonnative residues or the extension of the terminus with nonnative sequences. Comparison of the 28 mutant proteins described here showed that the large loop (aa 704 to 722) is not involved in receptor binding, whereas residues in and near the small loop (aa 679 to 693) play an important role in receptor interaction. Other regions of domain 4, in particular residues at the extreme C terminus, appear to play a role in stabilizing a conformation needed for receptor-binding activity. PMID:10085028

Varughese, Mini; Teixeira, Avelino V.; Liu, Shihui; Leppla, Stephen H.

1999-01-01

79

HDAC8-mediated epigenetic reprogramming plays a key role in resistance to anthrax lethal toxin-induced pyroptosis in macrophages*  

PubMed Central

Macrophages pre-exposed to a sub-lethal dose of anthrax lethal toxin (LeTx) are refractory to subsequent high cytolytic doses of LeTx, termed toxin-induced resistance (TIR). A small population of TIR cells (2–4%) retains TIR characteristics for up to 5 to 6 weeks. Through studying these long-term TIR cells, we found that a high level of histone deacetylase (HDAC)8 expression was crucial for TIR. Knocking down or inhibition of HDAC8 by siRNAs or the HDAC8-specific inhibitor PCI-34051, respectively, induced expression of the mitochondrial death genes Bcl2 Adenovirus E1B 19 kDa-interacting protein 3 (BNIP3), BNIP3-like (BNIP3L) and Metastatic Lymph Node (MLN)64, and re-sensitized TIR cells to LeTx. Among multiple histone acetylations, histone H3 lysine 27 acetylation (H3K27Ac) was most significantly decreased in TIR cells in an HDAC8-dependent manner, and the association of H3K27Ac with the genomic regions of BNIP3 and MLN64, where HDAC8 was recruited to, was diminished in TIR cells. Furthermore, over-expression of HDAC8 or knocking down the histone acetyltransferase CREB-binding protein (CBP)/p300, known to target H3K27, rendered wild-type cells resistant to LeTx. As in RAW264.7 cells, primary bone marrow-derived macrophages exposed to a sub-lethal dose of LeTx were resistance to LeTx in an HDAC8-dependent manner. Collectively, this study demonstrates that epigenetic reprogramming mediated by HDAC8 plays a key role in determining the susceptibility of LeTx-induced pyroptosis in macrophages. PMID:24973453

Ha, Soon-Duck; Han, Chae Young; Reid, Chantelle; Kim, Sung Ouk

2014-01-01

80

Combinations of monoclonal antibodies to anthrax toxin manifest new properties in neutralization assays.  

PubMed

Monoclonal antibodies (MAbs) are potential therapeutic agents against Bacillus anthracis toxins, since there is no current treatment to counteract the detrimental effects of toxemia. In hopes of isolating new protective MAbs to the toxin component lethal factor (LF), we used a strain of mice (C57BL/6) that had not been used in previous studies, generating MAbs to LF. Six LF-binding MAbs were obtained, representing 3 IgG isotypes and one IgM. One MAb (20C1) provided protection from lethal toxin (LeTx) in an in vitro mouse macrophage system but did not provide significant protection in vivo. However, the combination of two MAbs to LF (17F1 and 20C1) provided synergistic increases in protection both in vitro and in vivo. In addition, when these MAbs were mixed with MAbs to protective antigen (PA) previously generated in our laboratory, these MAb combinations produced synergistic toxin neutralization in vitro. But when 17F1 was combined with another MAb to LF, 19C9, the combination resulted in enhanced lethal toxicity. While no single MAb to LF provided significant toxin neutralization, LF-immunized mice were completely protected from infection with B. anthracis strain Sterne, which suggested that a polyclonal response is required for effective toxin neutralization. In total, these studies show that while a single MAb against LeTx may not be effective, combinations of multiple MAbs may provide the most effective form of passive immunotherapy, with the caveat that these may demonstrate emergent properties with regard to protective efficacy. PMID:23509144

Pohl, Mary Ann; Rivera, Johanna; Nakouzi, Antonio; Chow, Siu-Kei; Casadevall, Arturo

2013-06-01

81

Two independent replicons can support replication of the anthrax toxin-encoding plasmid pXO1 of Bacillus anthracis  

PubMed Central

The large pXO1 plasmid (181.6 kb) of Bacillus anthracis encodes the anthrax toxin proteins. Previous studies have shown that two separate regions of pXO1 can support replication of pXO1 miniplasmids when introduced into plasmid-less strains of this organism. No information is currently available on the ability of the above two replicons, termed RepX and ORFs 14/16 replicons, to support replication of the full-length pXO1 plasmid. We generated mutants of the full-length pXO1 plasmid in which either the RepX or the ORFs 14/16 replicon was inactivated by TargeTron insertional mutagenesis. Plasmid pXO1 derivatives containing only the RepX or the ORFs 14/16 replicon were able to replicate when introduced into a plasmid-less B. anthracis strain. Plasmid copy number analysis showed that the ORFs 14/16 replicon is more efficient than the RepX replicon. Our studies demonstrate that both the RepX and ORFs 14/16 replicons can independently support the replication of the full-length pXO1 plasmid. PMID:22239982

Akhtar, Parvez; Khan, Saleem A.

2014-01-01

82

Hyaline Fibromatosis Syndrome inducing mutations in the ectodomain of anthrax toxin receptor 2 can be rescued by proteasome inhibitors  

PubMed Central

Hyaline Fibromatosis Syndrome (HFS) is a human genetic disease caused by mutations in the anthrax toxin receptor 2 (or cmg2) gene, which encodes a membrane protein thought to be involved in the homeostasis of the extracellular matrix. Little is known about the structure and function of the protein or the genotype–phenotype relationship of the disease. Through the analysis of four patients, we identify three novel mutants and determine their effects at the cellular level. Altogether, we show that missense mutations that map to the extracellular von Willebrand domain or the here characterized Ig-like domain of CMG2 lead to folding defects and thereby to retention of the mutated protein in the endoplasmic reticulum (ER). Mutations in the Ig-like domain prevent proper disulphide bond formation and are more efficiently targeted to ER-associated degradation. Finally, we show that mutant CMG2 can be rescued in fibroblasts of some patients by treatment with proteasome inhibitors and that CMG2 is then properly transported to the plasma membrane and signalling competent, identifying the ER folding and degradation pathway components as promising drug targets for HFS. PMID:21328543

Deuquet, Julie; Lausch, Ekkehart; Guex, Nicolas; Abrami, Laurence; Salvi, Suzanne; Lakkaraju, Asvin; Ramirez, Maria Celeste M; Martignetti, John A; Rokicki, Dariusz; Bonafe, Luisa; Superti-Furga, Andrea; van der Goot, Francoise G

2011-01-01

83

Hyaline fibromatosis syndrome inducing mutations in the ectodomain of anthrax toxin receptor 2 can be rescued by proteasome inhibitors.  

PubMed

Hyaline Fibromatosis Syndrome (HFS) is a human genetic disease caused by mutations in the anthrax toxin receptor 2 (or cmg2) gene, which encodes a membrane protein thought to be involved in the homeostasis of the extracellular matrix. Little is known about the structure and function of the protein or the genotype–phenotype relationship of the disease. Through the analysis of four patients, we identify three novel mutants and determine their effects at the cellular level. Altogether, we show that missense mutations that map to the extracellular von Willebrand domain or the here characterized Ig-like domain of CMG2 lead to folding defects and thereby to retention of the mutated protein in the endoplasmic reticulum (ER). Mutations in the Ig-like domain prevent proper disulphide bond formation and are more efficiently targeted to ER-associated degradation. Finally, we show that mutant CMG2 can be rescued in fibroblasts of some patients by treatment with proteasome inhibitors and that CMG2 is then properly transported to the plasma membrane and signalling competent, identifying the ER folding and degradation pathway components as promising drug targets for HFS. PMID:21328543

Deuquet, Julie; Lausch, Ekkehart; Guex, Nicolas; Abrami, Laurence; Salvi, Suzanne; Lakkaraju, Asvin; Ramirez, Maria Celeste M; Martignetti, John A; Rokicki, Dariusz; Bonafe, Luisa; Superti-Furga, Andrea; van der Goot, Françoise G

2011-04-01

84

Selection of anthrax toxin protective antigen variants that discriminate between the cellular receptors TEM8 and CMG2 and achieve targeting of tumor cells.  

PubMed

Anthrax toxin, a three-component protein toxin secreted by Bacillus anthracis, assembles into toxic complexes at the surface of receptor-bearing eukaryotic cells. The protective antigen (PA) protein binds to receptors, either tumor endothelial cell marker 8 (TEM8) or CMG2 (capillary morphogenesis protein 2), and orchestrates the delivery of the lethal and edema factors into the cytosol. TEM8 is reported to be overexpressed during tumor angiogenesis, whereas CMG2 is more widely expressed in normal tissues. To extend prior work on targeting of tumor with modified anthrax toxins, we used phage display to select PA variants that preferentially bind to TEM8 as compared with CMG2. Substitutions were randomly introduced into residues 605-729 of PA, within the C-terminal domain 4 of PA, which is the principal region that contacts receptor. Candidates were characterized in cellular cytotoxicity assays with Chinese hamster ovary (CHO) cells expressing either TEM8 or CMG2. A PA mutant having the substitutions R659S and M662R had enhanced specificity toward TEM8-overexpressing CHO cells. This PA variant also displayed broad and potent tumoricidal activity to various human tumor cells, especially to HeLa and A549/ATCC cells. By contrast, the substitution N657Q significantly reduced toxicity to TEM8 but not CMG2-overexpressing CHO cells. Our results indicate that certain amino acid substitutions within PA domain 4 create anthrax toxins that selectively kill human tumor cells. The PA R659S/M662R protein may be useful as a therapeutic agent for cancer treatment. PMID:17251181

Chen, Kuang-Hua; Liu, Shihui; Bankston, Laurie A; Liddington, Robert C; Leppla, Stephen H

2007-03-30

85

SELECTION OF ANTHRAX TOXIN PROTECTIVE ANTIGEN VARIANTS THAT DISCRIMINATE BETWEEN THE CELLULAR RECEPTORS TEM8 AND CMG2 AND ACHIEVE TARGETING OF TUMOR CELLS  

PubMed Central

Anthrax toxin, a three-component protein toxin secreted by Bacillus anthracis, assembles into toxic complexes at the surface of receptor-bearing eukaryotic cells. The protective antigen (PA) protein binds to receptors, either tumor endothelial cell marker 8 (TEM8) or capillary morphogenesis protein 2 (CMG2), and orchestrates the delivery of the lethal and edema factors into the cytosol. TEM8 is reported to be over-expressed during tumor angiogenesis, whereas CMG2 is more widely expressed in normal tissues. To extend prior work on targeting of tumor with modified anthrax toxins, we used phage display to select PA variants that preferentially bind to TEM8 as compared to CMG2. Substitutions were randomly introduced into residues 605-729 of PA, within the C-terminal domain 4 of PA, which is the principal region that contacts receptor. Candidates were characterized in cellular cytotoxicity assays with CHO cells expressing either TEM8 or CMG2. A PA mutant having the substitutions R659S and M662R had enhanced specificity toward TEM8 over-expressing CHO cells. This PA variant also displayed broad and potent tumoricidal activity to various human tumor cells, especially to HeLa and A549/ATCC cells. By contrast, the substitution N657Q significantly reduced toxicity to TEM8 but not CMG2 over-expressing CHO cells. Our results indicate that certain amino acid substitutions within PA domain 4 create anthrax toxins that selectively kill human tumor cells. The PA R659S/M662R protein may be useful as a therapeutic agent for cancer treatment. PMID:17251181

Chen, Kuang-Hua; Liu, Shihui; Bankston, Laurie A.; Liddington, Robert C.; Leppla, Stephen H.

2008-01-01

86

Rapid Vascular Responses to Anthrax Lethal Toxin in Mice Containing a Segment of Chromosome 11 from the CAST\\/Ei Strain on a C57BL\\/6 Genetic Background  

Microsoft Academic Search

Host allelic variation controls the response to B. anthracis and the disease course of anthrax. Mouse strains with macrophages that are responsive to anthrax lethal toxin (LT) show resistance to infection while mouse strains with LT non-responsive macrophages succumb more readily. B6.CAST.11M mice have a region of chromosome 11 from the CAST\\/Ei strain (a LT responsive strain) introgressed onto a

Kelsey J. Weigel; Laura Rues; Edward J. Doyle; Cassandra L. Buchheit; John G. Wood; Ryan J. Gallagher; Laura E. Kelly; Jeffrey D. Radel; Kenneth A. Bradley; Steven M. LeVine

2012-01-01

87

Monitoring the kinetics of the pH driven transition of the anthrax toxin prepore to the pore by biolayer interferometry and surface plasmon resonance  

PubMed Central

Domain 2 of the anthrax protective antigen (PA) prepore heptamer unfolds and refolds during endosome acidification to generate an extended 100 Å beta barrel pore that inserts into the endosomal membrane. The PA pore facilitates the pH dependent unfolding and translocation of bound toxin enzymic components, lethal factor (LF) and/or edema factor (EF), from the endosome into the cytoplasm. We constructed immobilized complexes of the prepore with the PA-binding domain of LF (LFN) to monitor the real-time prepore to pore kinetic transition using surface plasmon resonance (SPR) and bio-layer interferometry (BLI). The kinetics of this transition increased as the solution pH was decreased from pH 7.5 to pH 5.0, mirroring acidification of the endosome. Once transitioned, the LFN-PA pore complex was removed from the BLI biosensor tip and deposited onto EM grids, where the PA pore formation was confirmed by negative stain electron microscopy. When the soluble receptor domain (ANTRX2/CMG2) binds the immobilized PA prepore, the transition to the pore state was observed only after the pH was lowered to early or late endosomal pH conditions (5.5 to 5.0 respectively). Once the pore formed, the soluble receptor readily dissociated from the PA pore. Separate binding experiments with immobilized PA pores and soluble receptor indicate that the receptor has a weakened propensity to bind to the transitioned pore. This immobilized anthrax toxin platform can be used to identify or validate potential antimicrobial lead compounds capable of regulating and/or inhibiting anthrax toxin complex formation or pore transitions. PMID:23964683

Naik, Subhashchandra; Brock, Susan; Akkaladevi, Narahari; Tally, Jon; Mcginn-Straub, Wesley; Zhang, Na; Gao, Phillip; Gogol, E. P.; Pentelute, B. L.; Collier, R. John; Fisher, Mark T.

2013-01-01

88

Anthrax X-rayed: new opportunities for biodefence  

Microsoft Academic Search

Bacillus anthracis, the agent responsible for inhalation anthrax, exerts its lethal effects via the production of anthrax toxin (protective antigen, lethal factor and oedema factor); anthrax kills because the toxin overwhelms the patient before innate host defence systems have a chance to eradicate the invaders. Structural studies on these three components provide a starting point for the design of novel

Milton T Stubbs

2002-01-01

89

MICROBIOLOGY: A Binding Contract for Anthrax  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. As the anthrax bioterrorism attacks demonstrated last year, individuals infected with the causative organism, Bacillus anthracis, may still die even after successful antibiotic treatment because of the production of large amounts of the anthrax toxin. In their Perspective, Bull and Parrish discuss new work published elsewhere that identifies an antitoxin antibody that could be used to passively immunize infected individuals and neutralize the anthrax toxin.

James J. Bull (University of Texas;Section of Integrative Biology and Institute for Cellular and Molecular Biology); Colin R. Parrish (Cornell University;James A. Baker Institute, College of Veterinary Medicine)

2002-07-12

90

Cytotoxicity of the matrix metalloproteinase-activated anthrax lethal toxin is dependent on gelatinase expression and B-RAF status in human melanoma cells  

PubMed Central

Anthrax Lethal Toxin (LeTx) demonstrates potent MAPK pathway inhibition and apoptosis in melanoma cells that harbor the activating V600E B-RAF mutation. LeTx is composed of two proteins, PA and LF. Uptake of the toxin into cells is dependent upon proteolytic activation of PA by the ubiquitously expressed furin or furin-like proteases. In order to circumvent nonspecific LeTx activation, a substrate preferably cleaved by gelatinases was substituted for the furin LeTx activation site. Here we have shown the toxicity of this MMP-activated LeTx is dependent on host cell surface MMP-2 and ?9 activity as well as the presence of the activating V600E B-RAF mutation, making this toxin dual specific. This additional layer of tumor cell specificity would potentially decrease systemic toxicity from the reduction of nonspecific toxin activation while retaining anti-tumor efficacy in patients with V600E B-RAF melanomas. Moreover, our results indicate that cell surface-associated gelatinase expression can be used to predict sensitivity among V600E B-RAF melanomas. This finding will aid in the better selection of patients that will potentially respond to MMP-activated LeTx therapy. PMID:18483309

Alfano, Randall W.; Leppla, Stephen H.; Liu, Shihui; Bugge, Thomas H.; Herlyn, Meenhard; Smalley, Keiran S.; Bromberg-White, Jennifer L.; Duesbery, Nicholas S.; Frankel, Arthur E.

2009-01-01

91

Bacillus cereus G9241 Makes Anthrax Toxin and Capsule like Highly Virulent B. anthracis Ames but Behaves like Attenuated Toxigenic Nonencapsulated B. anthracis Sterne in Rabbits and Mice ?  

PubMed Central

Bacillus cereus G9241 was isolated from a welder with a pulmonary anthrax-like illness. The organism contains two megaplasmids, pBCXO1 and pBC218. These plasmids are analogous to the Bacillus anthracis Ames plasmids pXO1 and pXO2 that encode anthrax toxins and capsule, respectively. Here we evaluated the virulence of B. cereus G9241 as well as the contributions of pBCXO1 and pBC218 to virulence. B. cereus G9241 was avirulent in New Zealand rabbits after subcutaneous inoculation and attenuated 100-fold compared to the published 50% lethal dose (LD50) values for B. anthracis Ames after aerosol inoculation. A/J and C57BL/6J mice were comparably susceptible to B. cereus G9241 by both subcutaneous and intranasal routes of infection. However, the LD50s for B. cereus G9241 in both mouse strains were markedly higher than those reported for B. anthracis Ames and more like those of the toxigenic but nonencapsulated B. anthracis Sterne. Furthermore, B. cereus G9241 spores could germinate and disseminate after intranasal inoculation into A/J mice, as indicated by the presence of vegetative cells in the spleen and blood of animals 48 h after infection. Lastly, B. cereus G9241 derivatives cured of one or both megaplasmids were highly attenuated in A/J mice. We conclude that the presence of the toxin- and capsule-encoding plasmids pBCXO1 and pBC218 in B. cereus G9241 alone is insufficient to render the strain as virulent as B. anthracis Ames. However, like B. anthracis, full virulence of B. cereus G9241 for mice requires the presence of both plasmids. PMID:21576337

Wilson, Melissa K.; Vergis, James M.; Alem, Farhang; Palmer, John R.; Keane-Myers, Andrea M.; Brahmbhatt, Trupti N.; Ventura, Christy L.; O'Brien, Alison D.

2011-01-01

92

The Anthrax Toxin Activator Gene atxA Is Associated with CO2Enhanced Non-Toxin Gene Expression in Bacillus anthracis  

Microsoft Academic Search

tions from atxA1 and atxA isolates grown in 5% CO2 and in air were examined by two-dimensional electro- phoresis. Comparison of the resulting protein patterns indicated that synthesis of non-toxin proteins is influenced by growth in elevated CO2 and the toxin gene regulator, atxA. Second, we generated random transcriptional lacZ fusions in B. anthracis with transposon Tn917-LTV3. Transposon-insertion libraries were

ALEX R. HOFFMASTER; THERESA M. KOEHLER

1997-01-01

93

Effect of anthrax immune globulin on response to BioThrax (anthrax vaccine adsorbed) in New Zealand white rabbits.  

PubMed

Development of anthrax countermeasures that may be used concomitantly in a postexposure setting requires an understanding of the interaction between these products. Anthrax immune globulin intravenous (AIGIV) is a candidate immunotherapeutic that contains neutralizing antibodies against protective antigen (PA), a component of anthrax toxins. We evaluated the interaction between AIGIV and BioThrax (anthrax vaccine adsorbed) in rabbits. While pharmacokinetics of AIGIV were not altered by vaccination, the vaccine-induced immune response was abrogated in AIGIV-treated animals. PMID:23979740

Malkevich, Nina V; Basu, Subhendu; Rudge, Thomas L; Clement, Kristin H; Chakrabarti, Ajoy C; Aimes, Ronald T; Nabors, Gary S; Skiadopoulos, Mario H; Ionin, Boris

2013-11-01

94

Cellular adaptation to anthrax lethal toxin-induced mitochondrial cholesterol enrichment, hyperpolarization, and reactive oxygen species generation through downregulating MLN64 in macrophages.  

PubMed

Cellular adaptation to different stresses related to survival and function has been demonstrated in several cell types. Anthrax lethal toxin (LeTx) induces rapid cell death, termed "pyroptosis," by activating NLRP1b/caspase-1 in murine macrophages. We and others (S. D. Ha et al., J. Biol. Chem. 282:26275-26283, 2007; I. I. Salles et al., Proc. Natl. Acad. Sci. U. S. A. 100:12426 -12431, 2003) have shown that RAW264.7 cells preexposed to sublethal doses of LeTx become resistant to subsequent high cytolytic doses of LeTx, termed toxin-induced resistance (TIR). To date, the cellular mechanisms of pyroptosis and TIR are largely unknown. We found that LeTx caused NLRP1b/caspase-1-dependent mitochondrial dysfunction, including hyperpolarization and generation of reactive oxygen species, which was distinct from that induced by stimuli such as NLRP3-activating ATP. In TIR cells, these mitochondrial events were not detected, although caspase-1 was activated, in response to LeTx. We identified that downregulation of the late endosomal cholesterol-transferring protein MLN64 in TIR cells was involved in TIR. The downregulation of MLN64 in TIR cells was at least in part due to DNA methyltransferase 1-mediated DNA methylation. In wild-type RAW264.7 cells and primary bone marrow-derived macrophages, LeTx caused NLRP1b/caspase-1-dependent mitochondrial translocation of MLN64, resulting in cholesterol enrichment, membrane hyperpolarization, reactive oxygen species (ROS) generation, and depletion of free glutathione (GSH). This study demonstrates for the first time that MLN64 plays a key role in LeTx/caspase-1-induced mitochondrial dysfunction. PMID:23028046

Ha, Soon-Duck; Park, Sangwook; Han, Chae Young; Nguyen, Marilyn L; Kim, Sung Ouk

2012-12-01

95

Anthrax Lethal Toxin Impairs IL-8 Expression in Epithelial Cells through Inhibition of Histone H3 Modification  

E-print Network

are taken up by macrophages and/or dendritic cells, and subsequently migrate in the draining lymph nodes Abstract Lethal toxin (LT) is a critical virulence factor of Bacillus anthracis, the etiological agent, instillation of a B. anthracis strain expressing active LT represses lung inflammation. The inhibitory effects

Paris-Sud XI, Université de

96

Anthrax Attacks  

NSDL National Science Digital Library

This Science NetLinks lesson focuses on the bacterial disease known as Anthrax. Anthrax has always been identified as a disease that infects cattle, but there are known cases of people contracting this disease directly from handling infected cattle. In this online lesson the students will research the disease and its impact on human health.

Science Netlinks;

2002-05-05

97

Injection Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

98

Anthrax: Symptoms  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

99

Cutaneous Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

100

Anthrax: Treatment  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

101

Anthrax: Prevention  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

102

Anthrax: Diagnosis  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

103

Gastrointestinal Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

104

Inhalation Anthrax  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

105

Bioterrorism Preparedness--Anthrax  

E-print Network

This publication explains how people can prepare for a terrorist attack that uses anthrax. It discusses the reasons anthrax might be used in a bioterrorist attack and lists symptoms of anthrax infection in people and signs in animals....

Lawhorn, D. Bruce

2002-04-24

106

Anthrax - blood test  

MedlinePLUS

Anthrax serology test; Antibody test for anthrax; Serologic test for B. anthracis ... A normal result means no antibodies to the anthrax bacteria was seen in your blood sample. However, during the early stages of infection, your body may only ...

107

Scientists Report New Lead in How Anthrax Kills Cells  

Cancer.gov

For years scientists have known that anthrax bacillus produces a toxin containing a deadly protein called lethal factor. However, researchers have never been able to identify how lethal factor kills cells.

108

Assembly of the Small Outer Capsid Protein, Soc, on Bacteriophage T4: a novel system for high density display of multiple large anthrax toxins and foreign proteins on phage capsid  

PubMed Central

Summary Bacteriophage T4 capsid is a prolate icosahedron composed of the major capsid protein gp23*, the vertex protein gp24*, and the portal protein gp20. Assembled on its surface are 810 molecules of the non-essential small outer capsid protein, Soc (10 kDa), and 155 molecules of the highly antigenic outer capsid protein, Hoc (39 kDa). In this study Soc, a “triplex” protein that stabilizes T4 capsid, is targeted for molecular engineering of T4 particle surface. Using a defined in vitro assembly system, anthrax toxins, protective antigen, lethal factor and their domains, fused to Soc were efficiently displayed on the capsid. Both the N- and C-termini of the 80 amino acid Soc polypeptide can be simultaneously used to display antigens. Proteins as large as 93 kDa can be stably anchored on the capsid through Soc-capsid interactions. Using both Soc and Hoc, up to 1662 anthrax toxin molecules are assembled on phage T4 capsid under controlled conditions. We infer from the binding data that a relatively high affinity capsid binding site is located in the middle of the rod-shaped Soc, with the N- and C-termini facing the two- and three-fold symmetry axes of the capsid, respectively. Soc subunits interact at these interfaces, gluing the adjacent capsid protein hexamers and generating a cage-like outer scaffold. Antigen fusion does interfere with the inter-subunit interactions, but these interactions are not essential for capsid binding and antigen display. These features make the T4-Soc platform the most robust phage display system reported to date. The study offers insights into the architectural design of bacteriophage T4 virion, one of the most stable viruses known, and how its capsid surface can be engineered for novel applications in basic molecular biology and biotechnology. PMID:17544446

Li, Qin; Shivachandra, Sathish B.; Zhang, Zhihong; Rao, Venigalla B.

2007-01-01

109

Inhalational anthrax  

Microsoft Academic Search

Until recently, inhalational anthrax was a medical curiosity in both the Western medical literature and clinical practice.\\u000a The post-September 11, 2001 outbreak of this disease in the eastern United States that spread through the mail, however, instantly\\u000a changed the appreciation of this disease and the appreciation of biological terrorism\\/warfare in general. The microbiology,\\u000a epidemiology, clinical, and therapeutic\\/ preventative aspects of

Erwin Kurt Cullamar; Larry I. Lutwick

2002-01-01

110

An overview of anthrax infection including the recently identified form of disease in injection drug users  

PubMed Central

Purpose Bacillus anthracis infection (anthrax) can be highly lethal. Two recent outbreaks related to contaminated mail in the USA and heroin in the UK and Europe and its potential as a bioterrorist weapon have greatly increased concerns over anthrax in the developed world. Methods This review summarizes the microbiology, pathogenesis, diagnosis, and management of anthrax. Results and conclusions Anthrax, a gram-positive bacterium, has typically been associated with three forms of infection: cutaneous, gastrointestinal, and inhalational. However, the anthrax outbreak among injection drug users has emphasized the importance of what is now considered a fourth disease form (i.e., injectional anthrax) that is characterized by severe soft tissue infection. While cutaneous anthrax is most common, its early stages are distinct and prompt appropriate treatment commonly produces a good outcome. However, early symptoms with the other three disease forms can be nonspecific and mistaken for less lethal conditions. As a result, patients with gastrointestinal, inhalational, or injectional anthrax may have advanced infection at presentation that can be highly lethal. Once anthrax is suspected, the diagnosis can usually be made with gram stain and culture from blood or tissue followed by confirmatory testing (e.g., PCR). While antibiotics are the mainstay of anthrax treatment, use of adjunctive therapies such as anthrax toxin antagonists are a consideration. Prompt surgical therapy appears to be important for successful management of injectional anthrax. PMID:22527064

Hicks, Caitlin W.; Sweeney, Daniel A.; Cui, Xizhong; Li, Yan

2012-01-01

111

Serology and anthrax in humans, livestock and Etosha National Park wildlife.  

PubMed Central

Results are presented from a number of epidemiological studies using enzyme immunoassays (EIA) based on the purified anthrax toxin antigens, protective antigen, lethal factor and oedema factor. Studies on sera from a group of 62 human anthrax patients in Turkey and from cattle in Britain following two unrelated outbreaks of anthrax show that EIA using protective antigen can be a useful diagnostic aid and will detect subclinical infections in appropriate circumstances. A serological survey on wildlife in the Etosha National Park, Namibia, where anthrax is endemic, showed that naturally acquired anthrax-specific antibodies are rare in herbivores but common in carnivores; in carnivores, titres appear to reflect the prevalence of anthrax in their ranges. Problems, as yet unresolved, were encountered in studies on sera from pigs following an outbreak of anthrax on a farm in Wales. Clinical details, including treatment, of the human and one of the bovine outbreaks are summarized and discussed in relation to the serological findings. PMID:1582472

Turnbull, P. C.; Doganay, M.; Lindeque, P. M.; Aygen, B.; McLaughlin, J.

1992-01-01

112

Anthrax toxin protective antigen integrates poly-?-d-glutamate and pH signals to sense the optimal environment for channel formation  

PubMed Central

Many toxins assemble into oligomers on the surface of cells. Local chemical cues signal and trigger critical rearrangements of the oligomer, inducing the formation of a membrane-fused or channel state. Bacillus anthracis secretes two virulence factors: a tripartite toxin and a poly-?-d-glutamic acid capsule (?-DPGA). The toxin’s channel-forming component, protective antigen (PA), oligomerizes to create a prechannel that forms toxic complexes upon binding the two other enzyme components, lethal factor (LF) and edema factor (EF). Following endocytosis into host cells, acidic pH signals the prechannel to form the channel state, which translocates LF and EF into the host cytosol. We report ?-DPGA binds to PA, LF, and EF, exhibiting nanomolar avidity for the PA prechannel oligomer. We show PA channel formation requires the pH-dependent disruption of the intra-PA domain-2–domain-4 (D2-D4) interface. ?-DPGA stabilizes the D2-D4 interface, preventing channel formation both in model membranes and cultured mammalian cells. A 1.9-Å resolution X-ray crystal structure of a D2-D4-interface mutant and corresponding functional studies reveal how stability at the intra-PA interface governs channel formation. We also pinpoint the kinetic pH trigger for channel formation to a residue within PA’s membrane-insertion loop at the inter-PA D2-D4 interface. Thus, ?-DPGA may function as a chemical cue, signaling that the local environment is appropriate for toxin assembly but inappropriate for channel formation. PMID:23100533

Kintzer, Alexander F.; Tang, Iok I; Schawel, Adam K.; Brown, Michael J.; Krantz, Bryan A.

2012-01-01

113

Anthrax capsule vaccine protects against experimental infection.  

PubMed

Efficacy of a poly-gamma-D-glutamic acid anthrax capsule vaccine was assessed in a mouse model of infection. Capsule by itself was protective against lethal challenge with a toxin(-), capsule(+) Bacillus anthracis strain. Conjugation of capsule to bovine serum albumin resulted in enhanced IgG anti-capsule antibodies measured by ELISA, but completely abrogated the protection. The protective unconjugated capsule vaccine elicited significantly higher IgM titers and opsonic activity than did the non-protective capsule conjugate. When tested against a fully virulent toxin(+), capsule(+) B. anthracis strain, neither capsule nor protective antigen alone was protective. However, the combination of the two protected against a lethal challenge. These results suggest that capsule may enhance the protection afforded by protective antigen vaccines against anthrax if opsonizing antibodies are produced. Surprisingly, some protection was also observed when protective antigen was conjugated to itself. PMID:15519706

Chabot, Donald J; Scorpio, Angelo; Tobery, Steven A; Little, Stephen F; Norris, Sarah L; Friedlander, Arthur M

2004-11-15

114

Anthrax: an update  

PubMed Central

Anthrax is a zoonotic disease caused by Bacillus anthracis. It is potentially fatal and highly contagious disease. Herbivores are the natural host. Human acquire the disease incidentally by contact with infected animal or animal products. In the 18th century an epidemic destroyed approximately half of the sheep in Europe. In 1900 human inhalational anthrax occured sporadically in the United States. In 1979 an outbreak of human anthrax occured in Sverdlovsk of Soviet Union. Anthrax continued to represent a world wide presence. The incidence of the disease has decreased in developed countries as a result of vaccination and improved industrial hygiene. Human anthrax clinically presents in three forms, i.e. cutaneous, gastrointestinal and inhalational. About 95% of human anthrax is cutaneous and 5% is inhalational. Gastrointestinal anthrax is very rare (less than 1%). Inhalational form is used as a biological warefare agent. Penicillin, ciprofloxacin (and other quinolones), doxicyclin, ampicillin, imipenem, clindamycin, clarithromycin, vancomycin, chloramphenicol, rifampicin are effective antimicrobials. Antimicrobial therapy for 60 days is recommended. Human anthrax vaccine is available. Administration of anti-protective antigen (PA) antibody in combination with ciprofloxacin produced 90%-100% survival. The combination of CPG-adjuvanted anthrax vaccine adsorbed (AVA) plus dalbavancin significantly improved survival. PMID:23569822

Kamal, SM; Rashid, AKM M; Bakar, MA; Ahad, MA

2011-01-01

115

A comparison of non-toxin vaccine adjuvants for their ability to enhance the immunogenicity of nasally-administered anthrax recombinant protective antigen  

PubMed Central

Development of nasal immunization for human use is hindered by the lack of acceptable adjuvants. Although CT is an effective adjuvant, its toxicity will likely prevent its use in nasal vaccines. This study compared non-toxin adjuvants to CT for their ability to induce protective antibody responses with nasal immunization. C3H/HeN and C57BL/6 mice were immunized with rPA formulated with the following adjuvants: CT, IL-1?, LPS, CpG, Pam3CSK4, 3M-019, resiquimod/R848 or c48/80. Serum and nasal wash cytokine concentrations were monitored 6 hours post-vaccination as biomarkers for acute activation of the innate immune system. Not all of the adjuvants induced significant changes in innate serum or nasal wash cytokines, but when changes were observed, the cytokine signatures were unique for each adjuvant. All adjuvants except Pam3CSK4 induced significantly increased anti-rPA serum IgG titers in both strains of mice, while only IL-1?, c48/80 and CpG enhanced mucosal anti-rPA IgA. Pam3CSK4 was the only adjuvant unable to enhance the induction of serum LeTx-neutralizing antibodies in C3H/HeN mice while c48/80 was the only adjuvant to induce increased serum LeTx-neutralizing antibodies in C57BL/6 mice. Only CT enhanced total serum IgE in C3H/HeN mice while IL-1? enhanced total serum IgE in C57BL/6 mice. The adjuvant influenced antigen-specific serum IgG subclass and T cell cytokine profiles, but these responses did not correlate with the induction of LeTx-neutralizing activity. Our results demonstrate the induction of diverse innate and adaptive immune responses by non-toxin nasal vaccine adjuvants that lead to protective humoral immunity comparable to CT and that these responses may be influenced by the host strain. PMID:23352329

Gwinn, William M.; Johnson, Brandi T.; Kirwan, Shaun M.; Sobel, Ashley E.; Abraham, Soman N.; Gunn, Michael D.; Staats, Herman F.

2013-01-01

116

Molecular Motions as a Drug Target: Mechanistic Simulations of Anthrax Toxin Edema Factor Function Led to the Discovery of Novel Allosteric Inhibitors  

PubMed Central

Edema Factor (EF) is a component of Bacillus anthracis toxin essential for virulence. Its adenylyl cyclase activity is induced by complexation with the ubiquitous eukaryotic cellular protein, calmodulin (CaM). EF and its complexes with CaM, nucleotides and/or ions, have been extensively characterized by X-ray crystallography. Those structural data allowed molecular simulations analysis of various aspects of EF action mechanism, including the delineation of EF and CaM domains through their association energetics, the impact of calcium binding on CaM, and the role of catalytic site ions. Furthermore, a transition path connecting the free inactive form to the CaM-complexed active form of EF was built to model the activation mechanism in an attempt to define an inhibition strategy. The cavities at the surface of EF were determined for each path intermediate to identify potential sites where the binding of a ligand could block activation. A non-catalytic cavity (allosteric) was found to shrink rapidly at early stages of the path and was chosen to perform virtual screening. Amongst 18 compounds selected in silico and tested in an enzymatic assay, 6 thiophen ureidoacid derivatives formed a new family of EF allosteric inhibitors with IC50 as low as 2 micromolars. PMID:23012649

Laine, Elodie; Martinez, Leandro; Ladant, Daniel; Malliavin, Therese; Blondel, Arnaud

2012-01-01

117

Anthrax Lethal Toxin Impairs CD1d-Mediated Antigen Presentation by Targeting the Extracellular Signal-Related Kinase 1/2 Mitogen-Activated Protein Kinase Pathway?  

PubMed Central

Lethal toxin (LT) is a critical virulence factor of Bacillus anthracis and an important means by which this bacterium evades the host's immune system. In this study, we demonstrate that CD1d-expressing cells treated with LT have reduced CD1d-mediated antigen presentation. We earlier showed an important role for the mitogen-activated protein kinase extracellular signal-regulated kinase 1/2 (ERK1/2) in the regulation of CD1d-mediated antigen presentation, and we report here that LT impairs antigen presentation by CD1d in an ERK1/2-dependent manner. Similarly, LT and the ERK1/2 pathway-specific inhibitor U0126 caused a decrease in major histocompatibility complex (MHC) class II-mediated antigen presentation. Confocal microscopy analyses revealed altered intracellular distribution of CD1d and LAMP-1 in LT-treated cells, similar to the case for ERK1/2-inhibited cells. These results suggest that Bacillus anthracis has the ability to evade the host's innate immune system by reducing CD1d-mediated antigen presentation through targeting the ERK1/2 pathway. PMID:20194602

Khan, Masood A.; Gallo, Richard M.; Brutkiewicz, Randy R.

2010-01-01

118

Researchers Compare Anthrax Genomes  

NSF Publications Database

... as a tool for the forensic analysis of microbes, scientists at The Institute for Genomic Research ... differences among nearly identical strains of microbes such as anthrax. Previous genetic marker ...

119

Anthrax undervalued zoonosis  

Microsoft Academic Search

Anthrax is a non-contagious disease, known since ancient times. However, it became a matter of global public interest after the bioterrorist attacks in the U.S.A. during the autumn of 2001. The concern of politicians and civil authorities everywhere towards this emergency necessitated a significant research effort and the prevention of new bioterrorist acts. Anthrax is primarily a disease that affects

Antonio Fasanella; Domenico Galante; Giuliano Garofolo; Martin Hugh Jones

2010-01-01

120

Soluble expression and purification of the anthrax protective antigen in E. coli and identification of a novel dominant-negative mutant N435C  

Microsoft Academic Search

The anthrax toxin is an AB-type bacterium toxin composed of the protective antigen (PA) as the cell-binding B component, and\\u000a the lethal factor (LF) and edema toxin (EF) as the catalytic A components. The PA component is a key factor in anthrax-related\\u000a research and recombinant PA can be produced in general in Escherichia coli. However, such recombinant PA always forms

Gaobing Wu; Chunfang Feng; Yuzhi Hong; Aizhen Guo; Sha Cao; Junli Dong; Ling Lin; Ziduo Liu

2010-01-01

121

Efficacy of a Vaccine Based on Protective Antigen and Killed Spores against Experimental Inhalational Anthrax  

Microsoft Academic Search

Protective antigen (PA)-based anthrax vaccines acting on toxins are less effective than live attenuated vaccines, suggesting that additional antigens may contribute to protective immunity. Several reports indicate that capsule or spore-associated antigens may enhance the protection afforded by PA. Addition of formalde- hyde-inactivated spores (FIS) to PA (PA-FIS) elicits total protection against cutaneous anthrax. Nevertheless, vaccines that are effective against

Yves P. Gauthier; Jean-Nicolas Tournier; Jean-Charles Paucod; Jean-Philippe Corre; Michele Mock; Pierre L. Goossens; Dominique R. Vidal

2009-01-01

122

Characterization of the human immune response to the UK anthrax vaccine  

Microsoft Academic Search

The anthrax bipartite lethal toxin (protective antigen (PA) and lethal factor (LF))-specific antibody responses of humans receiving the UK licensed anthrax vaccine were determined. The PA-specific IgG response peaked two weeks post immunization and fell back to pre-boost levels by week 12. The heterogeneity of the host population modulated the extent of the PA-specific antibody response. Significantly lower levels of

Les Baillie; Tim Townend; Nicki Walker; Ulla Eriksson; Diane Williamson

2004-01-01

123

Designing a polyvalent inhibitor of anthrax toxin  

Microsoft Academic Search

Screening peptide libraries is a proven strategy for identifying inhibitors of protein–ligand interactions. Compounds identified in these screens often bind to their targets with low affinities. When the target protein is present at a high density on the surface of cells or other biological surfaces, it is sometimes possible to increase the biological activity of a weakly binding ligand by

Michael Mourez; Ravi S. Kane; Jeremy Mogridge; Steve Metallo; Pascal Deschatelets; Bret R. Sellman; George M. Whitesides; R. John Collier

2001-01-01

124

Marked enhancement of the immune response to BioThrax ® (Anthrax Vaccine Adsorbed) by the TLR9 agonist CPG 7909 in healthy volunteers  

Microsoft Academic Search

Immunization with BioThrax® (Anthrax Vaccine Adsorbed) is a safe and effective means of preventing anthrax. Animal studies have demonstrated that the addition of CpG DNA adjuvants to BioThrax can markedly increase the immunogenicity of the vaccine, increasing both serum anti-protective antigen (PA) antibody and anthrax toxin-neutralizing antibody (TNA) concentrations. The immune response to CpG-adjuvanted BioThrax in animals was not only

Dianna Rynkiewicz; Melinda Rathkopf; Iain Sim; A. Thomas Waytes; Robert J. Hopkins; Lallan Giri; Deborah DeMuria; Janet Ransom; James Quinn; Gary S. Nabors; Carl J. Nielsen

2011-01-01

125

Evaluation of intravenous anthrax immune globulin for treatment of inhalation anthrax.  

PubMed

Bacillus anthracis toxins can be neutralized by antibodies against protective antigen (PA), a component of anthrax toxins. Anthrivig (human anthrax immunoglobulin), also known as AIGIV, derived from plasma of humans immunized with BioThrax (anthrax vaccine adsorbed), is under development for the treatment of toxemia following exposure to anthrax spores. The pharmacokinetics (PK) of AIGIV was assessed in naive animals and healthy human volunteers, and the efficacy of AIGIV was assessed in animals exposed via inhalation to aerosolized B. anthracis spores. In the clinical study, safety, tolerability, and PK were evaluated in three dose cohorts (3.5, 7.1, and 14.2 mg/kg of body weight of anti-PA IgG) with 30 volunteers per cohort. The elimination half-life of AIGIV in rabbits, nonhuman primates (NHPs), and humans following intravenous infusion was estimated to be approximately 4, 12, and 24 days, respectively, and dose proportionality was observed. In a time-based treatment study, AIGIV protected 89 to 100% of animals when administered 12 h postexposure; however, a lower survival rate of 39% was observed when animals were treated 24 h postexposure, underscoring the need for early intervention. In a separate set of studies, animals were treated on an individual basis upon detection of a clinical sign or biomarker of disease, namely, a significant increase in body temperature (SIBT) in rabbits and presence of PA in the serum of NHPs. In these trigger-based intervention studies, AIGIV induced up to 75% survival in rabbits depending on the dose and severity of toxemia at the time of treatment. In NHPs, up to 33% survival was observed in AIGIV-treated animals. (The clinical study has been registered at ClinicalTrials.gov under registration no. NCT00845650.). PMID:23979731

Mytle, Nutan; Hopkins, Robert J; Malkevich, Nina V; Basu, Subhendu; Meister, Gabriel T; Sanford, Daniel C; Comer, Jason E; Van Zandt, Kristopher E; Al-Ibrahim, Mohamed; Kramer, William G; Howard, Cris; Daczkowski, Nancy; Chakrabarti, Ajoy C; Ionin, Boris; Nabors, Gary S; Skiadopoulos, Mario H

2013-11-01

126

Evaluation of Intravenous Anthrax Immune Globulin for Treatment of Inhalation Anthrax  

PubMed Central

Bacillus anthracis toxins can be neutralized by antibodies against protective antigen (PA), a component of anthrax toxins. Anthrivig (human anthrax immunoglobulin), also known as AIGIV, derived from plasma of humans immunized with BioThrax (anthrax vaccine adsorbed), is under development for the treatment of toxemia following exposure to anthrax spores. The pharmacokinetics (PK) of AIGIV was assessed in naive animals and healthy human volunteers, and the efficacy of AIGIV was assessed in animals exposed via inhalation to aerosolized B. anthracis spores. In the clinical study, safety, tolerability, and PK were evaluated in three dose cohorts (3.5, 7.1, and 14.2 mg/kg of body weight of anti-PA IgG) with 30 volunteers per cohort. The elimination half-life of AIGIV in rabbits, nonhuman primates (NHPs), and humans following intravenous infusion was estimated to be approximately 4, 12, and 24 days, respectively, and dose proportionality was observed. In a time-based treatment study, AIGIV protected 89 to 100% of animals when administered 12 h postexposure; however, a lower survival rate of 39% was observed when animals were treated 24 h postexposure, underscoring the need for early intervention. In a separate set of studies, animals were treated on an individual basis upon detection of a clinical sign or biomarker of disease, namely, a significant increase in body temperature (SIBT) in rabbits and presence of PA in the serum of NHPs. In these trigger-based intervention studies, AIGIV induced up to 75% survival in rabbits depending on the dose and severity of toxemia at the time of treatment. In NHPs, up to 33% survival was observed in AIGIV-treated animals. (The clinical study has been registered at ClinicalTrials.gov under registration no. NCT00845650.) PMID:23979731

Mytle, Nutan; Hopkins, Robert J.; Malkevich, Nina V.; Basu, Subhendu; Meister, Gabriel T.; Sanford, Daniel C.; Comer, Jason E.; Van Zandt, Kristopher E.; Al-Ibrahim, Mohamed; Kramer, William G.; Howard, Cris; Daczkowski, Nancy; Chakrabarti, Ajoy C.; Ionin, Boris; Nabors, Gary S.

2013-01-01

127

What Is Anthrax?  

MedlinePLUS

... SIL-us an-THRAY-sus). These bacteria make spores , a form of the germ covered by a protective shell. The spores can live for years in the soil, and ... get anthrax if they are exposed to the spores. (Exposed means that a germ that can cause ...

128

Radiolabeled Phenethylguanidines  

PubMed Central

The norepinephrine transporter (NET) substrates [123I]meta-iodobenzylguanidine (MIBG) and [11C]meta-hydroxyephedrine (HED) are used as markers of cardiac sympathetic neurons and adrenergic tumors (pheochromocytoma, neuroblastoma). However, their rapid NET transport rates limit their ability to provide accurate measurements of cardiac nerve density. [11C]Phenethylguanidine ([11C]1a) and 12 analogs ([11C]1b-m) were synthesized and evaluated as radiotracers with improved kinetics for quantifying cardiac nerve density. In isolated rat hearts, neuronal uptake rates of [11C]1a-m ranged from 0.24 to 1.96 mL/min/g wet, and six compounds had extremely long neuronal retention times (clearance T1/2 > 20 hr) due to efficient vesicular storage. PET studies in nonhuman primates with [11C]1e, N-[11C]guanyl-meta-octopamine, which has a slow NET transport rate, showed improved myocardial kinetics compared to HED. Compound [11C]1c, [11C]para-hydroxyphenethylguandine, which has a rapid NET transport rate, avidly accumulated into rat pheochromocytoma xenograft tumors in mice. These encouraging findings demonstrate that radiolabeled phenethylguanidines deserve further investigation as radiotracers of cardiac sympathetic innervation and adrenergic tumors. PMID:17419605

Raffel, David M.; Jung, Yong-Woon; Gildersleeve, David L.; Sherman, Phillip S.; Moskwa, James J.; Tluczek, Louis J.; Chen, Wei

2008-01-01

129

Methods for neutralizing anthrax or anthrax spores  

DOEpatents

The present invention concerns methods, compositions and apparatus for neutralizing bioagents, wherein bioagents comprise biowarfare agents, biohazardous agents, biological agents and/or infectious agents. The methods comprise exposing the bioagent to an organic semiconductor and exposing the bioagent and organic semiconductor to a source of energy. Although any source of energy is contemplated, in some embodiments the energy comprises visible light, ultraviolet, infrared, radiofrequency, microwave, laser radiation, pulsed corona discharge or electron beam radiation. Exemplary organic semiconductors include DAT and DALM. In certain embodiments, the organic semiconductor may be attached to one or more binding moieties, such as an antibody, antibody fragment, or nucleic acid ligand. Preferably, the binding moiety has a binding affinity for one or more bioagents to be neutralized. Other embodiments concern an apparatus comprising an organic semiconductor and an energy source. In preferred embodiments, the methods, compositions and apparatus are used for neutralizing anthrax spores.

Sloan, Mark A; Vivekandanda, Jeevalatha; Holwitt, Eric A; Kiel, Johnathan L

2013-02-26

130

Pediatric anthrax clinical management.  

PubMed

Anthrax is a zoonotic disease caused by Bacillus anthracis, which has multiple routes of infection in humans, manifesting in different initial presentations of disease. Because B anthracis has the potential to be used as a biological weapon and can rapidly progress to systemic anthrax with high mortality in those who are exposed and untreated, clinical guidance that can be quickly implemented must be in place before any intentional release of the agent. This document provides clinical guidance for the prophylaxis and treatment of neonates, infants, children, adolescents, and young adults up to the age of 21 (referred to as "children") in the event of a deliberate B anthracis release and offers guidance in areas where the unique characteristics of children dictate a different clinical recommendation from adults. PMID:24777226

Bradley, John S; Peacock, Georgina; Krug, Steven E; Bower, William A; Cohn, Amanda C; Meaney-Delman, Dana; Pavia, Andrew T

2014-05-01

131

Dr. Jekyll and Mr. Hyde: a short history of anthrax.  

PubMed

The anthrax letters crisis, following the discovery of a major bacterial warfare program in the USSR and the realization that Irak had been on the verge of using anthrax as a weapon during the first Gulf war, had the consequence of putting anthrax back on the agenda of scientists. Fortunately, although it was mostly unknown by the public before these events, it was far from unknown by microbiologists. Already mentioned in the bible as a disease of herbivores, it remained a major cause of death for animals all over the planet until the end of the 19th century, with occasional, sometimes extensive, contamination of human beings. The aetiological agent, Bacillus anthracis, was identified by French and German scientists in the 1860s and 1870s. This was the first time that a disease could be attributed to a specific microorganism. The discovery by Koch that this bacterium formed spores greatly contributed to the understanding of the disease epidemiology. Studies on the pathophysiology of anthrax led to the identification of two major virulence factors, the capsule, protecting the bacilli against phagocytosis, and a tripartite toxin. The latter consists of two toxins with a common component (protecting antigen, PA) that allows the binding to and penetration into cells of two enzymes, the oedema factor EF, a calmodulin dependent adenylate cyclase, and the lethal factor LF, a specific zinc metalloprotease. The primary targets of these toxins would seem to be cells of innate immunity that would otherwise impair multiplication of the bacilli. If detected early enough, B. anthracis infections can be stopped by using antibiotics such as ciprofloxacin. Infection of animals can be prevented by the administration of vaccines, the first of which was developed by Pasteur after an historical testing at Pouilly-le-Fort which marked the beginning of the science of vaccines. PMID:19577591

Schwartz, Maxime

2009-12-01

132

Immune Responses to Bacillus anthracis Protective Antigen in Patients with Bioterrorism?Related Cutaneous or Inhalation Anthrax  

Microsoft Academic Search

Anti-protective antigen (PA) immunoglobulin (Ig) G, toxin neutralization, and PA-specific IgG memory B cell responses were studied in patients with bioterrorism-related cutaneous or inhalation anthrax and in a patient with laboratory-acquired cutaneous anthrax. Responses were determined for 11 year after the onset of symptoms. Eleven days after the onset of symptoms (15 days after likely exposure), anti-PA IgG was detected

Vera Semenova; Han Li; Shane Crotty; Carolyn Greene; John Glidewell; Rafi Ahmed

2004-01-01

133

Anthrax: a systematic review of atypical presentations.  

PubMed

During the 2001 US anthrax attacks, mortality from inhalational anthrax was significantly lower than had been reported historically, which was attributed in part to early identification and timely treatment. During future attacks, clinicians will rely on published descriptions of the clinical features of inhalational anthrax to rapidly diagnose patients and institute appropriate treatment. Published descriptions of typical inhalation anthrax usually include patients presenting with cough, dyspnea, or chest pain and found to have abnormal lung examination results with pleural effusions or enlarged mediastinum. The purpose of this article is to evaluate whether atypical presentations of inhalational anthrax occur and to describe the features of these presentations. We define atypical presentations as those in patients with confirmed anthrax infection who do not have known cutaneous, gastrointestinal, or inhalational ports of entry. We reviewed the case reports of 42 patients with atypical anthrax (published between 1900 and 2004) that may have had an inhalational source of infection to evaluate whether their clinical presentations differed from the typical findings of inhalational anthrax. Patients with atypical anthrax were less likely to have cough, chest pain, or abnormal lung examination results than patients with typical inhalational anthrax (P<.05 for all comparisons). A previously published screening protocol for patients with suspected anthrax correctly identified 91% of patients with atypical presentations. We conclude that although uncommon, atypical presentations of inhalational anthrax likely occur. Timely diagnosis and treatment of patients with inhalational anthrax require clinical awareness of the full spectrum of signs and symptoms associated with inhalational anthrax. PMID:16857469

Holty, Jon-Erik C; Kim, Rebecca Y; Bravata, Dena M

2006-08-01

134

Anthrax: Who Is at Risk  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

135

From Structure to Solutions: The Role of Basic Research in Developing Anthrax Countermeasures  

PubMed Central

Dr. John Collier traced the discoveries that elucidated the structure and function of the anthrax toxin in his talk “Anthrax Toxin,” which was part of the Microbiology Graduate Program Seminar Series at Yale School of Medicine on February 23, 2012. Dr. Collier, Professor of Microbiology and Immunobiology at Harvard University, began by noting the advantages to studying anthrax pathogenesis in a biosafety level-1 lab. This designation does not merely facilitate his research, but also reflects a larger trend of basic research being leveraged to develop translational applications. Basic research on toxin structure has led to the development of a vaccine by Dr. Collier’s group. Next-generation prophylactics also may stem from recent discoveries uncovering a role for cellular cofactors that mediate toxin function. Finally, basic research into the toxin substructure has facilitated efforts to change the receptor tropism to target dysregulated cells for therapeutic purposes. The urgency around biodefense agents makes the choice of research priorities a salient issue. As such, this author submits that basic research occupies a unique and lucrative niche driving clinical applications. PMID:22737057

Hardiman, Camille A.

2012-01-01

136

Anthrax Vaccine and Public Health Policy  

PubMed Central

The Centers for Disease Control and Prevention has classified Bacillus anthracis, the causative organism of anthrax, as a category A potential bioterrorism agent. There are critical shortcomings in the US anthrax vaccine program. Rather than depending on the private sector, the government must assume direct production of anthrax vaccine. The development of a capacity capable of preemptive immunization of the public against anthrax should be considered. PMID:17901434

Weiss, Martin Meyer; Weiss, Peter D.; Weiss, Joseph B.

2007-01-01

137

Modeling the host response to inhalation anthrax  

Microsoft Academic Search

Inhalation anthrax, an often fatal infection, is initiated by endospores of the bacterium Bacillus anthracis, which are introduced into the lung. To better understand the pathogenesis of an inhalation anthrax infection, we propose a two-compartment mathematical model that takes into account the documented early events of such an infection. Anthrax spores, once inhaled, are readily taken up by alveolar phagocytes,

Judy Day; Avner Friedman; Larry S Schlesinger

2011-01-01

138

Anthrax in Eastern Turkey, 1992–2004  

PubMed Central

We investigated animal and human anthrax cases during a 13-year period in eastern Turkey. From 1992 to 2004, a total of 464 animal and 503 human anthrax cases were detected. Most cases occurred in summer. Anthrax remains a health problem in eastern Turkey, and preventive measures should be taken. PMID:16485484

Parlak, Mehmet; Tastan, Rustu; Dinler, Ufuk; Saglam, Yavuz S.; Ozyurek, Serhat F.

2005-01-01

139

Investigation of Inhalation Anthrax Case, United States  

PubMed Central

Inhalation anthrax occurred in a man who vacationed in 4 US states where anthrax is enzootic. Despite an extensive multi-agency investigation, the specific source was not detected, and no additional related human or animal cases were found. Although rare, inhalation anthrax can occur naturally in the United States. PMID:24447835

Blaney, David; Shadomy, Sean; Lehman, Mark; Pesik, Nicki; Tostenson, Samantha; Delaney, Lisa; Tiller, Rebekah; DeVries, Aaron; Gomez, Thomas; Sullivan, Maureen; Blackmore, Carina; Stanek, Danielle; Lynfield, Ruth

2014-01-01

140

Airing Out Anthrax  

NASA Technical Reports Server (NTRS)

The AiroCide TiO2 is an air-purifier that kills 93.3 percent of airborne pathogens that pass through it, including Bacillus anthraci, more commonly known as anthrax. It is essentially a spinoff of KES Science & Technology, Inc.'s Bio-KES system, a highly effective device used by the produce industry for ethylene gas removal to aid in preserving the freshness of fruits, vegetables, and flowers. The TiO2-based ethylene removal technology that is incorporated into the company's AiroCide TiO2 and Bio-KES products was first integrated into a pair of plant-growth chambers known as ASTROCULTURE(TM) and ADVANCED ASTROCULTURE(TM). Both chambers have housed commercial plant growth experiments in space on either the Space Shuttle or the International Space Station. The AiroCide TiO2 also has a proven record of destroying 98 percent of other airborne pathogens, such as microscopic dust mites, molds, and fungi. Moreover, the device is a verified killer of Influenza A (flu), E. coli, Staphylococcus aureas, Streptococcus pyogenes, and Mycoplasma pneumoniae, among many other harmful viruses.

2002-01-01

141

A Viral Nanoparticle with Dual Function as an Anthrax Antitoxin and Vaccine  

PubMed Central

The recent use of Bacillus anthracis as a bioweapon has stimulated the search for novel antitoxins and vaccines that act rapidly and with minimal adverse effects. B. anthracis produces an AB-type toxin composed of the receptor-binding moiety protective antigen (PA) and the enzymatic moieties edema factor and lethal factor. PA is a key target for both antitoxin and vaccine development. We used the icosahedral insect virus Flock House virus as a platform to display 180 copies of the high affinity, PA-binding von Willebrand A domain of the ANTXR2 cellular receptor. The chimeric virus-like particles (VLPs) correctly displayed the receptor von Willebrand A domain on their surface and inhibited lethal toxin action in in vitro and in vivo models of anthrax intoxication. Moreover, VLPs complexed with PA elicited a potent toxin-neutralizing antibody response that protected rats from anthrax lethal toxin challenge after a single immunization without adjuvant. This recombinant VLP platform represents a novel and highly effective, dually-acting reagent for treatment and protection against anthrax. PMID:17922572

Manayani, Darly J; Thomas, Diane; Dryden, Kelly A; Reddy, Vijay; Siladi, Marc E; Marlett, John M; Rainey, G. Jonah A; Pique, Michael E; Scobie, Heather M; Yeager, Mark; Young, John A. T; Manchester, Marianne; Schneemann, Anette

2007-01-01

142

Inflammasome Sensor Nlrp1b-Dependent Resistance to Anthrax Is Mediated by Caspase1, IL1 Signaling and Neutrophil Recruitment  

Microsoft Academic Search

Bacillus anthracis infects hosts as a spore, germinates, and disseminates in its vegetative form. Production of anthrax lethal and edema toxins following bacterial outgrowth results in host death. Macrophages of inbred mouse strains are either sensitive or resistant to lethal toxin depending on whether they express the lethal toxin responsive or non-responsive alleles of the inflammasome sensor Nlrp1b (Nlrp1bS\\/S or

Mahtab Moayeri; Devorah Crown; Zachary L. Newman; Shu Okugawa; Michael Eckhaus; Christophe Cataisson; Shihui Liu; Inka Sastalla; Stephen H. Leppla

2010-01-01

143

Anthrax in animals and humans in Mongolia.  

PubMed

Anthrax is endemic throughout Mongolia, except in the semi-desert and desert areas of the south. The prevalence of anthrax in Mongolia had drastically decreased since the 1950s due to the use of anthrax antiserum and vaccines, but the privatisation of the animal husbandry sector and changes in the structures of the veterinary and medical delivery systems in Mongolia over the last decade have resulted in challenges for disease control. Animal and human anthrax has become an increasing problem since the mid-1990s. Human cutaneous anthrax is common in Mongolia as a result of exposure to infected animals. In this paper, the authors identify potential causes forthe increase of anthrax in Mongolia. The current prevention efforts may not be adequate. Anthrax surveillance and control must be intensified, particularly in areas of high prevalence. PMID:18293618

Odontsetseg, N; Sh, Tserendorj; Adiyasuren, Z; Uuganbayar, D; Mweene, A S

2007-12-01

144

9 CFR 113.66 - Anthrax Spore Vaccine-Nonencapsulated.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Anthrax Spore Vaccine-Nonencapsulated. 113.66 Section 113...VECTORS STANDARD REQUIREMENTS Live Bacterial Vaccines § 113.66 Anthrax Spore Vaccine—Nonencapsulated. Anthrax Spore...

2011-01-01

145

Microneedle-Based Intradermal Delivery of the Anthrax Recombinant Protective Antigen Vaccine  

Microsoft Academic Search

The recombinant protective antigen (rPA) of Bacillus anthracis is a promising anthrax vaccine. We compared serum immunoglobulin G levels and toxin-neutralizing antibody titers in rabbits following delivery of various doses of vaccine by microneedle-based intradermal (i.d.) delivery or intramuscular (i.m.) injection using conventional needles. Intradermal delivery required less antigen to induce levels of antibody similar to those produced via i.m.

John A. Mikszta; John P. Dekker; Noel G. Harvey; Cheryl H. Dean; John M. Brittingham; Joanne Huang; Vincent J. Sullivan; Beverly Dyas; Chad J. Roy; Robert G. Ulrich

2006-01-01

146

Apoptosis and melanogenesis in human melanoma cells induced by anthrax lethal factor inactivation of mitogen-activated protein kinase kinase  

NASA Astrophysics Data System (ADS)

Lethal factor, the principal virulence factor of Bacillus anthracis, inhibits mitogen-activated protein kinase (MAPK) signaling by proteolytically cleaving MAPK kinases. Edema factor, another component of anthrax toxin, is an adenylate cyclase, which increases intracellular cAMP. Inhibition of MAPK signaling with either anthrax lethal toxin (LeTx) or small molecule MAPK kinase inhibitors triggers apoptosis in human melanoma cells. Normal melanocytes do not undergo apoptosis in response to MAPK inhibition but arrest in the G1 phase of the cell cycle. Importantly, in vivo treatment of human melanoma xenograft tumors in athymic nude mice with LeTx results in significant or complete tumor regression without apparent side effects, suggesting that inhibiting the MAPK signaling pathway may be a useful strategy for treating melanoma. Additionally, interrupting MAPK signaling with LeTx and elevating cAMP with anthrax edema toxin in both melanoma cells and melanocytes lead to dramatic melanin production, perhaps explaining the formation of blackened eschars in cutaneous anthrax.

Koo, Han-Mo; Vanbrocklin, Matt; McWilliams, Mary Jane; Leppla, Stephan H.; Duesbery, Nicholas S.; Vande Woude, George F.

2002-03-01

147

Preparedness for an anthrax attack.  

PubMed

Bacillus anthracis is a long-known bacterial organism with a uniquely stable spore stage. Its stability and the lethal disease which results when the spore is inhaled made it a favorite of state-sponsored biological weapons programs throughout the Cold War era. It is also believed to be high on the list of candidate microbial agents which could be used by terrorist groups or lone actors. Its unique characteristics make protection of humans, especially civilians, from an intentional biological attack very difficult. The author argues that an all-hazards/public health approach - which would also be needed for any natural or deliberate outbreak, no matter the agent - should serve as a foundation of preparation for the specific anthrax countermeasures. Because B. anthracis is a unique organism, specific countermeasures for anthrax detection, diagnostics, prophylaxis and therapy, should be developed in nations or regions where the threat of biological attack is believed to warrant such preparation. Other considerations for a nation interested in anthrax preparedness are discussed. PMID:19619577

Franz, David R

2009-12-01

148

Symmetry Requirements for Effective Blocking of Pore-Forming Toxins: Comparative Study with ?-, ?-, and ?-Cyclodextrin Derivatives ? †  

PubMed Central

We compared the abilities of structurally related cationic cyclodextrins to inhibit Bacillus anthracis lethal toxin and Staphylococcus aureus ?-hemolysin. We found that both ?- and ?-cyclodextrin derivatives effectively inhibited anthrax toxin action by blocking the transmembrane oligomeric pores formed by the protective antigen (PA) subunit of the toxin, whereas ?-cyclodextrins were ineffective. In contrast, ?-hemolysin was selectively blocked only by ?-cyclodextrin derivatives, demonstrating that both symmetry and size of the inhibitor and the pore are important. PMID:21555769

Yannakopoulou, Konstantina; Jicsinszky, Laszlo; Aggelidou, Crysie; Mourtzis, Nikolaos; Robinson, Tanisha M.; Yohannes, Adiamseged; Nestorovich, Ekaterina M.; Bezrukov, Sergey M.; Karginov, Vladimir A.

2011-01-01

149

WASTE DISPOSAL WORKSHOPS: ANTHRAX CONTAMINATED WASTE  

E-print Network

WASTE DISPOSAL WORKSHOPS: ANTHRAX CONTAMINATED WASTE January 2010 Prepared for the Interagency left intentionally blank.] #12;Prepared for the U.S. Department of Energy PNNL-SA-69994 under Contract DE-AC05-76RL01830 Waste Disposal Workshops: Anthrax-Contaminated Waste AM Lesperance JF Upton SL

150

Human Cutaneous Anthrax, Georgia 2010-2012  

PubMed Central

We assessed the occurrence of human cutaneous anthrax in Georgia during 2010–-2012 by examining demographic and spatial characteristics of reported cases. Reporting increased substantially, as did clustering of cases near urban centers. Control efforts, including education about anthrax and livestock vaccination, can be directed at areas of high risk. PMID:24447721

Kracalik, Ian; Malania, Lile; Tsertsvadze, Nikoloz; Manvelyan, Julietta; Bakanidze, Lela; Imnadze, Paata; Tsanava, Shota

2014-01-01

151

LIST OF CONTRACTORS TO SUPPORT ANTHRAX REMEDIATION  

E-print Network

LIST OF CONTRACTORS TO SUPPORT ANTHRAX REMEDIATION May 2010 Prepared for the Interagency Biological by the Northwest Regional Technology Center for Homeland Security List of Contractors to Support Anthrax or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness

152

Anthrax eradication in cyprus: An historical survey  

Microsoft Academic Search

In those countries where anthrax causes serious loss it is customary to vaccinate the more valuable livestock at risk, usually cattle. Otherwise anthrax is commonly regardedas a disease to live with, the longevity of the spores and often the presence of reservoir hosts making any other view unrealistic. However, in Cyprus a different situation existed. The disease caused heavy losses

R. W. Crowther; R. M. Gambles

1983-01-01

153

Mailborne transmission of anthrax: Modeling and implications  

Microsoft Academic Search

A mathematical model is developed to analyze the transmission of inhalational anthrax through the postal system by cross-contam- ination of mail. The model consists of state vectors describing the numbers of cross-contaminated letters generated, the numbers of anthrax spores on these letters, the numbers of resulting infections in recipients, and matrices of transition probabilities acting on these vectors. The model

Glenn F. Webb; Martin J. Blaser

2002-01-01

154

Treatment of Anthrax Disease Frequently Asked Questions  

SciTech Connect

This document provides a summary of Frequently Asked Questions (FAQs) on the treatment of anthrax disease caused by a wide-area release of Bacillus anthracis spores as an act bioterrorism. These FAQs are intended to provide the public health and medical community, as well as others, with guidance and communications to support the response and long-term recovery from an anthrax event.

Judd, Kathleen S.; Young, Joan E.; Lesperance, Ann M.; Malone, John D.

2010-05-14

155

Serum adenosine deaminase activity in cutaneous anthrax  

PubMed Central

Background Adenosine deaminase (ADA) activity has been discovered in several inflammatory conditions; however, there are no data associated with cutaneous anthrax. The aim of this study was to investigate serum ADA activity in patients with cutaneous anthrax. Material/Methods Sixteen patients with cutaneous anthrax and 17 healthy controls were enrolled. We measured ADA activity; peripheral blood leukocyte, lymphocyte, neutrophil, and monocyte counts; erythrocyte sedimentation rate; and C reactive protein levels. Results Serum ADA activity was significantly higher in patients with cutaneous anthrax than in the controls (p<0.001). A positive correlation was observed between ADA activity and lymphocyte counts (r=0.589, p=0.021) in the patient group. Conclusions This study suggests that serum ADA could be used as a biochemical marker in cutaneous anthrax. PMID:24997584

Sunnetcioglu, Mahmut; Karadas, Sevdegul; Aslan, Mehmet; Ceylan, Mehmet Resat; Demir, Halit; Oncu, Mehmet Resit; Karahocagil, Mustafa Kas?m; Sunnetcioglu, Aysel; Aypak, Cenk

2014-01-01

156

Purification and biophysical characterization of the core protease domain of anthrax lethal factor  

SciTech Connect

Anthrax lethal toxin (LeTx) stands for the major virulence factor of the anthrax disease. It comprises a 90 kDa highly specific metalloprotease, the anthrax lethal factor (LF). LF possesses a catalytic Zn{sup 2+} binding site and is highly specific against MAPK kinases, thus representing the most potent native biomolecule to alter and inactivate MKK [MAPK (mitogen-activated protein kinase) kinases] signalling pathways. Given the importance of the interaction between LF and substrate for the development of anti-anthrax agents as well as the potential treatment of nascent tumours, the analysis of the structure and dynamic properties of the LF catalytic site are essential to elucidate its enzymatic properties. Here we report the recombinant expression and purification of a C-terminal part of LF (LF{sub 672-776}) that harbours the enzyme's core protease domain. The biophysical characterization and backbone assignments ({sup 1}H, {sup 13}C, {sup 15}N) of the polypeptide revealed a stable, well folded structure even in the absence of Zn{sup 2+}, suitable for high resolution structural analysis by NMR.

Gkazonis, Petros V.; Dalkas, Georgios A.; Chasapis, Christos T. [Department of Pharmacy, University of Patras, GR-26504 Patras (Greece)] [Department of Pharmacy, University of Patras, GR-26504 Patras (Greece); Vlamis-Gardikas, Alexios [Department of Biochemistry, Foundation for Biomedical Research (BRFAA), Academy of Athens, GR-11527 Athens (Greece)] [Department of Biochemistry, Foundation for Biomedical Research (BRFAA), Academy of Athens, GR-11527 Athens (Greece); Bentrop, Detlef [Institute of Physiology II, University of Freiburg, D-79108 Freiburg (Germany)] [Institute of Physiology II, University of Freiburg, D-79108 Freiburg (Germany); Spyroulias, Georgios A., E-mail: G.A.Spyroulias@upatras.gr [Department of Pharmacy, University of Patras, GR-26504 Patras (Greece)

2010-06-04

157

Stable Dry Powder Formulation for Nasal Delivery of Anthrax Vaccine  

PubMed Central

There is a current biodefense interest in protection against Anthrax. Here we developed a new generation of stable and effective anthrax vaccine. We studied the immune response elicited by rPA delivered intranasally with a novel mucosal adjuvant, a mast cell activator Compound 48/80. The vaccine formulation was prepared in a powder form by spray-freeze-drying (SFD) under optimized conditions to produce particles with a target size of D50=25?m, suitable for delivery to the rabbit nasal cavity. Physicochemical properties of the powder vaccines were characterized to assess their delivery and storage potential. Structural stability of rPA was confirmed by CD and ATR-FTIR, while functional stability of rPA and C48/80 was monitored by cell-based assays. Animal study was performed using a unitdose powder device for direct nasal application. Results showed that C48/80 provided effective mucosal adjuvant activity in rabbits. Freshly prepared SFD powder vaccine formulations or powders stored for over two years at room temperature elicited significantly elevated serum PA-specific and lethal toxin neutralization antibody titers that were comparable to that induced by IM immunization with rPA. Nasal delivery of this vaccine formulation may be a viable alternative to the currently licensed vaccine, or an attractive vaccine platform for other mucosally transmitted diseases. PMID:21905034

Wang, Sheena H.; Kirwan, Shaun M.; Abraham, Soman N.; Staats, Herman F.; Hickey, Anthony J.

2013-01-01

158

Targeting HER2-positive cancer cells with receptor-redirected anthrax protective antigen  

PubMed Central

Targeted therapeutics have emerged in recent years as an attractive approach to treating various types of cancer. One approach is to modify a cytocidal protein toxin to direct its action to a specific population of cancer cells. We created a targeted toxin in which the receptor-binding and pore-forming moiety of anthrax toxin, termed Protective Antigen (PA), was modified to redirect its receptor specificity to HER2, a marker expressed at the surface of a significant fraction of breast and ovarian tumors. The resulting fusion protein (mPA-ZHER2) delivered cytocidal effectors specifically into HER2-positive tumor cells, including a trastuzumab-resistant line, causing death of the cells. No off-target killing of HER2-negative cells was observed, either with homogeneous populations or with mixtures of HER2-positive and HER2-negative cells. A mixture of mPA variants targeting different receptors mediated killing of cells bearing either receptor, without affecting cells devoid of these receptors. Anthrax toxin may serve as an effective platform for developing therapeutics to ablate cells bearing HER2 or other tumor-specific cell-surface markers. PMID:23290417

McCluskey, Andrew J.; Olive, Andrew J.; Starnbach, Michael N.; Collier, R. John

2012-01-01

159

Binding of ATP by pertussis toxin and isolated toxin subunits  

SciTech Connect

The binding of ATP to pertussis toxin and its components, the A subunit and B oligomer, was investigated. Whereas, radiolabeled ATP bound to the B oligomer and pertussis toxin, no binding to the A subunit was observed. The binding of ({sup 3}H)ATP to pertussis toxin and the B oligomer was inhibited by nucleotides. The relative effectiveness of the nucleotides was shown to be ATP > GTP > CTP > TTP for pertussis toxin and ATP > GTP > TTP > CTP for the B oligomer. Phosphate ions inhibited the binding of ({sup 3}H)ATP to pertussis toxin in a competitive manner; however, the presence of phosphate ions was essential for binding of ATP to the B oligomer. The toxin substrate, NAD, did not affect the binding of ({sup 3}H)ATP to pertussis toxin, although the glycoprotein fetuin significantly decreased binding. These results suggest that the binding site for ATP is located on the B oligomer and is distinct from the enzymatically active site but may be located near the eukaryotic receptor binding site.

Hausman, S.Z.; Manclark, C.R.; Burns, D.L. (Center for Biologics Evaluation and Research, Bethesda, MD (USA))

1990-07-03

160

Role of Visible Light-Activated Photocatalyst on the Reduction of Anthrax Spore-Induced Mortality in Mice  

PubMed Central

Background Photocatalysis of titanium dioxide (TiO2) substrates is primarily induced by ultraviolet light irradiation. Anion-doped TiO2 substrates were shown to exhibit photocatalytic activities under visible-light illumination, relative environmentally-friendly materials. Their anti-spore activity against Bacillus anthracis, however, remains to be investigated. We evaluated these visible-light activated photocatalysts on the reduction of anthrax spore-induced pathogenesis. Methodology/Principal Findings Standard plating method was used to determine the inactivation of anthrax spore by visible light-induced photocatalysis. Mouse models were further employed to investigate the suppressive effects of the photocatalysis on anthrax toxin- and spore-mediated mortality. We found that anti-spore activities of visible light illuminated nitrogen- or carbon-doped titania thin films significantly reduced viability of anthrax spores. Even though the spore-killing efficiency is only approximately 25%, our data indicate that spores from photocatalyzed groups but not untreated groups have a less survival rate after macrophage clearance. In addition, the photocatalysis could directly inactivate lethal toxin, the major virulence factor of B. anthracis. In agreement with these results, we found that the photocatalyzed spores have tenfold less potency to induce mortality in mice. These data suggest that the photocatalysis might injury the spores through inactivating spore components. Conclusion/Significance Photocatalysis induced injuries of the spores might be more important than direct killing of spores to reduce pathogenicity in the host. PMID:19132100

Huang, Hsin-Hsien; Wong, Ming-Show; Lin, Hung-Chi; Chang, Hsin-Hou

2009-01-01

161

Multicomponent anthrax toxin display and delivery using bacteriophage T4  

Microsoft Academic Search

We describe a multicomponent antigen display and delivery system using bacteriophage T4. Two dispensable outer capsid proteins, Hoc (highly antigenic outer capsid protein, 155 copies) and Soc (small outer capsid protein, 810 copies), decorate phage T4 capsid. These proteins bind to the symmetrically localized capsid sites, which appear following prohead assembly and expansion. We hypothesized that multiple antigens fused to

Sathish B. Shivachandra; Qin Li; Kristina K. Peachman; Gary R. Matyas; Stephen H. Leppla; Carl R. Alving; Mangala Rao; Venigalla B. Rao

2007-01-01

162

[Molecular aspects of anthrax pathogenesis].  

PubMed

A model of anthrax infection with the role determined for main pathogenicity factors of Bacillus anthracis exotoxin and capsule is presented. After spore phagocytosis by macrophages, synthesis of the main exotoxin component begins - a protective antigen that in oligomeric form disrupts phagosome membrane. This accelerates the transition of the pathogen from phagosome into the macrophage cytoplasm. Poly-D-glutamine capsule synthesized by the pathogen triggers the exit (exocytosis) of vegetative cells from macrophages and protects them from re-phagocytosis in lymphatic node lumen. The vegetative cells, that actively and freely replicate in lymphatic node, secret an exotoxin that disrupts endothelial septum between lymph and blood due to cytotoxic activity. As a result the vegetative cells get into blood and bacteremia develops. Pathogenetic pattern during anthrax (multiple hemorrhages in various organs etc.) is associated with local microcirculation disorders of various organs caused by the effect of bacterial exoproteases via activation of Willebrand factor. This results in a rapid local increase of microbial mass and consequent powerful cytotoxic effect of exotoxin on the tissue cells of the affected organ. Death of the infected organism takes place at the final stage of infec- tion due to toxic shock caused by the exotoxin. A reduction of body temperature takes place after death and the process of spore formation begins in the dead animal: capsule depolymerization, chain shortening, peptidoglycan cortex formation. Spores in this form are the prolonged source of infectious agent conservation and spread of infection in nature. PMID:25286538

2014-01-01

163

Anthrax Vaccine Induced Antibodies Provide Cross-Species Prediction of Survival to Aerosol Challenge  

PubMed Central

Because clinical trials to assess the efficacy of vaccines against anthrax are not ethical or feasible, licensure for new anthrax vaccines will likely involve the Food and Drug Administration’s “Animal Rule,” a set of regulations that allow approval of products based on efficacy data only in animals combined with immunogenicity and safety data in animals and humans. US government sponsored animal studies have shown anthrax vaccine efficacy in a variety of settings. We examined data from 21 of those studies to determine if an immunological bridge based on lethal toxin neutralization activity assay (TNA) can predict survival against an inhalation anthrax challenge within and across species and genera. The 21 studies were classified into 11 different settings, each of which had the same animal species, vaccine type and formulation, vaccination schedule, time of TNA measurement, and challenge time. Logistic regression models determined the contribution of vaccine dilution dose and TNA on prediction of survival. For most settings, logistic models using only TNA explained more than 75% of the survival effect of the models with dose additionally included. Cross species survival predictions using TNA were compared to the actual survival and shown to have good agreement (Cohen’s ? ranged from 0.55 to 0.78). In one study design, cynomolgus macaque data predicted 78.6% survival in rhesus macaques (actual survival 83.0%) and 72.6% in rabbits (actual survival, 64.6%). These data add support for the use of TNA as an immunological bridge between species to extrapolate data in animals to predict anthrax vaccine effectiveness in humans. PMID:22972844

Fay, Michael P.; Follmann, Dean A.; Lynn, Freyja; Schiffer, Jarad M.; Stark, Greg; Kohberge, Robert; Quinn, Conrad P.; Nuzum, Edwin O.

2013-01-01

164

Evaluation of Immunogenicity and Efficacy of Anthrax Vaccine Adsorbed for Postexposure Prophylaxis  

PubMed Central

Antimicrobials administered postexposure can reduce the incidence or progression of anthrax disease, but they do not protect against the disease resulting from the germination of spores that may remain in the body after cessation of the antimicrobial regimen. Such additional protection may be achieved by postexposure vaccination; however, no anthrax vaccine is licensed for postexposure prophylaxis (PEP). In a rabbit PEP study, animals were subjected to lethal challenge with aerosolized Bacillus anthracis spores and then were treated with levofloxacin with or without concomitant intramuscular (i.m.) vaccination with anthrax vaccine adsorbed (AVA) (BioThrax; Emergent BioDefense Operations Lansing LLC, Lansing, MI), administered twice, 1 week apart. A significant increase in survival rates was observed among vaccinated animals compared to those treated with antibiotic alone. In preexposure prophylaxis studies in rabbits and nonhuman primates (NHPs), animals received two i.m. vaccinations 1 month apart and were challenged with aerosolized anthrax spores at day 70. Prechallenge toxin-neutralizing antibody (TNA) titers correlated with animal survival postchallenge and provided the means for deriving an antibody titer associated with a specific probability of survival in animals. In a clinical immunogenicity study, 82% of the subjects met or exceeded the prechallenge TNA value that was associated with a 70% probability of survival in rabbits and 88% probability of survival in NHPs, which was estimated based on the results of animal preexposure prophylaxis studies. The animal data provide initial information on protective antibody levels for anthrax, as well as support previous findings regarding the ability of AVA to provide added protection to B. anthracis-infected animals compared to antimicrobial treatment alone. PMID:23658392

Ionin, Boris; Hopkins, Robert J.; Pleune, Brett; Sivko, Gloria S.; Reid, Frances M.; Clement, Kristin H.; Rudge, Thomas L.; Stark, Gregory V.; Innes, Alison; Sari, Suha; Guina, Tina; Howard, Cris; Smith, Jeffrey; Swoboda, M. Lisa; Vert-Wong, Ekaterina; Johnson, Virginia; Nabors, Gary S.

2013-01-01

165

Anthrax vaccines: present status and future prospects.  

PubMed

The management of anthrax remains a top priority among the biowarfare/bioterror agents. It was the Bacillus anthracis spore attack through the US mail system after the September 11, 2001, terrorist attacks in the USA that highlighted the potential of B. anthracis as a bioterrorism agent and the threat posed by its deliberate dissemination. These attacks invigorated the efforts toward understanding the anthrax pathogenesis and development of more comprehensive medical intervention strategies for its containment in case of both natural disease and manmade, accidental or deliberate infection of a non-suspecting population. Currently, efforts are directed toward the development of safe and efficacious vaccines as well as intervention tools for controlling the disease in the advanced fulminant stage when toxemia has already developed. This work presents an overview of the current understanding of anthrax pathogenesis and recent advances made, particularly after 2001, for the successful management of anthrax and outlines future perspectives. PMID:23984963

Kaur, Manpreet; Singh, Samer; Bhatnagar, Rakesh

2013-08-01

166

Anthrax: Exposure to Hides/Drums  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

167

Laboratory Testing for Anthrax: Frequently Asked Questions  

MedlinePLUS

... Confirming Anthrax Through the Laboratory Response Network Laboratory Testing - FAQs Collecting Specimens Recommended Specimens Information for Specific Groups Laboratory Professionals People Who Work with Animal Products Exposure to Hides/Drums Treatment of Products ...

168

Clinical application of radiolabelled platelets  

SciTech Connect

This book presents papers on the clinical applications of radiolabelled platelets. The papers are grouped into six sections on platelet labelling techniques, radiolabelled platelets in cardiology, monitoring of antiplatelet therapy, platelet scintigraphy in stroke patients, platelet scintigraphy in angiology, and platelet scintigraphy in hematology and other clinical applications, including renal transplant rejection.

Kessler, C. (Medical Univ. Lubeck, Lubeck (DE))

1990-01-01

169

Mapping the lethal factor and edema factor binding sites on oligomeric anthrax protective antigen  

PubMed Central

Assembly of anthrax toxin complexes at the mammalian cell surface involves competitive binding of the edema factor (EF) and lethal factor (LF) to heptameric oligomers and lower order intermediates of PA63, the activated carboxyl-terminal 63-kDa fragment of protective antigen (PA). We used sequence differences between PA63 and homologous PA-like proteins to delineate a region within domain 1? of PA that may represent the binding site for these ligands. Substitution of alanine for any of seven residues in or near this region (R178, K197, R200, P205, I207, I210, and K214) strongly inhibited ligand binding. Selected mutations from this set were introduced into two oligomerization-deficient PA mutants, and the mutants were used in various combinations to map the single ligand site within dimeric PA63. The site was found to span the interface between two adjacent subunits, explaining the dependence of ligand binding on PA oligomerization. The locations of residues comprising the site suggest that a single ligand molecule sterically occludes two adjacent sites, consistent with the finding that the PA63 heptamer binds a maximum of three ligand molecules. These results elucidate the process by which the components of anthrax toxin, and perhaps other binary bacterial toxins, assemble into toxic complexes. PMID:11997439

Cunningham, Kristina; Lacy, D. Borden; Mogridge, Jeremy; Collier, R. John

2002-01-01

170

FINANCIAL SUPPORT FOR THE PRIVATE SECTOR AFTER AN ANTHRAX BIOTERRORISM  

E-print Network

FINANCIAL SUPPORT FOR THE PRIVATE SECTOR AFTER AN ANTHRAX BIOTERRORISM INCIDENT September Bioterrorism Incident KS Judd AM Lesperance September 30, 2009 #12; DISCLAIMER This report was prepared; 1 FINANCIAL SUPPORT FOR THE PRIVATE SECTOR AFTER AN ANTHRAX BIOTERRORISM INCIDENT Through

171

Anthrax  

E-print Network

clostridial infections, bloat, lightning strike, acute lep- tospirosis, bacillary hemoglobinura, anaplasmosis, babesiosis, and acute poisoning by bracken fern, sweet clover, lead, or blue-green algae. In horses, acute equine infectious anemia, colic... clostridial infections, bloat, lightning strike, acute lep- tospirosis, bacillary hemoglobinura, anaplasmosis, babesiosis, and acute poisoning by bracken fern, sweet clover, lead, or blue-green algae. In horses, acute equine infectious anemia, colic...

Lawhorn, D. Bruce

2001-08-09

172

Anthrax  

MedlinePLUS

... potential to be used as a weapon of bioterrorism; this occurred in 2001 with an attack on ... Animal shearers Tanners In the case of a bioterrorism attack, anyone exposed to B. anthracis is at ...

173

Emergency response to an anthrax attack Lawrence M. Wein*  

E-print Network

Emergency response to an anthrax attack Lawrence M. Wein* , David L. Craft , and Edward H. Kaplan of an airborne anthrax attack. The system consists of an atmospheric dispersion model, an age- dependent dose­response several response strategies to a mass-casualty airborne anthrax attack in a large city. The model (Fig. 1

Li, Fei-Fei

174

Anthrax eTool: Protecting the Worksite against Terrorism  

MedlinePLUS

... OSHA requirements. What is Anthrax? | Who is at risk? | How do I prepare? | What if I have an anthrax threat? | How do I clean up my worksite? eTools Home : Anthrax Credits Freedom of Information Act | Privacy & Security Statement | Disclaimers | ...

175

Mass spectrometric detection of protein-based toxins.  

PubMed

This review focuses on mass spectrometric detection of protein-based toxins, which are among the most toxic substances known. Special emphasis is given to the bacterial toxins botulinum neurotoxin from Clostridium botulinum and anthrax toxins from Bacillus anthracis as well as the plant toxin ricin produced by Ricinus communis. A common feature, apart from their extreme toxicity, is that they are composed of 2 polypeptide chains, one of which is responsible for cell uptake and another that has enzymatic function with the ability to destroy basic cellular functions. These toxins pose a threat, both regarding natural spread and from a terrorism perspective. In order for public health and emergency response officials to take appropriate action in case of an outbreak, whether natural or intentional, there is a need for fast and reliable detection methods. Traditionally, large molecules like proteins have been detected using immunological techniques. Although sensitive, these methods suffer from some drawbacks, such as the risk of false-positives due to cross-reactions and detection of inactive toxin. This article describes recently developed instrumental methods based on mass spectrometry for the reliable detection of botulinum neurotoxins, anthrax toxins, and ricin. Unequivocal identification of a protein toxin can be carried out by mass spectrometry-based amino acid sequencing. Furthermore, in combination with antibody affinity preconcentration and biochemical tests with mass spectrometric detection demonstrating the toxin's enzymatic activity, very powerful analytical methods have been described. In conclusion, the advent of sensitive, easily operated mass spectrometers provides new possibilities for the detection of protein-based toxins. PMID:23971809

Tevell Åberg, Annica; Björnstad, Kristian; Hedeland, Mikael

2013-09-01

176

The structure of a cytolytic ?-helical toxin pore reveals its assembly mechanism  

Microsoft Academic Search

Pore-forming toxins (PFTs) are a class of potent virulence factors that convert from a soluble form to a membrane-integrated pore1. They exhibit their toxic effect either by destruction of the membrane permeability barrier or by delivery of toxic components through the pores. Among the group of bacterial PFTs are some of the most dangerous toxins, such as diphtheria and anthrax

Marcus Mueller; Ulla Grauschopf; Timm Maier; Rudi Glockshuber; Nenad Ban

2009-01-01

177

[Recombinant antibodies for medical protection against bioterrorism agents: the example of anthrax].  

PubMed

Recombinant antibodies are a highly successful class of therapeutic molecules, they are well adapted for use against bio-weapons (BW) as they act immediately, are often synergistic with other therapeutic molecules, have a long half-life and are well tolerated. Anthrax is regarded at high risk of being used as BW, and its pathogenic properties depend on toxins, which might be neutralized by antibodies. These toxins are made of three different types of sub-units (PA, LF, EF). Several anti-PA have been developed, including an original approach by our team. We have developed an anti-LF, as recommended by experts. Our anti-PA antibody, and to a lesser extend our anti-LF antibody, will be presented here. PMID:20950579

Thullier, Philippe; Pelat, Thibault; Paucod, Jean-Charles; Vidal, Dominique

2010-01-01

178

Generation of protective immune response against anthrax by oral immunization with protective antigen plant-based vaccine.  

PubMed

In concern with frequent recurrence of anthrax in endemic areas and inadvertent use of its spores as biological weapon, the development of an effective anthrax vaccine suitable for both human and veterinary needs is highly desirable. A simple oral delivery through expression in plant system could offer promising alternative to the current methods that rely on injectable vaccines extracted from bacterial sources. In the present study, we have expressed protective antigen (PA) gene in Indian mustard by Agrobacterium-mediated transformation and in tobacco by plastid transformation. Putative transgenic lines were verified for the presence of transgene and its expression by molecular analysis. PA expressed in transgenic lines was biologically active as evidenced by macrophage lysis assay. Intraperitoneal (i.p.) and oral immunization with plant PA in murine model indicated high serum PA specific IgG and IgA antibody titers. PA specific mucosal immune response was noted in orally immunized groups. Further, antibodies indicated lethal toxin neutralizing potential in-vitro and conferred protection against in-vivo toxin challenge. Oral immunization experiments demonstrated generation of immunoprotective response in mice. Thus, our study examines the feasibility of oral PA vaccine expressed in an edible plant system against anthrax. PMID:24548460

Gorantala, Jyotsna; Grover, Sonam; Rahi, Amit; Chaudhary, Prerna; Rajwanshi, Ravi; Sarin, Neera Bhalla; Bhatnagar, Rakesh

2014-04-20

179

Pertussis toxin  

SciTech Connect

This book contains 13 selections. Some of the titles are: Genetic and Functional Studies of Pertussis Toxin Substrates; Effect of Pertussis Toxin on the Hormonal Responsiveness of Different Tissues; Extracellular Adenylate Cyclase of Bordetella pertussis; and GTP-Regulatory Proteins are Introcellular Messagers: A Model for Hormone Action.

Sekura, R.D.; Moss, J.; Vaughan, M.

1985-01-01

180

Improving the anti-toxin abilities of the CMG2-Fc fusion protein with the aid of computational design.  

PubMed

CMG2-Fc is a fusion protein composed of the extracellular domain of capillary morphogenesis protein 2 (CMG2) and the Fc region of human immunoglobulin G; CMG2-Fc neutralizes anthrax toxin and offers protection against Bacillus anthracis challenge. To enhance the efficacy of CMG2-Fc against anthrax toxin, we attempted to engineer a CMG2-Fc with an improved affinity for PA. Using the automatic design algorithm FoldX and visual inspection, we devised two CMG2-Fc variants that introduce mutations in the CMG2 binding interface and improve the computationally assessed binding affinity for PA. An experimental affinity assay revealed that the two variants showed increased binding affinity, and in vitro and in vivo toxin neutralization testing indicated that one of these mutants (CMG2-Fc(E117Q)) has superior activity against anthrax toxin and was suitable for further development as a therapeutic agent for anthrax infections. This study shows that the computational design of the PA binding interface of CMG2 to obtain CMG2-Fc variants with improving anti-toxin abilities is viable. Our results demonstrate that computational design can be further applied to generate other CMG2-Fc mutants with greatly improved therapeutic efficacy. PMID:25101992

Xi, Yongyi; Wu, Xiaojie; Gao, Lihua; Shao, Yong; Peng, Hui; Chen, Hongxing; Chen, Huipeng; Hu, Xianwen; Yue, Junjie

2014-01-01

181

Increased long-term immunity to Bacillus anthracis protective antigen in mice immunized with a CIA06B-adjuvanted anthrax vaccine.  

PubMed

Anthrax is an acute infectious disease caused by Bacillus anthracis. We previously reported that the adjuvant CIA06B, which consists of TLR4 agonist CIA05 and aluminum hydroxide (alum), enhanced the immune response to anthrax protective antigen (PA) in mice. This study was carried out to determine whether CIA06B can enhance long-term immune responses to PA in mice. BALB/c mice were immunized intramuscularly three times at 2-week intervals with recombinant PA alone or PA combined with alum or CIA06B. At 8 and 24 weeks post-immunization, the immunological responses including serum anti-PA IgG antibody titer, toxin-neutralizing antibody titer, splenic cytokine secretion and the frequency of PA-specific memory B cells were assessed. Compared with mice injected with PA alone or PA plus alum, mice injected with PA plus CIA06B had higher titers of serum anti-PA IgG antibodies, and higher frequencies of PA-specific memory B cells and interferon-? secreting cells. Furthermore, anti-PA antibodies induced by CIA06B were more effective in neutralizing anthrax toxin. These results demonstrated that CIA06B is capable of providing long-term immunity when used as an adjuvant in a PA-based anthrax vaccine. PMID:23440578

Wui, Seo Ri; Han, Ji Eun; Kim, Yeon Hee; Rhie, Gi-eun; Lee, Na Gyong

2013-04-01

182

PET with radiolabeled aminoacid.  

PubMed

Since the clinical introduction of FDG, neuroimaging has been the first area of PET application in oncology. Later, while FDG-PET became progressively a key imaging modality in the management of the majority of malignancies outside the brain, its neuro-oncologic indications faced some limitations because of the unfavourable characteristics of FDG as brain tumor-seeking agent. PET applications in neuro-oncology have received new effectiveness by the advent of positron-emission labelled amino acids, so that it has been coined the term "Amino acid PET" to differentiate this imaging tool from FDG-PET. Radiolabeled amino acids are a very interesting class of PET tracers with great diagnostic potential in neuro-oncology because of their low uptake in normal brain and, conversely, high uptake in most brain tumors including low-grade gliomas. The present article surveys the results obtained using L-[methyl-11C]Methionine (MET), that has been the ancestor of PET amino acid tracers and is still the most popular amino acid imaging modality in oncology, and stresses the important role that this diagnostic modality can play in the evaluation of brain tumors. However, the use of MET is restricted to PET centers with an in-house cyclotron and radiochemistry facility, because of the short half-life (20 min) of 11C. The promising results of MET have stimulated the development of 18F-labelled aminoacid tracers, particularly O-(2-18F-fluoeoethyl1)-L-tyrosine (FET), that has the same properties of MET and, thanks to the longer half-life of 18F (about 110 min), allows a distribution strategy from a production tracer site to user satellite PET centers. Considering a more widespread use of Amino acid PET, together with the recent development of integrated PET-MRI imaging systems, and the oncoming clinical validation of other interesting PET tracers, i.e. FMISO or 18F-FAZA for hypoxia imaging and FLT for tumor proliferation imaging, it can be reasonably expected that metabolic imaging with PET is close to becoming a key diagnostic modality in the management of brain tumors, as has already been for Total Body FDG-PET/CT in extra-brain oncology. PMID:22617237

Crippa, F; Alessi, A; Serafini, G L

2012-04-01

183

Anthrax Attack! A Case on Bioterrorism  

NSDL National Science Digital Library

This case study presents a fictitious bio-terrorist plan to release anthrax in the United States. Students are assigned character roles and, through research, role-playing, and teamwork, develop a plan to minimize or avert the attack. The case is appropriate for courses designed for health professionals, general biology courses, and social science courses.

Mergenhagen, Kari A.

2003-01-01

184

76 FR 34994 - Vaccine To Protect Children From Anthrax-Public Engagement Workshop  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF HEALTH AND HUMAN SERVICES Vaccine To Protect Children From Anthrax--Public...Biodefense Science Board's (NBSB) Anthrax Vaccine (AV) Working Group (WG) will hold...workshop on July 7, 2011, to discuss vaccine to protect children from anthrax....

2011-06-15

185

Antibody response to a delayed booster dose of anthrax vaccine and botulinum toxoid.  

PubMed

We evaluated the prevalence and concentration of serum antibodies 18-24 months after primary inoculation with anthrax and botulinum vaccines, and assessed the reactogenicity and immunogenicity of a significantly delayed booster dose of these vaccines. Five hundred and eight male active-duty military personnel received one, two or three inoculations with anthrax vaccine and/or botulinum toxoid in 1990/1991 in preparation for Operations Desert Shield/Desert Storm. Subjects were vaccinated with the licensed anthrax vaccine, adsorbed (AVA) and pentavalent (ABCDE) botulinum toxoid (PBT) BB-IND 3723. Anthrax protective antigen (PA) IgG antibody was measured in serum using an immunocapture enzyme-linked immunosorbent assay (ELISA). A mouse neutralization test was used to determine the titer of Clostridium botulinum type A antitoxin in serum samples. The prevalence of anti-PA IgG was 30% in individuals 18-24 months after priming with one, two or three doses of AVA. After boosting, 99% of volunteers had detectable anti-PA IgG; only two individuals failed to respond. The prevalence of antibodies against botulinum toxin type A was 28% 18-24 months after initial priming. Following boosting, 99% of volunteers had serum titers >0.02IU/ml, and 97% responded with titers > or =0.25IU/ml. Systemic reactions to booster vaccinations could not be specifically ascribed to one or the other vaccine, but were generally mild and of brief duration. Forty-five percent of volunteers reported one or more systemic reactions over the course of 7 days. Injection site reactions of any kind occurred in 25% of AVA recipients and in 16% of PBT recipients; persistence of local reactions beyond 7 days was infrequent. While the kinetics and durability of immune responses must be studied, these findings suggest that booster doses of anthrax vaccine and botulinum toxoid sufficient to stimulate a robust anamnestic response may be given at times distant from receipt of the primary inoculations. PMID:11972980

Pittman, Phillip R; Hack, Dallas; Mangiafico, Joseph; Gibbs, Paul; McKee, Kelly T; Friedlander, Arthur M; Sjogren, Maria H

2002-05-15

186

Anthrax: a continuing concern in the era of bioterrorism  

PubMed Central

Anthrax, a potentially fatal infection, is a virulent and highly contagious disease. It is caused by a gram-positive, toxigenic, spore-forming bacillus: Bacillus anthracis. For centuries, anthrax has caused disease in animals and, although uncommonly, in humans throughout the world. Descriptions of this naturally occurring disease begin in antiquity. Anthrax is primarily a disease of herbivores, which are infected by ingestion of spores from the soil. With the advent of modern microbiology, Pasteur developed the first successful anthrax vaccine in 1881. The incidence of the disease has continually decreased since the late 19th century, and animal vaccination programs drastically reduced the animal mortality from the disease. However, anthrax spores continue to be documented in soil samples from throughout the world. Research on anthrax as a biological weapon began more than 80 years ago, and today at least 17 nations are believed to have offensive biological weapons programs that include anthrax. Recent events in the USA have shown how society is affected by both hoax and real threats of anthrax bioweapons. This fourth article in the series on weapons of biowarfare/bioterrorism summarizes the historical background of anthrax as well as clinical and laboratory information useful for bioterrorism preparedness. PMID:16200179

2005-01-01

187

Hepatic Subcellular Distribution of (3H)T-2 Toxin.  

National Technical Information Service (NTIS)

The subcellular distribution of T-2 mycotoxin and its metabolites was studied in isolated rat livers perfused with (3 tritium)T-2 toxin. After a 120-min perfusion, the distribution of radiolabel was to bile (53%), perfusate (38), and liver (7%). Livers we...

J. G. Pace, M. R. Watts

1989-01-01

188

Challenges in Disposing of Anthrax Waste  

SciTech Connect

Disasters often create large amounts of waste that must be managed as part of both immediate response and long-term recovery. While many federal, state, and local agencies have debris management plans, these plans often do not address chemical, biological, and radiological contamination. The Interagency Biological Restoration Demonstration’s (IBRD) purpose was to holistically assess all aspects of an anthrax incident and assist the development of a plan for long-term recovery. In the case of wide-area anthrax contamination and the follow-on response and recovery activities, a significant amount of material will require decontamination and disposal. Accordingly, IBRD facilitated the development of debris management plans to address contaminated waste through a series of interviews and workshops with local, state, and federal representatives. The outcome of these discussion was the identification of three primary topical areas that must be addressed: 1) Planning; 2) Unresolved research questions, and resolving regulatory issues.

Lesperance, Ann M.; Stein, Steven L.; Upton, Jaki F.; Toomey, Christopher

2011-09-01

189

Clinical microbiologists facing an anthrax alert.  

PubMed

Microbiological war and terrorist attacks are made to weaken populations by transmitting pathogenic and epidemic microorganisms. These bacteria or viruses are often difficult to diagnose. Anthrax alerts following September 2001 showed that most clinical microbiology laboratories were not adequately prepared, using obsolete diagnostic methods or being too slow to use accurate tools when facing a major threat. Following this period, most microbiology laboratories were prepared for bioterrorism alerts, in order to provide accurate and rapid results, although such events are rare and unexpected. In this review, we describe the organization and preparedness of our clinical microbiology laboratory regarding bioterrorism risk, although its main task is to perform routine diagnostic microbiology tests. To illustrate the difficulties, we briefly describe an anthrax alert. PMID:24845109

Jaton, K; Greub, G

2014-06-01

190

Emergency response to an anthrax attack  

Microsoft Academic Search

We developed a mathematical model to compare various emergency responses in the event of an airborne anthrax attack. The system consists of an atmospheric dispersion model, an age-dependent dose-response model, a disease progression model, and a set of spatially distributed two-stage queueing systems consisting of antibiotic distribution and hospital care. Our results underscore the need for the extremely aggressive and

Lawrence M. Wein; David L. Craft; Edward H. Kaplan

2003-01-01

191

Bacillus anthracis and the Pathogenesis of Anthrax  

Microsoft Academic Search

\\u000a Bacillus anthracis is the causative agent of anthrax, a disease of animals that is transmissible to humans. Because B. anthracis forms spores that can be aerosolized and sprayed with the intent to kill, this pathogen can also be viewed as an agent of\\u000a biological warfare and bioterrorism (1). The accidental release of spores into the air in Sverdlosk, Russia, and

Dominique M. Missiakas; Olaf Schneewind

192

ECONOMIC IMPACTS OF A WIDE AREA RELEASE OF ANTHRAX  

E-print Network

ECONOMIC IMPACTS OF A WIDE AREA RELEASE OF ANTHRAX May 2009 Prepared Regional Technology Center for Homeland Security Economic Impacts of a Wide Area Release of Anthrax KS, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness

193

Coordinated Response to Reports of Possible Anthrax Contamination, Idaho, 2001  

Microsoft Academic Search

In 2001, the intentional release of anthrax spores in the eastern United States increased concern about exposure to anthrax nationwide, and residents of Idaho sought assistance. Response from state and local agencies was required, increasing the strain on epidemiologists, laboratorians, and communications per- sonnel. In late 2001, Idaho's public health communications system handled 133 calls about suspicious powders. For each

Leslie Tengelsen; Richard Hudson; Shana Barnes; Christine Hahn

194

Epidemiologic Investigations of Bioterrorism-Related Anthrax, New Jersey, 2001  

Microsoft Academic Search

At least four Bacillus anthracis-containing envelopes destined for New York City and Washington, D.C. were processed at the Trenton Processing and Distribution Center (PDC) on September 18 and October 9, 2001. When cutaneous anthrax was confirmed in a Trenton postal worker, the PDC was closed. Four cutaneous and two inhalational anthrax cases were identified. Five patients were hospitalized; none died.

Carolyn M. Greene; Jennita Reefhuis; Christina Tan; Anthony E. Fiore; Susan Goldstein; Michael J. Beach; Stephen C. Redd; David Valiante; Gregory Burr; James Buehler; Robert W. Pinner; Eddy Bresnitz; Beth P. Bell

2002-01-01

195

SUSPICIOUS MAIL OR PARCELS: ANTHRAX, RICIN, CHEMICAL, BIOLOGICAL INFORMATION  

E-print Network

Bureau of Investigation (F.B.I.), U.S. Postal Service, U.S. Centers for Disease Control (CDC) and the U.S for such a response. These professionals are bound by law to respond following set protocols and procedures to threaten persons with harm. ANTHRAX Effective dispersal of anthrax is difficult due to the processes

196

Anthrax Vaccine Antigen-Adjuvant Formulations Completely Protect New Zealand White Rabbits against Challenge with Bacillus anthracis Ames Strain Spores  

PubMed Central

In an effort to develop an improved anthrax vaccine that shows high potency, five different anthrax protective antigen (PA)-adjuvant vaccine formulations that were previously found to be efficacious in a nonhuman primate model were evaluated for their efficacy in a rabbit pulmonary challenge model using Bacillus anthracis Ames strain spores. The vaccine formulations include PA adsorbed to Alhydrogel, PA encapsulated in liposomes containing monophosphoryl lipid A, stable liposomal PA oil-in-water emulsion, PA displayed on bacteriophage T4 by the intramuscular route, and PA mixed with Escherichia coli heat-labile enterotoxin administered by the needle-free transcutaneous route. Three of the vaccine formulations administered by the intramuscular or the transcutaneous route as a three-dose regimen induced 100% protection in the rabbit model. One of the formulations, liposomal PA, also induced significantly higher lethal toxin neutralizing antibodies than PA-Alhydrogel. Even 5 months after the second immunization of a two-dose regimen, rabbits vaccinated with liposomal PA were 100% protected from lethal challenge with Ames strain spores. In summary, the needle-free skin delivery and liposomal formulation that were found to be effective in two different animal model systems appear to be promising candidates for next-generation anthrax vaccine development. PMID:22089245

Peachman, Kristina K.; Li, Qin; Matyas, Gary R.; Shivachandra, Sathish B.; Lovchik, Julie; Lyons, Rick C.; Alving, Carl R.; Rao, Venigalla B.

2012-01-01

197

Identification of small molecules that inhibit the interaction of TEM8 with anthrax protective antigen using a FRET assay  

PubMed Central

Tumor marker endothelial 8 (TEM8) is a receptor for the Protective Antigen (PA) component of anthrax toxin. TEM8 is upregulated on endothelial cells lining the blood vessels within tumors, compared to normal blood vessels. A number of studies have demonstrated a pivotal role for TEM8 in developmental and tumor angiogenesis. We have also shown that targeting the anthrax receptors with a mutated form of PA inhibits angiogenesis and tumor formation in vivo. Here we describe the development and testing of a high-throughput fluorescence resonance energy transfer assay to identify molecules that strongly inhibit the interaction of PA and TEM8. The assay we describe is sensitive and robust, with a Z-prime value of 0.8. A preliminary screen of 2310 known bioactive library compounds identified ebselen and thimerosal as inhibitors of the TEM8-PA interaction. These molecules each contain a cysteine-reactive transition metal, and complimentary studies indicate that their inhibition of interaction is due to modification of a cysteine residue in the TEM8 extracellular domain. This is the first demonstration of a high-throughput screening assay that identifies inhibitors of TEM8, with potential application for anti-anthrax and anti-angiogenic diseases. PMID:23479355

Cryan, Lorna M.; Habeshian, Kaiane A.; Caldwell, Thomas P.; Morris, Meredith T.; Ackroyd, P. Christine; Christensen, Kenneth A.; Rogers, Michael S.

2013-01-01

198

Botulinum Toxin.  

National Technical Information Service (NTIS)

Botulism is a disease caused by anaerobic, spore-forming bacteria found in soil. Disease results from the actions of chemical toxins produced by these bacteria. The most common forms of human botulism include foodborne, infant, and wound. The main etiolog...

A. M. Katos, J. Anderson, M. Krasna, P. T. Williams, W. Burrows

2009-01-01

199

Intramuscular delivery of adenovirus serotype 5 vector expressing humanized protective antigen induces rapid protection against anthrax that may bypass intranasally originated preexisting adenovirus immunity.  

PubMed

Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 10? infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD??) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax. PMID:24307239

Wu, Shipo; Zhang, Zhe; Yu, Rui; Zhang, Jun; Liu, Ying; Song, Xiaohong; Yi, Shaoqiong; Liu, Ju; Chen, Jianqin; Yin, Ying; Xu, Junjie; Hou, Lihua; Chen, Wei

2014-02-01

200

Intramuscular Delivery of Adenovirus Serotype 5 Vector Expressing Humanized Protective Antigen Induces Rapid Protection against Anthrax That May Bypass Intranasally Originated Preexisting Adenovirus Immunity  

PubMed Central

Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 108 infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD50) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax. PMID:24307239

Wu, Shipo; Zhang, Zhe; Yu, Rui; Zhang, Jun; Liu, Ying; Song, Xiaohong; Yi, Shaoqiong; Liu, Ju; Chen, Jianqin; Yin, Ying; Xu, Junjie

2014-01-01

201

An anthrax lethal factor mutant that is defective at causing pyroptosis retains pro-apoptotic activity  

PubMed Central

Summary Anthrax lethal toxin triggers death in some cell types, such as macrophages, and causes a variety of cellular dysfunctions in others. Collectively, these effects dampen the innate and adaptive immune systems to allow Bacillus anthracis to survive and proliferate in the mammalian host. The diverse effects caused by the toxin have in part been attributed to its interference with signaling pathways in target cells. Lethal factor (LF) is the proteolytic component of the toxin, which cleaves six members of the mitogen activated protein kinase kinase (MAPKK) family after being delivered to the cytosol by the cell-binding component of the toxin, protective antigen. The effect of cleaving these MAPKKs is to interfere with ERK, p38 and JNK signaling. Here we characterize an LF mutant, LF-K518E/E682G, that is defective at causing pyroptosis in RAW 264.7 cells and at activating the Nlrp1b inflammasome in a heterologous expression system. LF-K518E/E682G does not exhibit an overall impairment of function, however, because it is able to downregulate the ERK pathway, but not the p38 or JNK pathways. Furthermore, LF-K518E/E682G efficiently killed melanoma cells, which were shown previously to undergo apoptosis in response to lethal toxin or to pharmacological inhibition of the ERK pathway. Our results suggest that LF-K518E/E682G is defective at cleaving a substrate involved in the activation of the Nlrp1b inflammasome. PMID:19922472

Ngai, Stephanie; Batty, Sarah; Liao, Kuo-Chieh; Mogridge, Jeremy

2009-01-01

202

[The ABCs on anthrax for health personnel].  

PubMed

The purpose of this series of articles is to present to health personnel an updated summary on bioterrorism associated agents. In this first article an updated summary on anthrax is presented. Emphasis has been placed on the characteristics of cases which occurred during October in the United States of America and on the experience of governmental agencies of that country to face the emergency. Measures implemented in Mexico are described as well. The authors are convinced that the best arm against terror is timely and updated information. PMID:11816237

Valdespino-Gómez, J L; García-García, M L

2001-01-01

203

Injectional anthrax - new presentation of an old disease.  

PubMed

Bacillus anthracis infection (anthrax) has three distinct clinical presentations depending on the route of exposure: cutaneous, gastrointestinal and inhalational anthrax. Each of these can lead to secondary bacteraemia and anthrax meningitis. Since 2009,anthrax has emerged among heroin users in Europe,presenting a novel clinical manifestation, 'injectional anthrax', which has been attributed to contaminated heroin distributed throughout Europe; before 2009 only one case was reported. During 2012 and 2013,new cases of injectional anthrax were diagnosed in Denmark, France, Germany, and the United Kingdom.Here we present a comprehensive review of the literature and information derived from different reporting systems until 31 December 2013. Overall 70 confirmed cases were reported, with 26 fatalities (37% case fatality rate).The latest two confirmed cases occurred in March 2013. Thirteen case reports have been published,describing 18 confirmed cases. Sixteen of these presented as a severe soft tissue infection that differed clinically from cutaneous anthrax, lacked the characteristic epidemiological history of animal contact and ten cases required complimentary surgical debridement. These unfamiliar characteristics have led to delays of three to 12 days in diagnosis, inadequate treatment and a high fatality rate. Clinicians' awareness of this recently described clinical entity is key for early 'and successful management of patients. PMID:25139073

Berger, T; Kassirer, M; Aran, A A

2014-01-01

204

Vaccination of Rhesus Macaques with the Anthrax Vaccine Adsorbed Vaccine Produces a Serum Antibody Response That Effectively Neutralizes Receptor-Bound Protective Antigen In Vitro ?  

PubMed Central

Anthrax toxin (ATx) is composed of the binary exotoxins lethal toxin (LTx) and edema toxin (ETx). They have separate effector proteins (edema factor and lethal factor) but have the same binding protein, protective antigen (PA). PA is the primary immunogen in the current licensed vaccine anthrax vaccine adsorbed (AVA [BioThrax]). AVA confers protective immunity by stimulating production of ATx-neutralizing antibodies, which could block the intoxication process at several steps (binding of PA to the target cell surface, furin cleavage, toxin complex formation, and binding/translocation of ATx into the cell). To evaluate ATx neutralization by anti-AVA antibodies, we developed two low-temperature LTx neutralization activity (TNA) assays that distinguish antibody blocking before and after binding of PA to target cells (noncomplexed [NC] and receptor-bound [RB] TNA assays). These assays were used to investigate anti-PA antibody responses in AVA-vaccinated rhesus macaques (Macaca mulatta) that survived an aerosol challenge with Bacillus anthracis Ames spores. Results showed that macaque anti-AVA sera neutralized LTx in vitro, even when PA was prebound to cells. Neutralization titers in surviving versus nonsurviving animals and between prechallenge and postchallenge activities were highly correlated. These data demonstrate that AVA stimulates a myriad of antibodies that recognize multiple neutralizing epitopes and confirm that change, loss, or occlusion of epitopes after PA is processed from PA83 to PA63 at the cell surface does not significantly affect in vitro neutralizing efficacy. Furthermore, these data support the idea that the full-length PA83 monomer is an appropriate immunogen for inclusion in next-generation anthrax vaccines. PMID:20739500

Clement, Kristin H.; Rudge, Thomas L.; Mayfield, Heather J.; Carlton, Lena A.; Hester, Arelis; Niemuth, Nancy A.; Sabourin, Carol L.; Brys, April M.; Quinn, Conrad P.

2010-01-01

205

[Preliminary trials of oral immunization of wild animals against anthrax].  

PubMed

As a pilot trial for the vaccination of game in African game parks against anthrax, trials with guinea-pigs were undertaken to vaccinate the animals orally against anthrax. The vaccine has been prepared with the Göettingen Bioreactor Technology obtaining sporulation in suspension. Guinea-pigs vaccinated orally and subcutaneously with the vaccine resisted a challenge of 1000 spores with a pathogen field strain isolated from elephants in Zambia. With a challenge dosis of 2500 spores orally and subcutaneously immunized animals died. A technique has been developed to identify anthrax organisms excreted with the faeces by means of gas chromatography. PMID:8067984

Rengel, J; Böhnel, H

1994-05-01

206

Further Insights into Brevetoxin Metabolism by de Novo Radiolabeling  

PubMed Central

The toxic dinoflagellate Karenia brevis, responsible for early harmful algal blooms in the Gulf of Mexico, produces many secondary metabolites, including potent neurotoxins called brevetoxins (PbTx). These compounds have been identified as toxic agents for humans, and they are also responsible for the deaths of several marine organisms. The overall biosynthesis of these highly complex metabolites has not been fully ascertained, even if there is little doubt on a polyketide origin. In addition to gaining some insights into the metabolic events involved in the biosynthesis of these compounds, feeding studies with labeled precursors helps to discriminate between the de novo biosynthesis of toxins and conversion of stored intermediates into final toxic products in the response to environmental stresses. In this context, the use of radiolabeled precursors is well suited as it allows working with the highest sensitive techniques and consequently with a minor amount of cultured dinoflagellates. We were then able to incorporate [U-14C]-acetate, the renowned precursor of the polyketide pathway, in several PbTx produced by K. brevis. The specific activities of PbTx-1, -2, -3, and -7, identified by High-Resolution Electrospray Ionization Mass Spectrometer (HRESIMS), were assessed by HPLC-UV and highly sensitive Radio-TLC counting. We demonstrated that working at close to natural concentrations of acetate is a requirement for biosynthetic studies, highlighting the importance of highly sensitive radiolabeling feeding experiments. Quantification of the specific activity of the four, targeted toxins led us to propose that PbTx-1 and PbTx-2 aldehydes originate from oxidation of the primary alcohols of PbTx-7 and PbTx-3, respectively. This approach will open the way for a better comprehension of the metabolic pathways leading to PbTx but also to a better understanding of their regulation by environmental factors. PMID:24918358

Calabro, Kevin; Guigonis, Jean-Marie; Teyssie, Jean-Louis; Oberhansli, Francois; Goudour, Jean-Pierre; Warnau, Michel; Dechraoui Bottein, Marie-Yasmine; Thomas, Olivier P.

2014-01-01

207

Intrinsically radiolabeled nanoparticles: an emerging paradigm.  

PubMed

Although chelator-based radiolabeling techniques have been used for decades, concerns about the complexity of coordination chemistry, possible altering of pharmacokinetics of carriers, and potential detachment of radioisotopes during imaging have driven the need for developing a simple yet better technique for future radiolabeling. Here, the emerging concept of intrinsically radiolabeled nanoparticles, which could be synthesized using methods such as hot-plus-cold precursors, specific trapping, cation exchange, and proton beam activation, is introduced. Representative examples of using these multifunctional nanoparticles for multimodality molecular imaging are highlighted together with current challenges and future research directions. Although still in the early stages, design and synthesis of intrinsically radiolabeled nanoparticles has shown attractive potential to offer easier, faster, and more specific radiolabeling possibilities for the next generation of molecular imaging. PMID:24978934

Goel, Shreya; Chen, Feng; Ehlerding, Emily B; Cai, Weibo

2014-10-01

208

Identification of anthrax-specific signature sequence from Bacillus anthracis  

NASA Astrophysics Data System (ADS)

The primary objective was to identify and clone novel chromosomal DNA fragments for use as B. anthracis-specific markers. Towards this goal, 300 random primers (RAPD technology, randomly amplified polymorphic DNA) were screened to identify polymorphic loci on the anthrax chromosome. Five such DNA fragments uniquely amplifying from anthrax chromosome were identified and isolated. These fragments were cloned in pCR vector and sequenced. Database (genebank) analysis of one of the cloned probe, VRTC899, revealed the presence of specific chromosomal DNA probe, Ba813 from anthrax. This prove also contains flanking DNA with no homology to known sequences. Availability of signature DNA probes for detection of antrax-causing agent in environmental samples is critical for field application of DNA-based sensor technologies. In conclusion, we have demonstrated application of RAPD technology for identification of anthrax-specific signature sequences. This strategy can be extended to identify signature sequences from other BW agents.

Rastogi, Vipin K.; Cheng, Tu-chen

2001-08-01

209

[Anthrax--continuous threat to humans and animals].  

PubMed

Gram-positive, spore-forming, aerobic bacterium Bacillus anthracis is an etiological agent of anthrax a disease very dangerous to humans and all warm-blooded animals. The spore forms are markedly resistant to unfavourable environmental extremes of heat, cold, desiccation, chemicals, irradiation etc. The vegetative forms characterised virulence factors: the antiphagocytic poly-gamma-D-polipeptide capsule and three proteins, edema factor (EF), lethal factor (LF) and protective antigen (PA). Anthrax is mainly transmitted from animals to man through food of animal origin, animal products and contamination of the environment with B. anthracis and its spores. There are three types of this disease: cutaneous, intestinal and inhalation anthrax. Research on anthrax as a biological weapon began more then 80 years ago. Depending on the target chosen and the scale of the attack the anthrax spores may by used to contaminate of foodstuffs or liquids and water. The aerosolised release of anthrax spore can cause illness with a high fatality rate. PMID:15517814

Mizak, Lidia

2004-01-01

210

Emergency response to an anthrax attack  

PubMed Central

We developed a mathematical model to compare various emergency responses in the event of an airborne anthrax attack. The system consists of an atmospheric dispersion model, an age-dependent dose–response model, a disease progression model, and a set of spatially distributed two-stage queueing systems consisting of antibiotic distribution and hospital care. Our results underscore the need for the extremely aggressive and timely use of oral antibiotics by all asymptomatics in the exposure region, distributed either preattack or by nonprofessionals postattack, and the creation of surge capacity for supportive hospital care via expanded training of nonemergency care workers at the local level and the use of federal and military resources and nationwide medical volunteers. The use of prioritization (based on disease stage and/or age) at both queues, and the development and deployment of modestly rapid and sensitive biosensors, while helpful, produce only second-order improvements. PMID:12651951

Wein, Lawrence M.; Craft, David L.; Kaplan, Edward H.

2003-01-01

211

Vibrio cholerae: Cholera toxin  

Microsoft Academic Search

The bacterial protein toxin of Vibrio cholerae, cholera toxin, is a major agent involved in severe diarrhoeal disease. Cholera toxin is a member of the AB toxin family and is composed of a catalytically active heterodimeric A-subunit linked with a homopentameric B-subunit. Upon binding to its receptor, GM01, cholera toxin is internalized and transported in a retrograde manner through the

Davy Vanden Broeck; Caroline Horvath; Marc J. S. De Wolf

2007-01-01

212

Screen-printed fluorescent sensors for rapid and sensitive anthrax biomarker detection.  

PubMed

Since the 2001 anthrax attacks, efforts have focused on the development of an anthrax detector with rapid response and high selectivity and sensitivity. Here, we demonstrate a fluorescence sensor for detecting anthrax biomarker with high sensitivity and selectivity using a screen-printing method. A lanthanide-ethylenediamine tetraacetic acid complex was printed on a flexible polyethersulfone film. Screen-printing deposition of fluorescent detecting moieties produced fluorescent patterns that acted as a visual alarm against anthrax. PMID:23518174

Lee, Inkyu; Oh, Wan-Kyu; Jang, Jyongsik

2013-05-15

213

Localization of tumors by radiolabelled antibodies  

Microsoft Academic Search

A method of utilizing radiolabelled antibodies to carcinoembryonic antigens for determining the site of tumors which produce or are associated with carcinoembryonic antigen is disclosed. 3 claims, no drawings.

H. J. Hansen; F. J. Primus

1975-01-01

214

Predictability of anthrax infection in the Serengeti, Tanzania  

PubMed Central

Summary Anthrax is endemic throughout Africa, causing considerable livestock and wildlife losses and severe, sometimes fatal, infection in humans. Predicting the risk of infection is therefore important for public health, wildlife conservation and livestock economies. However, because of the intermittent and variable nature of anthrax outbreaks, associated environmental and climatic conditions, and diversity of species affected, the ecology of this multihost pathogen is poorly understood. We explored records of anthrax from the Serengeti ecosystem in north-west Tanzania where the disease has been documented in humans, domestic animals and a range of wildlife. Using spatial and temporal case-detection and seroprevalence data from wild and domestic animals, we investigated spatial, environmental, climatic and species-specific associations in exposure and disease. Anthrax was detected annually in numerous species, but large outbreaks were spatially localized, mostly affecting a few focal herbivores. Soil alkalinity and cumulative weather extremes were identified as useful spatial and temporal predictors of exposure and infection risk, and for triggering the onset of large outbreaks. Interacting ecological and behavioural factors, specifically functional groups and spatiotemporal overlap, helped to explain the variable patterns of infection and exposure among species. Synthesis and applications. Our results shed light on ecological drivers of anthrax infection and suggest that soil alkalinity and prolonged droughts or rains are useful predictors of disease occurrence that could guide risk-based surveillance. These insights should inform strategies for managing anthrax including prophylactic livestock vaccination, timing of public health warnings and antibiotic provision in high-risk areas. However, this research highlights the need for greater surveillance (environmental, serological and case-detection-orientated) to determine the mechanisms underlying anthrax dynamics. PMID:22318563

Hampson, Katie; Lembo, Tiziana; Bessell, Paul; Auty, Harriet; Packer, Craig; Halliday, Jo; Beesley, Cari A.; Fyumagwa, Robert; Hoare, Richard; Ernest, Eblate; Mentzel, Christine; Metzger, Kristine L.; Mlengeya, Titus; Stamey, Karen; Roberts, Keith; Wilkins, Patricia P.; Cleaveland, Sarah

2012-01-01

215

Predictability of anthrax infection in the Serengeti, Tanzania.  

PubMed

Anthrax is endemic throughout Africa, causing considerable livestock and wildlife losses and severe, sometimes fatal, infection in humans. Predicting the risk of infection is therefore important for public health, wildlife conservation and livestock economies. However, because of the intermittent and variable nature of anthrax outbreaks, associated environmental and climatic conditions, and diversity of species affected, the ecology of this multihost pathogen is poorly understood.We explored records of anthrax from the Serengeti ecosystem in north-west Tanzania where the disease has been documented in humans, domestic animals and a range of wildlife. Using spatial and temporal case-detection and seroprevalence data from wild and domestic animals, we investigated spatial, environmental, climatic and species-specific associations in exposure and disease.Anthrax was detected annually in numerous species, but large outbreaks were spatially localized, mostly affecting a few focal herbivores.Soil alkalinity and cumulative weather extremes were identified as useful spatial and temporal predictors of exposure and infection risk, and for triggering the onset of large outbreaks.Interacting ecological and behavioural factors, specifically functional groups and spatiotemporal overlap, helped to explain the variable patterns of infection and exposure among species.Synthesis and applications. Our results shed light on ecological drivers of anthrax infection and suggest that soil alkalinity and prolonged droughts or rains are useful predictors of disease occurrence that could guide risk-based surveillance. These insights should inform strategies for managing anthrax including prophylactic livestock vaccination, timing of public health warnings and antibiotic provision in high-risk areas. However, this research highlights the need for greater surveillance (environmental, serological and case-detection-orientated) to determine the mechanisms underlying anthrax dynamics. PMID:22318563

Hampson, Katie; Lembo, Tiziana; Bessell, Paul; Auty, Harriet; Packer, Craig; Halliday, Jo; Beesley, Cari A; Fyumagwa, Robert; Hoare, Richard; Ernest, Eblate; Mentzel, Christine; Metzger, Kristine L; Mlengeya, Titus; Stamey, Karen; Roberts, Keith; Wilkins, Patricia P; Cleaveland, Sarah

2011-06-10

216

A fragment of anthrax lethal factor delivers proteins to the cytosol without requiring protective antigen  

E-print Network

A fragment of anthrax lethal factor delivers proteins to the cytosol without requiring protective) Anthrax protective antigen (PA) is a 735-aa polypeptide that facili- tates the exit of anthrax lethal as a carrier to deliver antigens into the cytosol for efficient induction of T lymphocyte responses

Lieberman, Judy

217

TNF-? detection using a flow cytometric assay to determine cellular responses to anthrax vaccine  

Microsoft Academic Search

This study describes a four-color flow cytometric assay that detects CD4+ T cell responses to the anthrax vaccine. Whole blood from seven volunteers who previously obtained the anthrax vaccine was inoculated in vitro with varying concentrations of the anthrax antigen. TNF-? and IFN-? production from memory CD4+ T cells were measured and compared to a control group who never received

Annie H. Shinn; Normita C. Bravo; Holden T. Maecker; James W. Smith

2003-01-01

218

Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event Symposium  

E-print Network

Anthrax Symposium Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event in the response communities. Pacific Northwest National Laboratory serves as the Onsite Integrator for the IBRD. The Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event Symposium was held on March 19, 2008

219

Quantitative Models of the Dose-Response and Time Course of Inhalational Anthrax in Humans  

E-print Network

Quantitative Models of the Dose-Response and Time Course of Inhalational Anthrax in Humans Damon J and non-human primates are often contradictory. We review existing quantitative inhalational anthrax dose-response of Utah, Salt Lake City, Utah, United States of America Abstract Anthrax poses a community health risk due

Adler, Fred

220

Multi-Reward Policies for Medical Applications: Anthrax Attacks and Smart Wheelchairs  

E-print Network

first study the multi-criteria anthrax response problem; after a qualitative discussion of the bestMulti-Reward Policies for Medical Applications: Anthrax Attacks and Smart Wheelchairs Harold Soh in the medical domain: anthrax re- sponse and smart-wheelchair control. For the first problem, we use a discrete

Demiris, Yiannis

221

Clinical Presentation of Inhalational Anthrax Following Bioterrorism Exposure Report of 2 Surviving Patients  

Microsoft Academic Search

The use of anthrax as a weapon of biological terrorism has moved from theory to reality in recent weeks. Following processing of a letter containing anthrax spores that had been mailed to a US senator, 5 cases of inhalational anthrax have occurred among postal workers employed at a major postal facility in Wash- ington, DC. This report details the clinical

Thom A. Mayer; Susan Bersoff-Matcha; Cecele Murphy; James Earls; Scott Harper; Denis Pauze; Michael Nguyen; Jonathan Rosenthal; Donald Cerva; Glenn Druckenbrod; Dan Hanfling; Naaz Fatteh; Anthony Napoli; Ashna Nayyar; Elise L. Berman

222

Investigation and control of anthrax outbreak at the human-animal interface, Bhutan, 2010.  

PubMed

In 2010, we investigated anthrax outbreak in Bhutan. A total of 43 domestic animals died, and cutaneous anthrax developed in 9 persons, and 1 died. All affected persons had contact with the carcasses of infected animals. Comprehensive preparedness and response guidelines are needed to increase public awareness of anthrax in Bhutan. PMID:25147965

Thapa, Nirmal K; Tenzin; Wangdi, Karma; Dorji, Tshering; Migma; Dorjee, Jambay; Marston, Chung K; Hoffmaster, Alex R

2014-09-01

223

Investigation and Control of Anthrax Outbreak at the Human-Animal Interface, Bhutan, 2010  

PubMed Central

In 2010, we investigated anthrax outbreak in Bhutan. A total of 43 domestic animals died, and cutaneous anthrax developed in 9 persons, and 1 died. All affected persons had contact with the carcasses of infected animals. Comprehensive preparedness and response guidelines are needed to increase public awareness of anthrax in Bhutan. PMID:25147965

Thapa, Nirmal K.; Wangdi, Karma; Dorji, Tshering; Dorjee, Jambay; Marston, Chung K.; Hoffmaster, Alex R.

2014-01-01

224

Public response to an anthrax attack: reactions to mass prophylaxis in a scenario involving inhalation anthrax from an unidentified source.  

PubMed

An attack with Bacillus anthracis ("anthrax") is a known threat to the United States. When weaponized, it can cause inhalation anthrax, the deadliest form of the disease. Due to the rapid course of inhalation anthrax, delays in initiation of antibiotics may decrease survival chances. Because a rapid response would require cooperation from the public, there is a need to understand the public's response to possible mass dispensing programs. To examine the public's response to a mass prophylaxis program, this study used a nationally representative poll of 1,092 adults, supplemented by a targeted focus on 3 metropolitan areas where anthrax attacks occurred in 2001: New York City (n=517), Washington, DC (n=509), and Trenton/Mercer County, NJ (n=507). The poll was built around a "worst-case scenario" in which cases of inhalation anthrax are discovered without an identified source and the entire population of a city or town is asked to receive antibiotic prophylaxis within a 48-hour period. Findings from this poll provide important signs of public willingness to comply with public health recommendations for obtaining antibiotics from a dispensing site, although they also indicate that public health officials may face several challenges to compliance, including misinformation about the contagiousness of inhalation anthrax; fears about personal safety in crowds; distrust of government agencies to provide sufficient, safe, and effective medicine; and hesitation about ingesting antibiotic pills after receiving them. In general, people living in areas where anthrax attacks occurred in 2001 had responses similar to those of the nation as a whole. PMID:21819225

SteelFisher, Gillian; Blendon, Robert; Ross, Laura J; Collins, Blanche C; Ben-Porath, Eran N; Bekheit, Mark M; Mailhot, Johanna R

2011-09-01

225

A MATHEMATICAL SIMULATION OF THE INFLAMMATORY RESPONSE TO ANTHRAX INFECTION  

PubMed Central

Bacillus anthracis (anthrax) can trigger an acute inflammatory response that results in multisystem organ failure and death. Previously, we developed a mathematical model of acute inflammation after gram-negative infection that had been matched qualitatively to literature data. We modified the properties of the invading bacteria in that model to those specific to B. anthracis and simulated the host response to anthrax infection. We simulated treatment strategies against anthrax in a genetically diverse population including the following: (1) antibiotic treatment initiated at various time points, (2) antiprotective antigen vaccine, and (3) a combination of antibiotics and vaccine. In agreement with studies in mice, our simulations showed that antibiotics only improve survival if administered early in the course of anthrax infection. Vaccination that leads to the formation of antibodies to protective antigen is anti-inflammatory and beneficial in averting shock and improving survival. However, antibodies to protective antigen alone are predicted not to be universally protective against anthrax infection. Rather, our simulations suggest that an optimal strategy would require both vaccination and antibiotic administration. PMID:18157069

Kumar, Rukmini; Chow, Carson C.; Bartels, John D.; Clermont, Gilles; Vodovotz, Yoram

2013-01-01

226

Identification of small molecules that inhibit the interaction of TEM8 with anthrax protective antigen using a FRET assay.  

PubMed

Tumor marker endothelial 8 (TEM8) is a receptor for the protective antigen (PA) component of anthrax toxin. TEM8 is upregulated on endothelial cells lining the blood vessels within tumors, compared with normal blood vessels. A number of studies have demonstrated a pivotal role for TEM8 in developmental and tumor angiogenesis. We have also shown that targeting the anthrax receptors with a mutated form of PA inhibits angiogenesis and tumor formation in vivo. Here we describe the development and testing of a high-throughput fluorescence resonance energy transfer assay to identify molecules that strongly inhibit the interaction of PA and TEM8. The assay we describe is sensitive and robust, with a Z' value of 0.8. A preliminary screen of 2310 known bioactive library compounds identified ebselen and thimerosal as inhibitors of the TEM8-PA interaction. These molecules each contain a cysteine-reactive transition metal, and complementary studies indicate that their inhibition of interaction is due to modification of a cysteine residue in the TEM8 extracellular domain. This is the first demonstration of a high-throughput screening assay that identifies inhibitors of TEM8, with potential application for antianthrax and antiangiogenic diseases. PMID:23479355

Cryan, Lorna M; Habeshian, Kaiane A; Caldwell, Thomas P; Morris, Meredith T; Ackroyd, P Christine; Christensen, Kenneth A; Rogers, Michael S

2013-07-01

227

Sverdlovsk Anthrax Outbreak: An Educational Case Study  

NASA Astrophysics Data System (ADS)

In April and May of 1979 an Anthrax epidemic broke out in the city of Sverdlovsk (now Ekaterinburg) in the former Soviet Union. Sixty-four people were reported to have died from the outbreak, although there is still debate concerning the actual number of victims. While Soviet officials initially attributed this outbreak to contaminated meat, the US Government maintained that the outbreak was due to a leakage from a biological weapons facility. We have created and implemented an undergraduate educational exercise based on the forensic analysis of this event. Students were provided case data of the victims, area satellite images and meteorological data. One goal of the exercise was for students to reconstruct the most probable scenario of events through valid inference based on the limited information and uncertainties associated with the data set. Another goal was to make students sensitive to issues of biological weapons and bioterrorism. The exercise was highly rated by students even before the events of September 11. There is a clear need to educate students, particularly in the sciences, to be aware of the signatures of terrorist activities. Evidence of terrorist activities is more likely to appear from unintended discoveries than from active intelligence gathering. We believe our national security can be enhanced by sensitizing those that monitor the natural environment to the signatures of terrorist activities through the types of educational exercises that we have developed.

Steele, S. J.; van der Vink, G.

2002-05-01

228

Wanted, an Anthrax vaccine: Dead or Alive?  

PubMed Central

It has been more than 100 years since the realization that microbes are capable of causing disease. In that time, we have learned a great deal as to how each organism has adapted to the immune system so as to avoid elimination. As well, we have also learned an immense amount since Louis Pasteur first proposed that the solution to infectious diseases was to culture the microbes and attenuate their virulence, so as to use them as vaccines. From the optimism and promise of the 19th century and immunization as the ultimate answer to the invasion by the microbial world, to the scientific realities of the 21st century, it is of interest to retrace the steps of the earliest microbiologists cum immunologists, to realize how far we've come, as well as how far we yet have to go. This editorial focuses on the history of anthrax as a microbial disease, and the earliest efforts at producing a vaccine for its prevention. PMID:15836780

Smith, Kendall A

2005-01-01

229

Radiolabeled Nanoparticles for Multimodality Tumor Imaging  

PubMed Central

Each imaging modality has its own unique strengths. Multimodality imaging, taking advantages of strengths from two or more imaging modalities, can provide overall structural, functional, and molecular information, offering the prospect of improved diagnostic and therapeutic monitoring abilities. The devices of molecular imaging with multimodality and multifunction are of great value for cancer diagnosis and treatment, and greatly accelerate the development of radionuclide-based multimodal molecular imaging. Radiolabeled nanoparticles bearing intrinsic properties have gained great interest in multimodality tumor imaging over the past decade. Significant breakthrough has been made toward the development of various radiolabeled nanoparticles, which can be used as novel cancer diagnostic tools in multimodality imaging systems. It is expected that quantitative multimodality imaging with multifunctional radiolabeled nanoparticles will afford accurate and precise assessment of biological signatures in cancer in a real-time manner and thus, pave the path towards personalized cancer medicine. This review addresses advantages and challenges in developing multimodality imaging probes by using different types of nanoparticles, and summarizes the recent advances in the applications of radiolabeled nanoparticles for multimodal imaging of tumor. The key issues involved in the translation of radiolabeled nanoparticles to the clinic are also discussed. PMID:24505237

Xing, Yan; Zhao, Jinhua; Conti, Peter S.; Chen, Kai

2014-01-01

230

Structure-based redesign of an edema toxin inhibitor  

PubMed Central

Edema Factor toxin (EF) of Bacillus anthracis (NIAID category A), and several other toxins from NIAID category B Biodefense target bacteria are adenylyl cyclases or adenylyl cyclase agonists that catalyze the conversion of ATP to 3?,5?-cyclic adenosine monophosphate (cAMP). We previously identified compound 1 (3-[(9-Oxo-9H-fluorene-1-carbonyl)-amino]-benzoic acid), that inhibits EF activity in cultured mammalian cells, and reduces diarrhea caused by enterotoxigenic Escherichia coli (ETEC) at an oral dosage of 15 ?g/mouse. Here, molecular docking was used to predict improvements in potency and solubility of new derivatives of compound 1 in inhibiting edema toxin-(ET) catalyzed stimulation of cyclic AMP production in murine monocyte-macrophage cells (RAW 264.7). Structure-activity relationship (SAR) analysis of the bioassay results for 22 compounds indicated positions important for activity. Several derivatives demonstrated superior pharmacological properties compared to our initial lead compound, and are promising candidates to treat anthrax infections and diarrheal diseases induced by toxin-producing bacteria. PMID:22154558

Chen, Deliang; Ma, Lili; Kanalas, John J.; Gao, Jian; Pawlik, Jennifer; Jimenez, Maria Estrella; Walter, Mary A.; Peterson, Johnny W.; Gilbertson, Scott R.; Schein, Catherine H.

2011-01-01

231

Analysis of anti-protective antigen IgG subclass distribution in recipients of anthrax vaccine adsorbed (AVA) and patients with cutaneous and inhalation anthrax  

Microsoft Academic Search

The anti-PA IgG1, IgG2, IgG3, and IgG4 subclass responses to clinical anthrax and to different numbers of anthrax vaccine adsorbed (AVA, BioThrax®) injections were determined in a cross-sectional study of sera from 63 vaccinees and 13 clinical anthrax patients. The data show that both vaccination with three AVA injections and clinical anthrax elicit anti-PA IgG1, IgG2, and IgG3 subclass responses.

V. A. Semenova; D. S. Schmidt; T. H. Taylor Jr.; H. Li; E. Steward-Clark; S. D. Soroka; M. M. Ballard; C. P. Quinn

2007-01-01

232

Toxines botuliques : utilisation pratique  

Microsoft Academic Search

Botulinum toxins (A and B) are neurotoxins derived from Clostridium botulinum. Clostridium are anaerobic bacteria. C. botulinum produces exotoxins (A to G) with distinct antigenicities. The neurotoxins inhibit the release of the neurotransmitter acetylcholine from the axon terminals of motor neurons. Botulinum toxin is officially used in clinic for the treatment of muscular hyperactivity (strabismus, blepharospam, cervical dystonia). Botulinum toxins

A Durand; G Serment

2003-01-01

233

Toxins of Amanita phalloides  

Microsoft Academic Search

The most poisonous mushroom toxins are produced by Amanita phalloides (death cap). The occurrence and chemistry of three groups of toxins (amatoxins, phallotoxins and virotoxins) are summarized. The concentration and distribution of toxins in certain species are variable, with the young fruit body containing lower, and the well-developed fungus higher concentrations, but there is a high variability among specimens collected

János Vetter

1998-01-01

234

Recombinant Protective Antigen Anthrax Vaccine Improves Survival when Administered as a Postexposure Prophylaxis Countermeasure with Antibiotic in the New Zealand White Rabbit Model of Inhalation Anthrax  

PubMed Central

Inhalation anthrax is a potentially lethal form of disease resulting from exposure to aerosolized Bacillus anthracis spores. Over the last decade, incidents spanning from the deliberate mailing of B. anthracis spores to incidental exposures in users of illegal drugs have highlighted the importance of developing new medical countermeasures to protect people who have been exposed to “anthrax spores” and are at risk of developing disease. The New Zealand White rabbit (NZWR) is a well-characterized model that has a pathogenesis and clinical presentation similar to those seen in humans. This article reports how the NZWR model was adapted to evaluate postexposure prophylaxis using a recombinant protective antigen (rPA) vaccine in combination with an oral antibiotic, levofloxacin. NZWRs were exposed to multiples of the 50% lethal dose (LD50) of B. anthracis spores and then vaccinated immediately (day 0) and again on day 7 postexposure. Levofloxacin was administered daily beginning at 6 to 12 h postexposure for 7 treatments. Rabbits were evaluated for clinical signs of disease, fever, bacteremia, immune response, and survival. A robust immune response (IgG anti-rPA and toxin-neutralizing antibodies) was observed in all vaccinated groups on days 10 to 12. Levofloxacin plus either 30 or 100 ?g rPA vaccine resulted in a 100% survival rate (18 of 18 per group), and a vaccine dose as low as 10 ?g rPA resulted in an 89% survival rate (16 of 18) when used in combination with levofloxacin. In NZWRs that received antibiotic alone, the survival rate was 56% (10 of 18). There was no adverse effect on the development of a specific IgG response to rPA in unchallenged NZWRs that received the combination treatment of vaccine plus antibiotic. This study demonstrated that an accelerated two-dose regimen of rPA vaccine coadministered on days 0 and 7 with 7 days of levofloxacin therapy results in a significantly greater survival rate than with antibiotic treatment alone. Combination of vaccine administration and antibiotic treatment may be an effective strategy for treating a population exposed to aerosolized B. anthracis spores. PMID:22695155

Bourdage, James S.; Williamson, E. Diane; Duchars, Matthew; Fuerst, Thomas R.; Fusco, Peter C.

2012-01-01

235

Multifunctional radiolabeled nanoparticles for targeted therapy.  

PubMed

Nanoparticles can be near infrared (NIR)-fluorescent (e.g., gold nanoparticles, quantum dots or carbon nanotubes) or can have magnetic properties (e.g., iron oxide nanoparticles). These optical or magnetic properties can be exploited for use in thermal therapy and molecular imaging. Radiolabeled nanoparticles have proven to be promising tools in the diagnosis and therapy of malignant processes due to their multivalency and as multi-modal imaging agents. Furthermore, these radiopharmaceuticals may function simultaneously as both radiotherapy systems and thermal-ablation systems. This review examines the application of radiolabeled nanoparticles in the development of multifunctional nanosystems for targeted therapy. PMID:23992338

Ferro-Flores, G; Ocampo-García, B E; Santos-Cuevas, C L; Morales-Avila, E; Azorín-Vega, E

2014-01-01

236

Immunologic Response of Unvaccinated Workers Exposed to Anthrax, Belgium  

Microsoft Academic Search

ndustrial anthrax, also known as woolsorter's disease, was a serious threat in the 19th and early 20th centuries when the wool industry was flourishing. The causal agent, Bacillus anthracis, was brought into factories in sporulated form with the organic matter that was contaminating the animal fibers. The pathogen provoked the characteristic necrotic lesions on the skin of the wool workers

Pierre Wattiau; Marc Govaerts; Dimitrios Frangoulidis; David Fretin; Esther Kissling; Mieke Van Hessche; Bernard China; Martine Poncin; Yvo Pirenne; Germaine Hanquet

237

Anthrax 2001: Observations on the Medical and Public Health Response  

Microsoft Academic Search

HIS ARTICLE DESCRIBES ASPECTS of the medical and public health response to the 2001 anthrax attacks based on interviews with individuals who were directly involved in the response. It has been more than 18 months since B. anthracis spores were discovered in let- ters sent through the U.S. postal system. The specific purpose and perpetrator(s) of these attacks remain un-

Elin Gursky; Thomas V. Inglesby; Tara O'Toole

2003-01-01

238

Analyzing Bioterror Response Logistics: The Case of Anthrax  

Microsoft Academic Search

To aid in understanding how best to respond to a bioterror anthrax attack, we analyze a system of differential equations that includes an atmospheric release model, a spatial array of biosensors, a dose-response model, a disease progression model, and a set of spatially distributed tandem queues for distributing antibiotics and providing hospital care. We derive approximate closed-form expressions for the

David L. Craft; Lawrence M. Wein; Alexander H. Wilkins

2005-01-01

239

Cutaneous Anthrax—the Non-industrial Hazard  

PubMed Central

Two patients contracted cutaneous anthrax after contact with infected bone meal. Awareness of the risk of infection from this source may help in achieving early clinical diagnosis and a low fatality rate following effective antibiotic therapy. ImagesFig. 1Fig. 2Fig. 3Fig. 4 PMID:4974297

Knight, A. H.; Wynne-Williams, C. J. E.; Willis, A. T.

1969-01-01

240

Cutaneous anthrax in Turkey: a review of 32 cases.  

PubMed

Anthrax, caused by the Gram-positive, rod-shaped, spore-forming bacterium Bacillus anthracis, is rarely seen in industrialized nations but is common in developing countries. Cutaneous anthrax accounts for 95% of cases and usually develops on exposed sites. This study reviews the clinical and laboratory findings of 32 patients diagnosed with cutaneous anthrax over a 4-y period in the eastern part of Turkey. All patients had a history of direct contact with infected animals. The patients, aged 6-72 y, comprised 17 (53%) males and 15 (47%) females. The most frequent localization site of skin lesions was the hands and fingers (31 patients), whereas the suborbital part of the face was invaded in 1 patient. The diagnosis was made as a result of typical clinical lesions, direct microscopy or bacterial isolation. All but 2 patients were successfully treated with penicillin; these other 2 patients were treated initially with sulbactam-ampicillin. All patients, including the patient with suborbital anthrax, were cured. PMID:12160166

Oncül, O; Ozsoy, M F; Gul, H C; Koçak, N; Cavuslu, S; Pahsa, A

2002-01-01

241

Detection and Sterilization of Anthrax Spores by Microwave Radiation.  

National Technical Information Service (NTIS)

The goal of this program is to investigate the ability of microwave and millimeter-wave radiation to detect and destroy biological agents, with a particular focus on anthrax spores. Dry constituents, such as dipicolinic acid (DPA), can be placed within si...

N. C. Luhmann, C. W. Domier, A. Wan, M. Johnson

2005-01-01

242

Microfluidic radiolabeling of biomolecules with PET radiometals  

PubMed Central

Introduction A robust, versatile and compact microreactor has been designed, fabricated and tested for the labeling of bifunctional chelate conjugated biomolecules (BFC-BM) with PET radiometals. Methods The developed microreactor was used to radiolabel a chelate, either 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) that had been conjugated to cyclo(Arg-Gly-Asp-DPhe-Lys) peptide, with both 64Cu and 68Ga respectively. The microreactor radiolabeling conditions were optimized by varying temperature, concentration and residence time. Results Direct comparisons between the microreactor approach and conventional methods showed improved labeling yields and increased reproducibility with the microreactor under identical labeling conditions, due to enhanced mass and heat transfer at the microscale. More importantly, over 90% radiolabeling yields (incorporation of radiometal) were achieved with a 1:1 stoichiometry of bifunctional chelate biomolecule conjugate (BFC-BM) to radiometal in the microreactor, which potentially obviates extensive chromatographic purification that is typically required to remove the large excess of unlabeled biomolecule in radioligands prepared using conventional methods. Moreover, higher yields for radiolabeling of DOTA-functionalized BSA protein (Bovine Serum Albumin) were observed with 64Cu/68Ga using the microreactor, which demonstrates the ability to label both small and large molecules. Conclusions A robust, reliable, compact microreactor capable of chelating radiometals with common chelates has been developed and validated. Based on our radiolabeling results, the reported microfluidic approach overall outperforms conventional radiosynthetic methods, and is a promising technology for the radiometal labeling of commonly utilized BFC-BM in aqueous solutions. PMID:23078875

Zeng, Dexing; Desai, Amit V.; Ranganathan, David; Wheeler, Tobias D.; Kenis, Paul J. A.; Reichert, David E.

2012-01-01

243

Single-step purification of recombinant anthrax lethal factor from periplasm of Escherichia coli.  

PubMed

Lethal toxin (LT) that composed by protective antigen and lethal factor (LF) is the major virulence factor of Bacillus anthracis. The treatments of LT in animals could reproduce most manifestations of B. anthracis infections that greatly improves our knowledge in LT-mediated pathogenesis and facilitates anthrax-related researches without having to directly contact the hazardous bacterium B. anthracis. The recombinant protein of LF (rLF), however, still lacks a simple purification method. Herein, we developed single-step nickel affinity purification of rLF with yield up to 3mg/l. By fusion to the leader sequence of outer membrane protein OmpA, rLF could easily be purified from the periplasm of Escherichia coli. To investigate whether the rLT is functional in our system, both wild type rLF and the catalytic mutant rLF that contains a single amino acid substitution at zinc-binding site (LF(E687A)), were subjected to macrophage cytotoxicity analysis. Our data showed that the rLT is fully functional, while the LF(E687A) fail to induce cell death of tested macrophage cells. These findings suggested that the purification protocol herein is a user-friendly method that allows researchers to obtain the functional rLF by single-step purification. PMID:16797097

Chang, Hsin-Hou; Tsai, Mei-Fang; Chung, Chia-Pei; Chen, Po-Kong; Hu, Hsin-I; Kau, Jyh-Hwa; Huang, Hsin-Hsien; Lin, Hung-Chi; Sun, Der-Shan

2006-11-10

244

Toxin inhibition of antimicrobial factors induced by Bacillus anthracis peptidoglycan in human blood.  

PubMed

Here, we describe the capacity of Bacillus anthracis peptidoglycan (BaPGN) to trigger an antimicrobial response in human white blood cells (WBCs). Analysis of freshly isolated human blood cells found that monocytes and neutrophils, but not B and T cells, were highly responsive to BaPGN and produced a variety of cytokines and chemokines. This BaPGN-induced response was suppressed by anthrax lethal toxin (LT) and edema toxin (ET), with the most pronounced effect on human monocytes, and this corresponded with the higher levels of anthrax toxin receptor 1 (ANTXR1) in these cells than in neutrophils. The supernatant from BaPGN-treated cells altered the growth of B. anthracis Sterne, and this effect was blocked by LT, but not by ET. An FtsX mutant of B. anthracis known to be resistant to the antimicrobial effects of interferon-inducible Glu-Leu-Arg (ELR)-negative CXC chemokines was not affected by the BaPGN-induced antimicrobial effects. Collectively, these findings describe a system in which BaPGN triggers expression of antimicrobial factors in human WBCs and reveal a distinctive role, not shared with ET, in LT's capacity to suppress this response. PMID:23876807

Barua, Soumitra; Iyer, Janaki K; Larabee, Jason L; Raisley, Brent; Hughes, Molly A; Coggeshall, K Mark; Ballard, Jimmy D

2013-10-01

245

Receptor-directed chimeric toxins created by sortase-mediated protein fusion  

PubMed Central

Chimeric protein toxins that act selectively on cells expressing a designated receptor may serve as investigational probes and/or antitumor agents. Here we report use of the enzyme sortase A (SrtA) to create 4 chimeric toxins designed to selectively kill cells bearing the tumor marker, HER2. We first expressed and purified: (i) a receptor recognition-deficient form of diphtheria toxin (DT) that lacks its receptor binding domain and (ii) a mutated, receptor-binding-deficient form of anthrax protective antigen (PA). Both proteins carried at the C terminus the sortase recognition sequence LPETGG and a H6 affinity tag. Each toxin protein was mixed with SrtA plus either of two HER2-recognition proteins—a single-chain antibody fragment or an Affibody—both carrying an N terminal G5 tag. With wild-type SrtA the fusion reaction between the toxin and receptor-recognition proteins approached completion only after several hours, whereas with an evolved form of the enzyme, SrtA*, the reaction was virtually complete within 5 minutes. The four fusion toxins were purified and shown to kill HER2-positive cells in culture with high specificity. Sortase-mediated ligation of binary combinations of diverse natively folded proteins offers a facile way to produce large sets of chimeric proteins for research and medicine. PMID:23945077

McCluskey, Andrew J.; Collier, R. John

2013-01-01

246

[Hemolysis of Scolopendra toxins].  

PubMed

The hemolysis of toxins from alive Scolopendra subspinipes mutilans, medicinal material of Scolopendra subspimipes mutilans and S. multidens have been compared. The result shows that all the toxins have hemolytic activity. The hemolytic activity of the toxin from the medicinal materials of S. subspinipes mutilans is obviously lower than that from alive ones, and that from fresh medicinal materials are twice as high that from old ones, and that from S. multidens is higher than that from S. subspinipes multilans. PMID:12572496

Deng, F; Fang, H; Wang, K

1997-01-01

247

Ankylosing spondylitis is associated with the anthrax toxin receptor 2 gene (ANTXR2)  

PubMed Central

Objectives ANTXR2 variants have been associated with ankylosing spondylitis (AS) in two previous genome-wide association studies (GWAS) (p?9×10?8). However, a genome-wide significant association (p<5×10?8) was not observed. We conducted a more comprehensive analysis of ANTXR2 in an independent UK sample to confirm and refine this association. Methods A replication study was carried out with 2978 cases and 8365 controls. Then, these were combined with non-overlapping samples from the two previous GWAS in a meta-analysis. Human leukocyte antigen (HLA)-B27 stratification was also performed to test for ANTXR2-HLA-B27 interaction. Results Out of nine single nucleotide polymorphisms (SNP) in the study, five SNPs were nominally associated (p<0.05) with AS in the replication dataset. In the meta-analysis, eight SNPs showed evidence of association, the strongest being with rs12504282 (OR=0.88, p=6.7×10?9). Seven of these SNPs showed evidence for association in the HLA-B27-positive subgroup, but none was associated with HLA-B27-negative AS. However, no statistically significant interaction was detected between HLA-B27 and ANTXR2 variants. Conclusions ANTXR2 variants are clearly associated with AS. The top SNPs from two previous GWAS (rs4333130 and rs4389526) and this study (rs12504282) are in strong linkage disequilibrium (r2?0.76). All are located near a putative regulatory region. Further studies are required to clarify the role played by these ANTXR2 variants in AS. PMID:25169729

Karaderi, T; Keidel, S M; Pointon, J J; Appleton, L H; Brown, M A; Evans, D M; Wordsworth, B P

2014-01-01

248

Toxin-antitoxin systems  

PubMed Central

Toxin–antitoxin (TA) systems are small genetic elements composed of a toxin gene and its cognate antitoxin. The toxins of all known TA systems are proteins while the antitoxins are either proteins or non-coding RNAs. Based on the molecular nature of the antitoxin and its mode of interaction with the toxin the TA modules are currently grouped into five classes. In general, the toxin is more stable than the antitoxin but the latter is expressed to a higher level. If supply of the antitoxin stops, for instance under special growth conditions or by plasmid loss in case of plasmid encoded TA systems, the antitoxin is rapidly degraded and can no longer counteract the toxin. Consequently, the toxin becomes activated and can act on its cellular targets. Typically, TA toxins act on crucial cellular processes including translation, replication, cytoskeleton formation, membrane integrity, and cell wall biosynthesis. TA systems and their components are also versatile tools for a multitude of purposes in basic research and biotechnology. Currently, TA systems are frequently used for selection in cloning and for single protein expression in living bacterial cells. Since several TA toxins exhibit activity in yeast and mammalian cells they may be useful for applications in eukaryotic systems. TA modules are also considered as promising targets for the development of antibacterial drugs and their potential to combat viral infection may aid in controlling infectious diseases. PMID:24251069

Unterholzner, Simon J; Poppenberger, Brigitte; Rozhon, Wilfried

2013-01-01

249

Impedance spectroscopy for the detection and identification of unknown toxins  

NASA Astrophysics Data System (ADS)

Advancements in biological and chemical warfare has allowed for the creation of novel toxins necessitating a universal, real-time sensor. We have used a function-based biosensor employing impedance spectroscopy using a low current density AC signal over a range of frequencies (62.5 Hz-64 kHz) to measure the electrical impedance of a confluent epithelial cell monolayer at 120 sec intervals. Madin Darby canine kidney (MDCK) epithelial cells were grown to confluence on thin film interdigitated gold electrodes. A stable impedance measurement of 2200 ? was found after 24 hrs of growth. After exposure to cytotoxins anthrax lethal toxin and etoposide, the impedance decreased in a linear fashion resulting in a 50% drop in impedance over 50hrs showing significant difference from the control sample (~20% decrease). Immunofluorescent imaging showed that apoptosis was induced through the addition of toxins. Similarities of the impedance signal shows that the mechanism of cellular death was the same between ALT and etoposide. A revised equivalent circuit model was employed in order to quantify morphological changes in the cell monolayer such as tight junction integrity and cell surface area coverage. This model showed a faster response to cytotoxin (2 hrs) compared to raw measurements (20 hrs). We demonstrate that herein that impedance spectroscopy of epithelial monolayers serves as a real-time non-destructive sensor for unknown pathogens.

Riggs, B. C.; Plopper, G. E.; Paluh, J. L.; Phamduy, T. B.; Corr, D. T.; Chrisey, D. B.

2012-06-01

250

Integrated MOSFET-Embedded-Cantilever-Based Biosensor Characteristic for Detection of Anthrax Simulant  

SciTech Connect

In this work, MOSFET-embedded cantilevers are configured as microbial sensors for detection of anthrax simulants, Bacillus thuringiensis. Anthrax simulants attached to the chemically treated gold-coated cantilever cause changes in the MOSFET drain current due to the bending of the cantilever which indicates the detection of anthrax simulant. Electrical properties of the anthrax simulant are also responsible for the change in the drain current. The test results suggest a detection range of 10 L of stimulant test solution (a suspension population of 1.3 107 colony-forming units/mL diluted in 40% ethanol and 60% deionized water) with a linear response of 31 A/ L.

Mostafa, Salwa [University of Tennessee, Knoxville (UTK); Lee, Ida [ORNL; Islam, Syed K [University of Tennessee, Knoxville (UTK); Eliza, Sazia A. [University of Tennessee, Knoxville (UTK); Shekhawat, Gajendra [Northwestern University, Evanston; Dravid, Vinayak [Northwestern University, Evanston; Tulip, Fahmida S [ORNL

2011-01-01

251

(CDC) giving 10 000 postal workers suspected confirmed exposed anthrax two-month dose antibiotics. CDC recommended people failed complete regimen high risk exposure take antibiotics additional 40 days supplemental anthrax vaccine.  

EPA Pesticide Factsheets

Search instead for (CDC) giving 10 000 postal workers suspected confirmed exposed anthrax two-month dose antibiotics. CDC recommended people failed complete regimen high risk exposure take antibiotics additional 40 days supplemental anthrax vaccine. ?

252

Evaluation of mucoadhesive carrier adjuvant: toward an oral anthrax vaccine.  

PubMed

The aim of present study was to evaluate the potential of mucoadhesive alginate-coated chitosan microparticles (A-CHMp) for oral vaccine against anthrax. The zeta potential of A-CHMp was -29.7 mV, and alginate coating could prevent the burst release of antigen in simulated gastric fluid. The results indicated that A-CHMp was mucoadhesive in nature and transported it to the peyer's patch upon oral delivery. The immunization studies indicated that A-CHMp resulted in the induction of potent systemic and mucosal immune responses, whereas alum-adjuvanted rPA could induce only systemic immune response. Thus, A-CHMp represents a promising acid carrier adjuvant for oral immunization against anthrax. PMID:23452384

Mangal, Sharad; Pawar, Dilip; Agrawal, Udita; Jain, Arvind K; Vyas, Suresh P

2014-02-01

253

Risk factors associated with anthrax in cattle on smallholdings.  

PubMed

SUMMARY Unprecedented high rates of anthrax outbreaks have been observed recently in cattle and humans in Bangladesh, with 607 human cases in 2010. By enrolling 15 case and 15 control cattle smallholdings in the spatial zone in July-September 2010, we conducted a case-control study, data of which were analysed by matched-pair analysis and multivariable conditional logistic regression. Feeding animals with uprooted and unwashed grass [odds ratio (OR) 41·2, 95% confidence interval (CI) 3·7-458·8, P=0·003], and feeding water hyacinth (Eichhornia crassipes) (OR 22·2, 95% CI 1·2-418·7, P=0·039) were independent risk factors for anthrax in cattle. PMID:22123521

Biswas, P K; Islam, M Z; Shil, S K; Chakraborty, R K; Ahmed, S S U; Christensen, J P

2012-10-01

254

Adverse medical events in British service personnel following anthrax vaccination  

Microsoft Academic Search

The safety of the UK anthrax vaccine in British service personnel was evaluated by a retrospective cohort study of randomly selected personnel from five Royal Air Force bases by investigating adverse medical events and consultation rates for a period before and after vaccination. Vaccination acceptance rate varied from 27 to 89% (P=0.0001). In the vaccinated cohort 11.1% (n=368) reported side-effects.

Joanne E Enstone; Martin C. J Wale; Jonathan S Nguyen-Van-Tam; James C. G Pearson

2003-01-01

255

Public response to an anthrax attack: a multiethnic perspective.  

PubMed

The 2001 anthrax attacks emphasized the need to develop outreach that would more effectively support racial/ethnic minority populations during a bioterrorism incident. Given the importance of antibiotic prophylaxis in a future anthrax attack, it should be a priority to better support racial/ethnic minorities in mass dispensing programs. To examine the needs and perspectives of racial/ethnic minorities, this study used a nationally representative poll of 1,852 adults, including 1,240 whites, 261 African Americans, and 282 Hispanics. The poll examined public reactions to a ''worst-case scenario'' in which cases of inhalation anthrax are discovered without an identified source and the entire population of a city or town is asked to receive antibiotic prophylaxis within 48 hours. Findings suggest willingness across all racial/ethnic groups to comply with recommendations to seek prophylaxis at dispensing sites. However, findings also indicate possible barriers for racial/ethnic minorities, including greater concern about pill safety and multiple attacks as well as lesser knowledge about inhalation anthrax. Across all racial/ethnic groups, roughly half would prefer to receive antibiotics at mass dispensing sites rather than through the US Postal Service. People in racial/ethnic minority groups were more likely to say this preference stems from a desire to speak with staff or to exchange medication formulation or type. Findings suggest the need for tailored outreach to racial/ethnic minorities through, for example, emphasis on key messages and enhanced understandability in communications, increased staff for answering questions in relevant dispensing sites, and long-term trust building with racial/ethnic minority communities. PMID:23244501

Steelfisher, Gillian K; Blendon, Robert J; Brulé, Amanda S; Ben-Porath, Eran N; Ross, Laura J; Atkins, Bret M

2012-12-01

256

Immunological dynamics in response to two anthrax vaccines in mice  

Microsoft Academic Search

In order to understand the variation of humoral and cellular immune responses to A16R live spore and AVA vaccine and to identify\\u000a efficient immunological parameters for the early evaluation of post immunization in mice, we dynamically monitored the antibody\\u000a production and cellular responses after the vaccination of Balb\\/C mice with the anthrax vaccines. The results show that both\\u000a anti-AVA and

Jin Lü; Rui He; Mei Dong; LiangYan Zhang; XiLiang Wang

2008-01-01

257

What I need to know about anthrax today.  

PubMed

The US Department of Defense has been concerned about the use of anthrax as a biological weapon by an enemy on US troops for a number of years. This is the reason why the military has embarked on a vaccination program for its forces deployed to regions of the world, which are considered high-risk areas. These areas have been in the Southwest Asia-Persian Gulf region as well as the Korean Peninsula. Many intelligence personnel have also been concerned about the possibility of biological agents being used by terrorists in the Continental United States. The recent anthrax incidents in Florida and elsewhere in the United States have significantly heightened concerns along these lines, especially following the terrorist attacks on the World Trade Center and the Pentagon on September 11th. The death of a Florida businessman, identification of infection in one of his co-workers, evidence of exposure and in some instances, cutaneous infection in some others, as well as evidence of contamination in their buildings, raised further concerns of the possibility of terrorist activity using biological warfare in this country. It is somewhat ironic that a disease that you probably haven't heard about since medical school has become the focus of national attention. Our goal in this communication is to refresh your understanding of what anthrax is and what you need to know about it today since anthrax is counted among the weapons of mass destruction. As a member of the medical profession, you will need to know what to look for in patients and how to treat them if they are contaminated with this biological agent. You will also have to serve as the "front line" of the public health system and alert the police and public health agencies. PMID:11787310

Harris, R D; Grabenstein, J D

2001-12-01

258

Improvement of a Potential Anthrax Therapeutic by Computational Protein Design*  

PubMed Central

Past anthrax attacks in the United States have highlighted the need for improved measures against bioweapons. The virulence of anthrax stems from the shielding properties of the Bacillus anthracis poly-?-d-glutamic acid capsule. In the presence of excess CapD, a B. anthracis ?-glutamyl transpeptidase, the protective capsule is degraded, and the immune system can successfully combat infection. Although CapD shows promise as a next generation protein therapeutic against anthrax, improvements in production, stability, and therapeutic formulation are needed. In this study, we addressed several of these problems through computational protein engineering techniques. We show that circular permutation of CapD improved production properties and dramatically increased kinetic thermostability. At 45 °C, CapD was completely inactive after 5 min, but circularly permuted CapD remained almost entirely active after 30 min. In addition, we identify an amino acid substitution that dramatically decreased transpeptidation activity but not hydrolysis. Subsequently, we show that this mutant had a diminished capsule degradation activity, suggesting that CapD catalyzes capsule degradation through a transpeptidation reaction with endogenous amino acids and peptides in serum rather than hydrolysis. PMID:21768086

Wu, Sean J.; Eiben, Christopher B.; Carra, John H.; Huang, Ivan; Zong, David; Liu, Peixian; Wu, Cindy T.; Nivala, Jeff; Dunbar, Josef; Huber, Tomas; Senft, Jeffrey; Schokman, Rowena; Smith, Matthew D.; Mills, Jeremy H.; Friedlander, Arthur M.; Baker, David; Siegel, Justin B.

2011-01-01

259

HEPA/Vaccine Plan for Indoor Anthrax Remediation  

PubMed Central

We developed a mathematical model to compare 2 indoor remediation strategies in the aftermath of an outdoor release of 1.5 kg of anthrax spores in lower Manhattan. The 2 strategies are the fumigation approach used after the 2001 postal anthrax attack and a HEPA/vaccine plan, which relies on HEPA vacuuming, HEPA air cleaners, and vaccination of reoccupants. The HEPA/vaccine approach leads to few anthrax cases among reoccupants if applied to all but the most heavily contaminated buildings, and recovery is much faster than under the decades-long fumigation plan. Only modest environmental sampling is needed. A surge capacity of 10,000 to 20,000 Hazmat workers is required to perform remediation within 6 to 12 months and to avoid permanent mass relocation. Because of the possibility of a campaign of terrorist attacks, serious consideration should be given to allowing or encouraging voluntary self-service cleaning of lightly contaminated rooms by age-appropriate, vaccinated, partially protected (through masks or hoods) reoccupants or owners. PMID:15705325

Liu, Yifan; Leighton, Terrance J.

2005-01-01

260

Pathology and Pathogenesis of Bioterrorism-Related Inhalational Anthrax  

PubMed Central

During October and November 2001, public health authorities investigated 11 patients with inhalational anthrax related to a bioterrorism attack in the United States. Formalin-fixed samples from 8 patients were available for pathological and immunohistochemical (IHC) study using monoclonal antibodies against the Bacillus anthracis cell wall and capsule. Prominent serosanguinous pleural effusions and hemorrhagic mediastinitis were found in 5 patients who died. Pulmonary infiltrates seen on chest radiographs corresponded to intraalveolar edema and hyaline membranes. IHC assays demonstrated abundant intra- and extracellular bacilli, bacillary fragments, and granular antigen-staining in mediastinal lymph nodes, surrounding soft tissues, and pleura. IHC staining in lung, liver, spleen, and intestine was present primarily inside blood vessels and sinusoids. Gram’s staining of tissues was not consistently positive. In 3 surviving patients, IHC of pleural samples demonstrated abundant granular antigen-staining and rare bacilli while transbronchial biopsies showed granular antigen-staining in interstitial cells. In surviving patients, bacilli were not observed with gram’s stains. Pathological and IHC studies of patients who died of bioterrorism-related inhalational anthrax confirmed the route of infection. IHC was indispensable for diagnosis of surviving anthrax cases. The presence of B. anthracis antigens in the pleurae could explain the prominent and persistent hemorrhagic pleural effusions. PMID:12875989

Guarner, Jeannette; Jernigan, John A.; Shieh, Wun-Ju; Tatti, Kathleen; Flannagan, Lisa M.; Stephens, David S.; Popovic, Tanja; Ashford, David A.; Perkins, Bradley A.; Zaki, Sherif R.

2003-01-01

261

Novel inhibitors of Anthrax edema factor  

PubMed Central

Several pathogenic bacteria produce adenylyl cyclase toxins, such as the edema factor (EF) of Bacillus anthracis. These disturb cellular metabolism by catalyzing production of excessive amounts of the regulatory molecule cAMP. Here, a structure-based method, where a 3D- pharmacophore that fit the active site of EF was constructed from fragments, was used to identify non-nucleotide inhibitors of EF. A library of small molecule fragments was docked to the EF- active site in existing crystal structures and those with the highest HINT scores were assembled into a 3D-pharmacophore. About 10,000 compounds, from over 2.7 million compounds in the ZINC database, had a similar molecular framework. These were ranked according to their docking scores, using methodology that was shown to achieve maximum accuracy (i.e., how well the docked position matched the experimentally determined site for ATP analogues in crystal structures of the complex). Finally, 19 diverse compounds with the best AutoDock binding/docking scores were assayed in a cell based assay for their ability to reduce cAMP secretion induced by EF. Four of the test compounds, from different structural groups, inhibited in the low micromolar range. One of these has a core structure common to phosphatase inhibitors previously identified by high-throughput assays of a diversity library. Thus, the fragment based pharmacophore identified a small number of diverse compounds for assay, and greatly enhanced the selection process of advanced lead compounds for combinatorial design. PMID:18620864

Chen, Deliang; Misra, Milind; Sower, Laurie; Peterson, Johnny W.; Kellogg, Glen E.; Schein, Catherine H.

2008-01-01

262

Two-Photon Intravital Imaging of Lungs during Anthrax Infection Reveals Long-Lasting Macrophage-Dendritic Cell Contacts  

E-print Network

to the draining lymph nodes and elicit the immune response in pulmonary anthrax. The intimate and long-last- ingTwo-Photon Intravital Imaging of Lungs during Anthrax Infection Reveals Long-Lasting Macrophage, the agent of anthrax. We show that after alveolar macrophages capture spores, CD11b-positive dendritic cells

Paris-Sud XI, Université de

263

A Three-Dose Intramuscular Injection Schedule of Anthrax Vaccine Adsorbed Generates Sustained Humoral and Cellular Immune Responses to Protective Antigen and Provides Long-Term Protection against Inhalation Anthrax in Rhesus Macaques  

PubMed Central

A 3-dose (0, 1, and 6 months) intramuscular (3-IM) priming series of a human dose (HuAVA) and dilutions of up to 1:10 of anthrax vaccine adsorbed (AVA) provided statistically significant levels of protection (60 to 100%) against inhalation anthrax for up to 4 years in rhesus macaques. Serum anti-protective antigen (anti-PA) IgG and lethal toxin neutralization activity (TNA) were detectable following a single injection of HuAVA or 1:5 AVA or following two injections of diluted vaccine (1:10, 1:20, or 1:40 AVA). Anti-PA and TNA were highly correlated (overall r2 = 0.89 for log10-transformed data). Peak responses were seen at 6.5 months. In general, with the exception of animals receiving 1:40 AVA, serum anti-PA and TNA responses remained significantly above control levels at 28.5 months (the last time point measured for 1:20 AVA), and through 50.5 months for the HuAVA and 1:5 and 1:10 AVA groups (P < 0.05). PA-specific gamma interferon (IFN-?) and interleukin-4 (IL-4) CD4+ cell frequencies and T cell stimulation indices were sustained through 50.5 months (the last time point measured). PA-specific memory B cell frequencies were highly variable but, in general, were detectable in peripheral blood mononuclear cells (PBMC) by 2 months, were significantly above control levels by 7 months, and remained detectable in the HuAVA and 1:5 and 1:20 AVA groups through 42 months (the last time point measured). HuAVA and diluted AVA elicited a combined Th1/Th2 response and robust immunological priming, with sustained production of high-avidity PA-specific functional antibody, long-term immune cell competence, and immunological memory (30 months for 1:20 AVA and 52 months for 1:10 AVA). Vaccinated animals surviving inhalation anthrax developed high-magnitude anamnestic anti-PA IgG and TNA responses. PMID:22933399

Sabourin, Carol L.; Niemuth, Nancy A.; Li, Han; Semenova, Vera A.; Rudge, Thomas L.; Mayfield, Heather J.; Schiffer, Jarad; Mittler, Robert S.; Ibegbu, Chris C.; Wrammert, Jens; Ahmed, Rafi; Brys, April M.; Hunt, Robert E.; Levesque, Denyse; Estep, James E.; Barnewall, Roy E.; Robinson, David M.; Plikaytis, Brian D.; Marano, Nina

2012-01-01

264

Identification of a Protein Subset of the Anthrax Spore Immunome in Humans Immunized with the Anthrax Vaccine Adsorbed Preparation  

PubMed Central

We identified spore targets of Anthrax Vaccine Adsorbed (AVA)-induced immunity in humans by screening recombinant clones of a previously generated, limited genomic Bacillus anthracis Sterne (pXO1+, pXO2?) expression library of putative spore surface (spore-associated [SA]) proteins with pooled sera from human adults immunized with AVA (immune sera), the anthrax vaccine currently approved for use by humans in the United States. We identified 69 clones that reacted specifically with pooled immune sera but not with pooled sera obtained from the same individuals prior to immunization. Positive clones expressed proteins previously identified as localized on the anthrax spore surface, proteins highly expressed during spore germination, orthologs of proteins of diverse pathogens under investigation as drug targets, and orthologs of proteins contributing to the virulence of both gram-positive and gram-negative pathogens. Among the reactive clones identified by this immunological screen was one expressing a 15.2-kDa hypothetical protein encoded by a gene with no significant homology to sequences contained in databases. Further studies are required to define the subset of SA proteins identified in this study that contribute to the virulence of this pathogen. We hypothesize that optimal delivery of a subset of SA proteins identified by such studies to the immune system in combination with protective antigen (PA), the principal immunogen in AVA, might facilitate the development of defined, nonreactogenic, more-efficacious PA-based anthrax vaccines. Future studies might also facilitate the identification of SA proteins with potential to serve as targets for drug design, spore inactivation, or spore detection strategies. PMID:16113286

Kudva, Indira T.; Griffin, Robert W.; Garren, Jeonifer M.; Calderwood, Stephen B.; John, Manohar

2005-01-01

265

In vivo murine and in vitro M-like cell models of gastrointestinal anthrax.  

PubMed

Bacillus anthracis is the causative agent of anthrax and is acquired by three routes of infection: inhalational, gastrointestinal and cutaneous. Gastrointestinal (GI) anthrax is rare, but can rapidly result in severe, systemic disease that is fatal in 25%-60% of cases. Disease mechanisms of GI anthrax remain unclear due to limited numbers of clinical cases and the lack of experimental animal models. Here, we developed an in vivo murine model of GI anthrax where spore survival was maximized through the neutralization of stomach acid followed by an intragastric administration of a thiabendazole paste spore formulation. Infected mice showed a dose-dependent mortality rate and pathological features closely mimicking human GI anthrax. Since Peyer's patches in the murine intestine are the primary sites of B. anthracis growth, we developed a human M (microfold)-like-cell model using a Caco-2/Raji B-cell co-culturing system to study invasive mechanisms of GI anthrax across the intestinal epithelium. Translocation of B. anthracis spores was higher in M-like cells than Caco-2 monolayers, suggesting that M-like cells may serve as an initial entry site for spores. Here, we developed an in vivo murine model of GI anthrax and an in vitro M-like cell model that could be used to further our knowledge of GI anthrax pathogenesis. PMID:23108317

Tonry, Jessica H; Popov, Serguei G; Narayanan, Aarthi; Kashanchi, Fatah; Hakami, Ramin M; Carpenter, Calvin; Bailey, Charles; Chung, Myung-Chul

2013-01-01

266

The role of HLA–DR–DQ haplotypes in variable antibody responses to Anthrax Vaccine Adsorbed  

Microsoft Academic Search

Host genetic variation, particularly within the human leukocyte antigen (HLA) loci, reportedly mediates heterogeneity in immune response to certain vaccines; however, no large study of genetic determinants of anthrax vaccine response has been described. We searched for associations between the immunoglobulin G antibody to protective antigen (AbPA) response to Anthrax Vaccine Adsorbed (AVA) in humans, and polymorphisms at HLA class

N M Pajewski; S D Parker; G A Poland; I G Ovsyannikova; W Song; K Zhang; B A McKinney; V S Pankratz; J C Edberg; R P Kimberly; R M Jacobson; J Tang; R A Kaslow

2011-01-01

267

Validation of an anti-PA-ELISA for the potency testing of anthrax vaccine in mice  

Microsoft Academic Search

The potency test for the anthrax vaccine currently licensed for human use in the United States (Anthrax Vaccine Adsorbed) involves the protection of actively immunized guinea pigs from a lethal challenge with a virulent strain of Bacillus anthracis. Lethal challenge tests entail the use of specialized containment facilities for the safe and secure handling of the challenge strain. This potential

María Pombo; Inge Berthold; Elise Gingrich; María Jaramillo; Mary Leef; Lev Sirota; Henry Hsu; Juan Arciniega

2004-01-01

268

Spokespersons and Message Control: How the CDC Lost Credibility during the Anthrax Crisis  

Microsoft Academic Search

This study evaluates the role of spokespersons and message control in complex organizations facing ambiguous crises. Specifically, the Centers for Disease Control and Prevention's (CDC) response to the anthrax crisis in 2001 is offered as a case study. A textual analysis of CDC telebriefings and corresponding print media coverage of the anthrax crisis reveals the use of multiple spokespersons and

M. Scott Barrett

2005-01-01

269

Multiple Imputation by Ordered Monotone Blocks with Application to the Anthrax Vaccine Research Program  

E-print Network

Multiple Imputation by Ordered Monotone Blocks with Application to the Anthrax Vaccine Research with missing values. The CDC Anthrax Vaccine Research Program (AVRP) dataset created new challenges for MI due's research is partially funded by NSF-SES grant 11-31897. The content is solely the responsibility

West, Mike

270

Medical counterbioterrorism: The response to provide anthrax prophylaxis to New York city US postal service employees  

Microsoft Academic Search

Study objective: We describe and analyze a recent rapid deployment of disaster medical assistance teams and other government agencies to provide medical screening and anthrax prophylaxis to New York City US Postal Service employees potentially exposed to letters contaminated with anthrax spores. Methods: A description of the response effort is presented. Data were collected on standardized forms and included the

Robert Partridge; John Alexander; Tom Lawrence; Selim Suner

2003-01-01

271

UK armed forces responses to an informed consent policy for anthrax vaccination: A paradoxical effect?  

Microsoft Academic Search

BackgroundIn recognition of concerns that anthrax vaccination might be a trigger for “Gulf war syndrome”, anthrax vaccinations were offered to UK armed forces in the 2003 Iraq conflict using explicit as opposed to implicit consent, as is the policy for all other vaccinations. This paper examines responses of personnel to this policy.

Dominic Murphy; Christopher Dandeker; Oded Horn; Matthew Hotopf; Lisa Hull; Margaret Jones; Theresa Marteau; Roberto Rona; Simon Wessely

2006-01-01

272

Animal toxins and the kidney  

Microsoft Academic Search

Envenomation or poisoning by toxins from animals poses an important health hazard in the tropics. Animal toxins are complex mixtures of proteins, peptides, enzymes and chemicals. These toxins exert their effects through modulation of ion channels and receptors, and via direct enzyme action. Depolarization or hyperpolarization of ion channels—caused by most marine toxins, and some snake and insect venoms—results in

Visith Sitprija

2008-01-01

273

Self-Assembled Peptide Monolayers as a Toxin Sensing Mechanism within Arrayed Microchannels  

PubMed Central

A sensor for the lethal bacterial enzyme, botulinum neurotoxin type A (BoNT/A), was developed using self-assembled monolayers (SAMs). SAMs consisting of an immobilized synthetic peptide that mimicked the toxin’s in vivo SNAP-25 protein substrate were formed on Au and interfaced with arrayed microfluidic channels. Efforts to optimize SAM composition and assay conditions for greatest reaction efficiency and sensitivity are described in detail. Channel design provided facile fluid manipulation, sample incubation, analyte concentration, and fluorescence detection all within a single microfluidic channel, thus avoiding sample transfer and loss. Peptide SAMs were exposed to varying concentrations of BoNT/A or its catalytic light chain (ALC), resulting in enzymatic cleavage of the peptide substrate from the surface. Fluorescence detection was achieved down to 20 pg/mL ALC and 3 pg/ mL BoNT/A in 3 h. Toxin sensing was also accomplished in vegetable soup, demonstrating practicality of the method. The modular design of this microfluidic SAM platform allows for extension to sensing other toxins that operate via enzymatic cleavage, such as the remaining BoNT serotypes B–G, anthrax, and tetanus toxin. PMID:19253949

Frisk, Megan L.; Tepp, William H.; Johnson, Eric A.; Beebe, David J.

2009-01-01

274

Bacterial toxins: friends or foes?  

PubMed Central

Many emerging and reemerging bacterial pathogens synthesize toxins that serve as primary virulence factors. We highlight seven bacterial toxins produced by well-established or newly emergent pathogenic microbes. These toxins, which affect eukaryotic cells by a variety of means, include Staphylococcus aureus alpha-toxin, Shiga toxin, cytotoxic necrotizing factor type 1, Escherichia coli heat-stable toxin, botulinum and tetanus neurotoxins, and S. aureus toxic-shock syndrome toxin. For each, we discuss the information available on its synthesis and structure, mode of action, and contribution to virulence. We also review the role certain toxins have played in unraveling signal pathways in eukaryotic cells and summarize the beneficial uses of toxins and toxoids. Our intent is to illustrate the importance of the analysis of bacterial toxins to both basic and applied sciences. PMID:10221874

Schmitt, C. K.; Meysick, K. C.; O'Brien, A. D.

1999-01-01

275

Cytotoxicity of the Vibrio vulnificus MARTX toxin effector DUF5 is linked to the C2A subdomain.  

PubMed

The multifunctional-autoprocessing repeats-in-toxin (MARTX) toxins are bacterial protein toxins that serve as delivery platforms for cytotoxic effector domains. The domain of unknown function in position 5 (DUF5) effector domain is present in at least six different species' MARTX toxins and as a hypothetical protein in Photorhabdus spp. Its presence increases the potency of the Vibrio vulnificus MARTX toxin in mouse virulence studies, indicating DUF5 directly contributes to pathogenesis. In this work, DUF5 is shown to be cytotoxic when transiently expressed in HeLa cells. DUF5 localized to the plasma membrane dependent upon its C1 domain and the cells become rounded dependent upon its C2 domain. Both full-length DUF5 and the C2 domain caused growth inhibition when expressed in Saccharomyces cerevisiae. A structural model of DUF5 was generated based on the structure of Pasteurella multocida toxin facilitating localization of the cytotoxic activity to a 186 amino acid subdomain termed C2A. Within this subdomain, an alanine scanning mutagenesis revealed aspartate-3721 and arginine-3841 as residues critical for cytotoxicity. These residues were also essential for HeLa cell intoxication when purified DUF5 fused to anthrax toxin lethal factor was delivered cytosolically. Thermal shift experiments indicated that these conserved residues are important to maintain protein structure, rather than for catalysis. The Aeromonas hydrophila MARTX toxin DUF5(Ah) domain was also cytotoxic, while the weakly conserved C1-C2 domains from P. multocida toxin were not. Overall, this study is the first demonstration that DUF5 as found in MARTX toxins has cytotoxic activity that depends on conserved residues in the C2A subdomain. PMID:24935440

Antic, Irena; Biancucci, Marco; Satchell, Karla J F

2014-10-01

276

Swab protocol for rapid laboratory diagnosis of cutaneous anthrax.  

PubMed

The clinical laboratory diagnosis of cutaneous anthrax is generally established by conventional microbiological methods, such as culture and directly straining smears of clinical specimens. However, these methods rely on recovery of viable Bacillus anthracis cells from swabs of cutaneous lesions and often yield negative results. This study developed a rapid protocol for detection of B. anthracis on clinical swabs. Three types of swabs, flocked-nylon, rayon, and polyester, were evaluated by 3 extraction methods, the swab extraction tube system (SETS), sonication, and vortex. Swabs were spiked with virulent B. anthracis cells, and the methods were compared for their efficiency over time by culture and real-time PCR. Viability testing indicated that the SETS yielded greater recovery of B. anthracis from 1-day-old swabs; however, reduced viability was consistent for the 3 extraction methods after 7 days and nonviability was consistent by 28 days. Real-time PCR analysis showed that the PCR amplification was not impacted by time for any swab extraction method and that the SETS method provided the lowest limit of detection. When evaluated using lesion swabs from cutaneous anthrax outbreaks, the SETS yielded culture-negative, PCR-positive results. This study demonstrated that swab extraction methods differ in their efficiency of recovery of viable B. anthracis cells. Furthermore, the results indicated that culture is not reliable for isolation of B. anthracis from swabs at ? 7 days. Thus, we recommend the use of the SETS method with subsequent testing by culture and real-time PCR for diagnosis of cutaneous anthrax from clinical swabs of cutaneous lesions. PMID:23035192

Dauphin, Leslie A; Marston, Chung K; Bhullar, Vinod; Baker, Daniel; Rahman, Mahmudur; Hossain, M Jahangir; Chakraborty, Apurba; Khan, Salah Uddin; Hoffmaster, Alex R

2012-12-01

277

Keeping the Air Clean and Safe: An Anthrax Smoke Detector  

NASA Technical Reports Server (NTRS)

Scientists at work in the Planetary Protection division at NASA s Jet Propulsion Laboratory (JPL) sterilize everything before blasting it to the Red Planet. They take great pains to ensure that all spacecraft are void of bacterial life, especially the microscopic bacteria that can live hundreds of years in their spore states. No one is quite sure what Earthly germs would do on Mars, but scientists agree that it is safest to keep the Martian terrain as undisturbed as possible. Errant Earth germs would also render useless the instruments placed on exploration rovers to look for signs of life, as the life that they registered would be life that came with them from Earth. A team at JPL, headed by Dr. Adrian Ponce, developed a bacterial spore-detection system that uses a simple and robust chemical reaction that visually alerts Planetary Protection crews. It is a simple air filter that traps micron-sized bacterial spores and then submits them to the chemical reaction. When the solution is then viewed under an ultraviolet light, the mixture will glow green if it is contaminated by bacteria. Scientists can then return to the scrubbing and cleaning stages of the sterilization process to remove these harmful bacteria. The detection system is the space-bound equivalent of having your hands checked for cleanliness before being allowed to the table; and although intended to keep terrestrial germs from space, this technology has awesome applications here on Mother Earth. The bacterial spore-detection unit can recognize anthrax and other harmful, spore-forming bacteria and alert people of the impending danger. As evidenced in the anthrax mailings of fall 2001 in the United States, the first sign of anthrax exposure was when people experienced flu-like symptoms, which unfortunately, can take as much as a week to develop after contamination. Anthrax cost 5 people their lives and infected 19 others; and the threat of bioterrorism became a routine concern, with new threats popping up nearly everyday. The attacks threatened the safety that so many Americans took for granted, as the very air that people breathed became suspect. Any building with a circulation system, where large groups congregate, was now a potential target.

2005-01-01

278

Decontamination of Anthrax spores in critical infrastructure and critical assets.  

SciTech Connect

Decontamination of anthrax spores in critical infrastructure (e.g., subway systems, major airports) and critical assets (e.g., the interior of aircraft) can be challenging because effective decontaminants can damage materials. Current decontamination methods require the use of highly toxic and/or highly corrosive chemical solutions because bacterial spores are very difficult to kill. Bacterial spores such as Bacillus anthracis, the infectious agent of anthrax, are one of the most resistant forms of life and are several orders of magnitude more difficult to kill than their associated vegetative cells. Remediation of facilities and other spaces (e.g., subways, airports, and the interior of aircraft) contaminated with anthrax spores currently requires highly toxic and corrosive chemicals such as chlorine dioxide gas, vapor- phase hydrogen peroxide, or high-strength bleach, typically requiring complex deployment methods. We have developed a non-toxic, non-corrosive decontamination method to kill highly resistant bacterial spores in critical infrastructure and critical assets. A chemical solution that triggers the germination process in bacterial spores and causes those spores to rapidly and completely change to much less-resistant vegetative cells that can be easily killed. Vegetative cells are then exposed to mild chemicals (e.g., low concentrations of hydrogen peroxide, quaternary ammonium compounds, alcohols, aldehydes, etc.) or natural elements (e.g., heat, humidity, ultraviolet light, etc.) for complete and rapid kill. Our process employs a novel germination solution consisting of low-cost, non-toxic and non-corrosive chemicals. We are testing both direct surface application and aerosol delivery of the solutions. A key Homeland Security need is to develop the capability to rapidly recover from an attack utilizing biological warfare agents. This project will provide the capability to rapidly and safely decontaminate critical facilities and assets to return them to normal operations as quickly as possible, sparing significant economic damage by re-opening critical facilities more rapidly and safely. Facilities and assets contaminated with Bacillus anthracis (i.e., anthrax) spores can be decontaminated with mild chemicals as compared to the harsh chemicals currently needed. Both the 'germination' solution and the 'kill' solution are constructed of 'off-the-shelf,' inexpensive chemicals. The method can be utilized by directly spraying the solutions onto exposed surfaces or by application of the solutions as aerosols (i.e., small droplets), which can also reach hidden surfaces.

Boucher, Raymond M.; Crown, Kevin K.; Tucker, Mark David; Hankins, Matthew Granholm

2010-05-01

279

Radiolabeled dimethyl branched long chain fatty acid for heart imaging  

DOEpatents

A radiolabeled long chain fatty acid for heart imaging that has dimethyl branching at one of the carbons of the chain which inhibits the extent to which oxidation can occur. The closer to the carboxyl the branching is positioned, the more limited the oxidation, thereby resulting in prolonged retention of the radiolabeled compound in the heart.

Knapp, Jr., Furn F. (Oak Ridge, TN); Goodman, Mark M. (Knoxville, TN); Kirsch, Gilbert (Woippy, FR)

1988-08-16

280

Surveillance and control of anthrax and rabies in wild herbivores and carnivores in Namibia.  

PubMed

Anthrax has been studied intensively in Etosha National Park, Namibia since 1966; in addition, since 1975, mortality due to rabies and all other causes has been recorded, totalling 6,190 deaths. Standard diagnostic procedures demonstrated that at least 811 deaths (13%) were due to anthrax and 115 deaths (2%) were caused by rabies. Of the total number of deaths due to anthrax, 97% occurred in zebra (Equus burchelli), elephant (Loxodonta africana), wildebeest (Connochaetes taurinus) and springbok (Antidorcas marsupialis) while 96% of rabies deaths occurred in kudu (Tragelaphus strepsiceros), jackal (Canis mesomelas), bat-eared fox (Otocyon megalotis) and lion (Panthera leo). Anthrax deaths were highest in the rainy season for zebra, wildebeest and springbok, while elephant mortality peaked during dry seasons. No statistical relationship existed between seasonal rainfall and overall incidence of either anthrax or rabies. Control of anthrax is limited to prophylactic inoculation when rare or endangered species are threatened. Incineration of anthrax carcasses and chemical disinfection of drinking water are not feasible at Etosha. Rabies control consists of the destruction of rabid animals and incineration of their carcasses when possible. PMID:8518440

Berry, H H

1993-03-01

281

Radiolabelling of Antigen and Liposomes for Vaccine Biodistribution Studies  

PubMed Central

A relatively simple and effective method to follow the movement of pharmaceutical preparations such as vaccines in biodistribution studies is to radiolabel the components. Whilst single radiolabelling is common practice, in vaccine systems containing adjuvants the ability to follow both the adjuvant and the antigen is favourable. To this end, we have devised a dual-radiolabelling method whereby the adjuvant (liposomes) is labelled with 3H and the antigen (a subunit protein) with 125I. This model is stable and reproducible; we have shown release of the radiolabels to be negligible over periods of up to 1 week in foetal calf serum at 37 °C. In this paper we describe the techniques which enable the radiolabelling of various components, assessing stability and processing of samples which all for their application in biodistribution studies. Furthermore we provide examples derived from our studies using this model in tuberculosis vaccine biodistribution studies.

Henriksen-Lacey, Malou; Bramwell, Vincent; Perrie, Yvonne

2010-01-01

282

A New Murine Model for Gastrointestinal Anthrax Infection  

PubMed Central

The scientific community has been restricted by the lack of a practical and informative animal model of gastrointestinal infection with vegetative Bacillus anthracis. We herein report the development of a murine model of gastrointestinal anthrax infection by gavage of vegetative Sterne strain of Bacillus anthracis into the complement-deficient A/J mouse strain. Mice infected in this manner developed lethal infections in a dose-dependent manner and died 30 h-5 d following gavage. Histological findings were consistent with penetration and growth of the bacilli within the intestinal villi, with subsequent dissemination into major organs including the spleen, liver, kidney and lung. Blood cultures confirmed anthrax bacteremia in all moribund animals, with approximately 1/3 showing co-infection with commensal enteric organisms. However, no evidence of immune activation was observed during infection. Time-course experiments revealed early compromise of the intestinal epithelium, characterized by villus blunting and ulceration in the ileum and jejunum. A decrease in body temperature was most predictive of near-term lethality. Antibiotic treatment of infected animals 24 h following high-dose bacterial gavage protected all animals, demonstrating the utility of this animal model in evaluating potential therapeutics. PMID:23825096

Xie, Tao; Sun, Chen; Uslu, Kadriye; Auth, Roger D.; Fang, Hui; Ouyang, Weiming; Frucht, David M.

2013-01-01

283

Deterministic models of inhalational anthrax in New Zealand white rabbits.  

PubMed

Computational models describing bacterial kinetics were developed for inhalational anthrax in New Zealand white (NZW) rabbits following inhalation of Ames strain B. anthracis. The data used to parameterize the models included bacterial numbers in the airways, lung tissue, draining lymph nodes, and blood. Initial bacterial numbers were deposited spore dose. The first model was a single exponential ordinary differential equation (ODE) with 3 rate parameters that described mucociliated (physical) clearance, immune clearance (bacterial killing), and bacterial growth. At 36 hours postexposure, the ODE model predicted 1.7×10? bacteria in the rabbit, which agreed well with data from actual experiments (4.0×10? bacteria at 36 hours). Next, building on the single ODE model, a physiological-based biokinetic (PBBK) compartmentalized model was developed in which 1 physiological compartment was the lumen of the airways and the other was the rabbit body (lung tissue, lymph nodes, blood). The 2 compartments were connected with a parameter describing transport of bacteria from the airways into the body. The PBBK model predicted 4.9×10? bacteria in the body at 36 hours, and by 45 hours the model showed all clearance mechanisms were saturated, suggesting the rabbit would quickly succumb to the infection. As with the ODE model, the PBBK model results agreed well with laboratory observations. These data are discussed along with the need for and potential application of the models in risk assessment, drug development, and as a general aid to the experimentalist studying inhalational anthrax. PMID:24527843

Gutting, Bradford

2014-01-01

284

Marine Neurotoxins: Ingestible Toxins.  

PubMed

Fish and shellfish account for a significant portion of food-borne illnesses throughout the world. In general, three classes of diseases result from seafood consumption--intoxication, allergies, and infections. In this review, the authors discuss several seafood-borne toxins, including domoic acid, which acts on the central nervous system. In addition, the authors discuss ciguatoxin-, brevetoxin-, saxitoxin-, tetrodotoxin-, and scombroid-related histamine toxicity, all of which act primarily on the peripheral nervous system. Fish has become a very popular food in the US mostly related to its potential health benefits. Fish is consumed to such a degree that fishing stocks are reportedly at an all time low from what seemed like an endless supply even 30 years ago. One of the most significant threats to human intoxication is the recreational harvest of shellfish, often times located in remote locations where the harvesters are subsistent on fishery resources and have no monitoring in place. The hazard to intoxication is not as common in purchased seafood, which is more stringently regulated, yet still is a serious problem. Most ingestible toxins are thermo-stable and therefore unaffected by cooking, freezing, or salting. Air transport of consumable products throughout the world makes it easy to obtain exotic edibles from far away countries. A seemingly unusual toxin can be more commonly encountered than previously thought and it is important to consider this when evaluating patients. Recognition and treatment of various neurologic symptoms related to seafood ingestion is paramount in today's mobile, gastronomic world. Specific treatments vary with each individual toxin and with the individual's specific reaction to the toxin. Generally, some degree of medical care is required with all ingestible toxin exposure, ranging from simple administration of medication and hydration to ventilatory and cardiovascular support. PMID:14759343

Stommel, Elijah W.; Watters, Michael R.

2004-03-01

285

Tracing the Toxins  

NSDL National Science Digital Library

This activity will help students understand that harmful algal blooms (HABs) can negatively impact organisms in a variety of ways, ranging from cell and tissue damage to death. Students will also realize that toxic blooms are caused by algae. The potent toxins produced by these algae can cause massive fish kills, marine mammal deaths, and human illness. Students will participate in a game based on an Antarctic food web in which their feeding decisions determine their survival in the environment. In follow-up activities, students will look for HABs reported in the media and attempt to trace the path of the toxins through the food chain.

286

Preparation and biodistribution of radiolabeled fullerene C60 nanocrystals  

NASA Astrophysics Data System (ADS)

The present study describes for the first time a procedure for the radiolabeling of fullerene (C60) nanocrystals (nanoC60) with Na 125I, as well as the biodistribution of radiolabeled nanoC60 (125I-nanoC60). The solvent exchange method with tetrahydrofuran was used to make colloidal water suspensions of radiolabeled nanoC60 particles. The radiolabeling procedure with the addition of Na 125I to tetrahydrofuran during dissolution of C60 gave a higher radiochemical yield of radiolabeled nanoC60 particles in comparison to the second option, in which Na 125I was added after C60 was dissolved. Using photon correlation spectroscopy and transmission electron microscopy, 125I-nanoC60 particles were found to have a crystalline structure and a mean diameter of 200-250 nm. The 125I-nanoC60 had a particularly high affinity for human serum albumin, displaying 95% binding efficiency after 1 h. Biodistribution studies of 125I-nanoC60 in rats indicated significant differences in tissue accumulation of 125I-nanoC60 and the radioactive tracer Na 125I. The higher accumulation of radiolabeled nanoC60 was observed in liver and spleen, while accumulation in thyroid, stomach, lungs and intestines was significantly lower in comparison to Na 125I. In addition to being useful for testing the biological distribution of nanoC60, the described radiolabeling procedure might have possible applications in cancer radiotherapy.

Nikoli?, Nadežda; Vranješ-Ðuri?, Sanja; Jankovi?, Drina; Ðoki?, Divna; Mirkovi?, Marija; Bibi?, Nataša; Trajkovi?, Vladimir

2009-09-01

287

PemK Toxin of Bacillus anthracis Is a Ribonuclease  

PubMed Central

Bacillus anthracis genome harbors a toxin-antitoxin (TA) module encoding pemI (antitoxin) and pemK (toxin). This study describes the rPemK as a potent ribonuclease with a preference for pyrimidines (C/U), which is consistent with our previous study that demonstrated it as a translational attenuator. The in silico structural modeling of the PemK in conjunction with the site-directed mutagenesis confirmed the role of His-59 and Glu-78 as an acid-base couple in mediating the ribonuclease activity. The rPemK is shown to form a complex with the rPemI, which is in line with its function as a TA module. This rPemI-rPemK complex becomes catalytically inactive when both the proteins interact in a molar stoichiometry of 1. The rPemI displays vulnerability to proteolysis but attains conformational stability only upon rPemK interaction. The pemI-pemK transcript is shown to be up-regulated upon stress induction with a concomitant increase in the amount of PemK and a decline in the PemI levels, establishing the role of these modules in stress. The artificial perturbation of TA interaction could unleash the toxin, executing bacterial cell death. Toward this end, synthetic peptides are designed to disrupt the TA interaction. The peptides are shown to be effective in abrogating TA interaction in micromolar range in vitro. This approach can be harnessed as a potential antibacterial strategy against anthrax in the future. PMID:20022964

Agarwal, Shivangi; Mishra, Neeraj Kumar; Bhatnagar, Sonika; Bhatnagar, Rakesh

2010-01-01

288

Toxin Plasmids of Clostridium perfringens  

PubMed Central

SUMMARY In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ?16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ?45 kb to ?140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ?35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract. PMID:23699255

Li, Jihong; Adams, Vicki; Bannam, Trudi L.; Miyamoto, Kazuaki; Garcia, Jorge P.; Uzal, Francisco A.; Rood, Julian I.

2013-01-01

289

Anthrax protective antigen interacts with a specific receptor on the surface of CHO-K1 cells.  

PubMed Central

The interaction of protective antigen (PA), a component of the anthrax toxin, with receptors on the Chinese hamster ovary cell line CHO-K1 was characterized. Protective antigen binding at 4 degrees C is highly specific, concentration dependent, saturable (Kd = 0.9 nM), and reversible. Scatchard analysis indicates the presence of a single class of PA binding sites at a concentration of 10,000 +/- 2,000 per cell. Pretreatment of cells with a number of different proteases strongly inhibits PA binding, suggesting that the receptor may be at least partially proteinaceous. Direct chemical cross-linking of radioiodinated PA to the cell surface results in the appearance of a major band exhibiting an apparent molecular mass of 170 kDa, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The appearance of this band is completely inhibited by a 200-fold molar excess of unlabeled PA, indicating a high specificity for this interaction. Our results suggest that a cell surface protein(s) of 85 to 90 kDa is, or constitutes a portion of, a specific receptor for the PA. Images PMID:1909998

Escuyer, V; Collier, R J

1991-01-01

290

EVB Simulations of the Chemical Mechanism of ATP to cAMP Conversion by Anthrax Edema Factor$  

PubMed Central

The two-metal catalysis by the adenylyl cyclase domain of the anthrax edema factor toxin was simulated using the empirical valence bond (EVB) quantum mechanical/molecular mechanical approach. These calculations considered the energetics of the nucleophile deprotonation and a new PO bond formation in the aqueous solution and in the enzyme-substrate complex present in the crystal structure models of the reactant and product state of the reaction. Our calculations support reaction pathway that involves metal-assisted proton transfer from the nucleophile to bulk aqueous solution followed by subsequent formation of an unstable pentavalent intermediate that decomposes into cAMP and pyrophosphate (PPi). This pathway involves ligand exchange in the first solvation sphere of the catalytic metal. The last step of the reaction – the cleavage of the PO bond to PPi – has the highest activation barrier of 13.9 kcal/mol but this barrier height is too close to 12.5 kcal/mol calculated for the nucleophilic attack step to make a definitive conclusion about the rate-limiting step. The calculated reaction mechanism is supported by reasonable agreement between the experimental and calculated catalytic rate constant decrease due to the mutation of the active site lysine 346 to arginine. PMID:23480863

Mones, Letif; Tang, Wei-Jen; Florian, Jan

2014-01-01

291

Effect of Egg Yolk and Phosphatides on Anthrax Infection of Rats and Guinea Pigs.  

National Technical Information Service (NTIS)

Suspension of anthrax spores or vegetative cells in phosphatidyl ethanolamine, or the related phosphatides, phosphatidyl serine and phosphatidyl inositol, markedly reduced the intraperitoneal median lethal dose for guinea pigs and Sprague-Dawley rats, thu...

W. D. Sawyer, R. W. Kuehne, W. Gochenour

1964-01-01

292

Lessons for control of heroin-associated anthrax in Europe from 2009-2010 outbreak case studies, London, UK.  

PubMed

Outbreaks of serious infections associated with heroin use in persons who inject drugs (PWIDs) occur intermittently and require vigilance and rapid reporting of individual cases. Here, we give a firsthand account of the cases in London during an outbreak of heroin-associated anthrax during 2009-2010 in the United Kingdom. This new manifestation of anthrax has resulted in a clinical manifestation distinct from already recognized forms. During 2012-13, additional cases of heroin-associated anthrax among PWIDs in England and other European countries were reported, suggesting that anthrax-contaminated heroin remains in circulation. Antibacterial drugs used for serious soft tissue infection are effective against anthrax, which may lead to substantial underrecognition of this novel illness. The outbreak in London provides a strong case for ongoing vigilance and the use of serologic testing in diagnosis and serologic surveillance schemes to determine and monitor the prevalence of anthrax exposure in the PWID community. PMID:24959910

Abbara, Aula; Brooks, Tim; Taylor, Graham P; Nolan, Marianne; Donaldson, Hugo; Manikon, Maribel; Holmes, Alison

2014-07-01

293

Lessons for Control of Heroin-Associated Anthrax in Europe from 2009-2010 Outbreak Case Studies, London, UK  

PubMed Central

Outbreaks of serious infections associated with heroin use in persons who inject drugs (PWIDs) occur intermittently and require vigilance and rapid reporting of individual cases. Here, we give a firsthand account of the cases in London during an outbreak of heroin-associated anthrax during 2009–2010 in the United Kingdom. This new manifestation of anthrax has resulted in a clinical manifestation distinct from already recognized forms. During 2012–13, additional cases of heroin-associated anthrax among PWIDs in England and other European countries were reported, suggesting that anthrax-contaminated heroin remains in circulation. Antibacterial drugs used for serious soft tissue infection are effective against anthrax, which may lead to substantial underrecognition of this novel illness. The outbreak in London provides a strong case for ongoing vigilance and the use of serologic testing in diagnosis and serologic surveillance schemes to determine and monitor the prevalence of anthrax exposure in the PWID community. PMID:24959910

Abbara, Aula; Brooks, Tim; Taylor, Graham P.; Nolan, Marianne; Donaldson, Hugo; Manikon, Maribel

2014-01-01

294

Call-Tracking Data and the Public Health Response to Bioterrorism-Related Anthrax  

Microsoft Academic Search

After public notification of confirmed cases of bioterrorism-related anthrax, the Centers for Disease Control and Prevention's Emergency Operations Center responded to 11,063 bioterrorism-related telephone calls from October 8 to November 11, 2001. Most calls were inquiries from the public about anthrax vaccines (58.4%), requests for general information on bioterrorism prevention (14.8%), and use of personal protec- tive equipment (12.0%); 882

Joshua A. Mott; Tracee A. Treadwell; Thomas W. Hennessy; Paula A. Rosenberg; Mitchell I. Wolfe; Clive M. Brown; Jay C. Butler

295

Antibody response to a delayed booster dose of anthrax vaccine and botulinum toxoid  

Microsoft Academic Search

We evaluated the prevalence and concentration of serum antibodies 18–24 months after primary inoculation with anthrax and botulinum vaccines, and assessed the reactogenicity and immunogenicity of a significantly delayed booster dose of these vaccines. Five hundred and eight male active-duty military personnel received one, two or three inoculations with anthrax vaccine and\\/or botulinum toxoid in 1990\\/1991 in preparation for Operations

Phillip R Pittman; Dallas Hack; Joseph Mangiafico; Paul Gibbs; Kelly T McKee; Arthur M Friedlander; Maria H Sjogren

2002-01-01

296

Pathology and Pathophysiology of Inhalational Anthrax in a Guinea Pig Model  

PubMed Central

Nonhuman primates (NHPs) and rabbits are the animal models most commonly used to evaluate the efficacy of medical countermeasures against anthrax in support of licensure under the FDA's “Animal Rule.” However, a need for an alternative animal model may arise in certain cases. The development of such an alternative model requires a thorough understanding of the course and manifestation of experimental anthrax disease induced under controlled conditions in the proposed animal species. The guinea pig, which has been used extensively for anthrax pathogenesis studies and anthrax vaccine potency testing, is a good candidate for such an alternative model. This study was aimed at determining the median lethal dose (LD50) of the Bacillus anthracis Ames strain in guinea pigs and investigating the natural history, pathophysiology, and pathology of inhalational anthrax in this animal model following nose-only aerosol exposure. The inhaled LD50 of aerosolized Ames strain spores in guinea pigs was determined to be 5.0 × 104 spores. Aerosol challenge of guinea pigs resulted in inhalational anthrax with death occurring between 46 and 71 h postchallenge. The first clinical signs appeared as early as 36 h postchallenge. Cardiovascular function declined starting at 20 h postexposure. Hematogenous dissemination of bacteria was observed microscopically in multiple organs and tissues as early as 24 h postchallenge. Other histopathologic findings typical of disseminated anthrax included suppurative (heterophilic) inflammation, edema, fibrin, necrosis, and/or hemorrhage in the spleen, lungs, and regional lymph nodes and lymphocyte depletion and/or lymphocytolysis in the spleen and lymph nodes. This study demonstrated that the course of inhalational anthrax disease and the resulting pathology in guinea pigs are similar to those seen in rabbits and NHPs, as well as in humans. PMID:23357384

Savransky, Vladimir; Sanford, Daniel C.; Syar, Emily; Austin, Jamie L.; Tordoff, Kevin P.; Anderson, Michael S.; Stark, Gregory V.; Barnewall, Roy E.; Briscoe, Crystal M.; Lemiale-Bierinx, Laurence; Park, Sukjoon; Ionin, Boris

2013-01-01

297

Information on which to base assessments of risk from environments contaminated with anthrax spores.  

PubMed Central

Although there has been a considerable amount of research conducted into Bacillus anthracis, the causative agent of anthrax, the data are widely disseminated in the scientific literature and are therefore not always easy to assimilate. In view of continuing concern about potential anthrax contamination in environmental materials and sites, this review brings together the currently available information relating to the health hazards from B. anthracis. The relevance of the available information for risk assessment purposes is assessed. PMID:7995358

Watson, A.; Keir, D.

1994-01-01

298

In vitro selection of DNA aptamers to anthrax spores with electrochemiluminescence detection  

Microsoft Academic Search

Systematic evolution of ligands by exponential enrichment (SELEX) was used to select and PCR amplify DNA sequences (aptamers) capable of binding to and detecting nonpathogenic Sterne strain Bacillus anthracis spores. A simplified affinity separation approach was employed, in which autoclaved anthrax spores were used as the separation matrix. An aptamer–magnetic bead-electrochemiluminescence (AM-ECL) sandwich assay scheme was devised for detecting anthrax

John G. Bruno; Johnathan L. Kiel

1999-01-01

299

CYANOBACTERIA AND THEIR TOXINS.  

EPA Science Inventory

Science Questions Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

300

CYANOBACTERIA AND THEIR TOXINS  

EPA Science Inventory

Science Questions Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Cyanobacteria and their highly potent toxins are a significant hazard for human health and ...

301

The bacterial toxin toolkit  

Microsoft Academic Search

Pathogenic bacteria and higher eukaryotes have spent a long time together, leading to a precise understanding of one another's way of functioning. Through rapid evolution, bacteria have engineered increasingly sophisticated weapons to hit exactly where it hurts, interfering with fundamental host functions. However, toxins are not only useful to the bacteria — they have also become an essential asset for

Giampietro Schiavo; F. Gisou van der Goot

2001-01-01

302

CpG oligonucleotides improve the protective immune response induced by the anthrax vaccination of rhesus macaques  

Microsoft Academic Search

Synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs act as immune adjuvants, improving the immune response elicited by co-administered vaccines. Combining CpG ODN with anthrax vaccine adsorbed (AVA, the licensed human vaccine) increased the speed, magnitude and avidity of the resultant anti-anthrax response. The protective activity of these Abs was established by passive transfer to anthrax-challenged mice. The ability of CpG

Dennis M. Klinman; Hang Xie; Stephen F. Little; Debra Currie; Bruce E. Ivins

2004-01-01

303

The Pitfalls of Bioterrorism Preparedness: the Anthrax and Smallpox Experiences  

PubMed Central

Bioterrorism preparedness programs have contributed to death, illness, and waste of public health resources without evidence of benefit. Several deaths and many serious illnesses have resulted from the smallpox vaccination program; yet there is no clear evidence that a threat of smallpox exposure ever existed. The anthrax spores released in 2001 have been linked to secret US military laboratories—the resultant illnesses and deaths might not have occurred if those laboratories were not in operation. The present expansion of bioterrorism preparedness programs will continue to squander health resources, increase the dangers of accidental or purposeful release of dangerous pathogens, and further undermine efforts to enforce international treaties to ban biological and chemical weapons. The public health community should acknowledge the substantial harm that bioterrorism preparedness has already caused and develop mechanisms to increase our public health resources and to allocate them to address the world’s real health needs. PMID:15451727

Cohen, Hillel W.; Gould, Robert M.; Sidel, Victor W.

2004-01-01

304

Spatial analysis of an anthrax outbreak in Saskatchewan, 2006  

PubMed Central

An outbreak of anthrax in Saskatchewan in 2006 affected more than 800 animals at 150 locations. The purpose of this study was to assess the spatial and temporal patterns among the cases to determine if there were any significant trends associated with this outbreak. Case and population data were first analyzed for each individual farm location and then again as aggregate data per rural municipality using spatial and spatiotemporal statistical methods such as Oden’s Ipop, Cuzick-Edwards’ test, spatial scan test, and other mapping techniques. East central Saskatchewan was identified as a primary high risk area, particularly during July 2006. The results of the study led to the conclusion that within this high-risk region, flooding in spring followed by hot and dry conditions could have been a factor in the development of the outbreak. PMID:20885827

Epp, Tasha; Argue, Connie; Waldner, Cheryl; Berke, Olaf

2010-01-01

305

Ante- and postmortem diagnostic techniques for anthrax: rethinking pathogen exposure and the geographic extent of the disease in wildlife.  

PubMed

Although antemortem approaches in wildlife disease surveillance are common for most zoonoses, they have been used infrequently in anthrax surveillance. Classically, anthrax is considered a disease with extremely high mortality. This is because anthrax outbreaks are often detected ex post facto through wildlife or livestock fatalities or spillover transmission to humans. As a result, the natural prevalence of anthrax infection in animal populations is largely unknown. However, in the past 20 yr, antemortem serologic surveillance in wildlife has indicated that not all species exposed succumb to infection, and anthrax exposure may be more widespread than originally appreciated. These studies brought about a multitude of new questions, many of which can be addressed by increased antemortem serologic surveillance in wildlife populations. To fully understand anthrax transmission dynamics and geographic extent, it is important to identify exposure in wildlife hosts and associated factors and, in turn, understand how these influences may drive environmental reservoir dynamics and concurrent disease risk in livestock and humans. Here we review our current understanding of the serologic response to anthrax among wildlife hosts and serologic diagnostic assays used to augment traditional postmortem anthrax surveillance strategies. We also provide recommendations for the use of serology and sentinel species surveillance approaches in anthrax research and management. PMID:24502707

Bagamian, Karoun H; Alexander, Kathleen A; Hadfield, Ted L; Blackburn, Jason K

2013-10-01

306

Preparation and characterization of cobalt-substituted anthrax lethal factor  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Cobalt-substituted anthrax lethal factor (CoLF) is highly active. Black-Right-Pointing-Pointer CoLF can be prepared by bio-assimilation and direct exchange. Black-Right-Pointing-Pointer Lethal factor binds cobalt tightly. Black-Right-Pointing-Pointer The electronic spectrum of CoLF reveals penta-coordination. Black-Right-Pointing-Pointer Interaction of CoLF with thioglycolic acid follows a 2-step mechanism. -- Abstract: Anthrax lethal factor (LF) is a zinc-dependent endopeptidase involved in the cleavage of mitogen-activated protein kinase kinases near their N-termini. The current report concerns the preparation of cobalt-substituted LF (CoLF) and its characterization by electronic spectroscopy. Two strategies to produce CoLF were explored, including (i) a bio-assimilation approach involving the cultivation of LF-expressing Bacillus megaterium cells in the presence of CoCl{sub 2}, and (ii) direct exchange by treatment of zinc-LF with CoCl{sub 2}. Independent of the method employed, the protein was found to contain one Co{sup 2+} per LF molecule, and was shown to be twice as active as its native zinc counterpart. The electronic spectrum of CoLF suggests the Co{sup 2+} ion to be five-coordinate, an observation similar to that reported for other Co{sup 2+}-substituted gluzincins, but distinct from that documented for the crystal structure of native LF. Furthermore, spectroscopic studies following the exposure of CoLF to thioglycolic acid (TGA) revealed a sequential mechanism of metal removal from LF, which likely involves the formation of an enzyme: Co{sup 2+}:TGA ternary complex prior to demetallation of the active site. CoLF reported herein constitutes the first spectroscopic probe of LF's active site, which may be utilized in future studies to gain further insight into the enzyme's mechanism and inhibitor interactions.

Saebel, Crystal E.; Carbone, Ryan; Dabous, John R.; Lo, Suet Y. [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada)] [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada); Siemann, Stefan, E-mail: ssiemann@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada)] [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada)

2011-12-09

307

Monitoring Method of Cow Anthrax Based on Gis and Spatial Statistical Analysis  

NASA Astrophysics Data System (ADS)

Geographic information system (GIS) is a computer application system, which possesses the ability of manipulating spatial information and has been used in many fields related with the spatial information management. Many methods and models have been established for analyzing animal diseases distribution models and temporal-spatial transmission models. Great benefits have been gained from the application of GIS in animal disease epidemiology. GIS is now a very important tool in animal disease epidemiological research. Spatial analysis function of GIS can be widened and strengthened by using spatial statistical analysis, allowing for the deeper exploration, analysis, manipulation and interpretation of spatial pattern and spatial correlation of the animal disease. In this paper, we analyzed the cow anthrax spatial distribution characteristics in the target district A (due to the secret of epidemic data we call it district A) based on the established GIS of the cow anthrax in this district in combination of spatial statistical analysis and GIS. The Cow anthrax is biogeochemical disease, and its geographical distribution is related closely to the environmental factors of habitats and has some spatial characteristics, and therefore the correct analysis of the spatial distribution of anthrax cow for monitoring and the prevention and control of anthrax has a very important role. However, the application of classic statistical methods in some areas is very difficult because of the pastoral nomadic context. The high mobility of livestock and the lack of enough suitable sampling for the some of the difficulties in monitoring currently make it nearly impossible to apply rigorous random sampling methods. It is thus necessary to develop an alternative sampling method, which could overcome the lack of sampling and meet the requirements for randomness. The GIS computer application software ArcGIS9.1 was used to overcome the lack of data of sampling sites.Using ArcGIS 9.1 and GEODA to analyze the cow anthrax spatial distribution of district A. we gained some conclusions about cow anthrax' density: (1) there is a spatial clustering model. (2) there is an intensely spatial autocorrelation. We established a prediction model to estimate the anthrax distribution based on the spatial characteristic of the density of cow anthrax. Comparing with the true distribution, the prediction model has a well coincidence and is feasible to the application. The method using a GIS tool facilitates can be implemented significantly in the cow anthrax monitoring and investigation, and the space statistics - related prediction model provides a fundamental use for other study on space-related animal diseases.

Li, Lin; Yang, Yong; Wang, Hongbin; Dong, Jing; Zhao, Yujun; He, Jianbin; Fan, Honggang

308

Radiolabelled probes for imaging of atherosclerotic plaques  

PubMed Central

Cardiovascular disease is the leading cause of death worldwide. Unstable atherosclerotic plaques are prone to rupture followed by thrombus formation, vessel stenosis, and occlusion and frequently lead to acute myocardial infarction and brain infarction. As such, unstable plaques represent an important diagnostic target in clinical settings and the specific diagnosis of unstable plaques would enable preventive treatments for cardiovascular disease. To date, various imaging methods such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and intravascular ultrasound (IVUS) have been widely used clinically. Although these methods have advantages in terms of spatial resolution and the ability to make detailed identification of morphological alterations such as calcifications and vessel stenosis, these techniques require skill or expertise to discriminate plaque instability, which is essential for early diagnosis and treatment and can present difficulties for quantitative estimation. On the other hand, nuclear imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) can noninvasively collect quantitative information on the expression levels of functional molecules and metabolic activities in vivo and thus provide functional diagnoses of unstable plaques with high sensitivity. Specifically, unstable plaques are characterized by an abundance of invasive inflammatory cells (macrophages), increased oxidative stress that increases oxidized LDL and its receptor expressed on cells in the lesions, increased occurrence of apoptosis of macrophages and other cells involved in disease progression, increased protease expression and activity, and finally thrombus formation triggered by plaque rupture, which is the most important mechanism leading to the onset of infarctions and ischemic sudden death. Therefore, these characteristics can all be targets for molecular imaging by PET and SPECT. In this paper, we review the present state and future of radiolabelled probes that have been developed for detecting atherosclerotic unstable plaques with nuclear imaging techniques. PMID:23145360

Temma, Takashi; Saji, Hideo

2012-01-01

309

Toxins of Amanita phalloides.  

PubMed

The most poisonous mushroom toxins are produced by Amanita phalloides (death cap). The occurrence and chemistry of three groups of toxins (amatoxins, phallotoxins and virotoxins) are summarized. The concentration and distribution of toxins in certain species are variable, with the young fruit body containing lower, and the well-developed fungus higher concentrations, but there is a high variability among specimens collected in the same region. Regarding phallotoxins, the volva (the ring) is the most poisonous. The most important biochemical effect of amatoxins is the inhibition of RNA polymerases (especially polymerase II). This interaction leads to a tight complex and the inhibition is of a non-competitive type. Non-mammalian polymerases show little sensitivity to amanitins. The amatoxins cause necrosis of the liver, also partly in the kidney, with the cellular changes causing the fragmentation and segregation of all nuclear components. Various groups of somatic cells of emanation resistance have been isolated, including from a mutant of Drosophila melanogaster. The phallotoxins stimulate the polymerization of G-actin and stabilize the F-actin filaments. The interaction of phallotoxins occurs via the small, 15-membered ring, on the left side of the spatial formula. The symptoms of human poisoning and the changes in toxin concentrations in different organs are summarized. Conventional therapy includes: (1) stabilization of patient's condition with the correction of hypoglycaemia and electrolytes; (2) decontamination; and (3) chemotherapy with different compounds. Finally, certain antagonists and protective compounds are reviewed, bearing in mind that today these have more of a theoretical than a practical role. PMID:9604278

Vetter, J

1998-01-01

310

Monte Carlo N-particle simulation of neutron-based sterilisation of anthrax contamination  

PubMed Central

Objective To simulate the neutron-based sterilisation of anthrax contamination by Monte Carlo N-particle (MCNP) 4C code. Methods Neutrons are elementary particles that have no charge. They are 20 times more effective than electrons or ?-rays in killing anthrax spores on surfaces and inside closed containers. Neutrons emitted from a 252Cf neutron source are in the 100 keV to 2 MeV energy range. A 2.5 MeV D–D neutron generator can create neutrons at up to 1013 n s?1 with current technology. All these enable an effective and low-cost method of killing anthrax spores. Results There is no effect on neutron energy deposition on the anthrax sample when using a reflector that is thicker than its saturation thickness. Among all three reflecting materials tested in the MCNP simulation, paraffin is the best because it has the thinnest saturation thickness and is easy to machine. The MCNP radiation dose and fluence simulation calculation also showed that the MCNP-simulated neutron fluence that is needed to kill the anthrax spores agrees with previous analytical estimations very well. Conclusion The MCNP simulation indicates that a 10 min neutron irradiation from a 0.5 g 252Cf neutron source or a 1 min neutron irradiation from a 2.5 MeV D–D neutron generator may kill all anthrax spores in a sample. This is a promising result because a 2.5 MeV D–D neutron generator output >1013 n s?1 should be attainable in the near future. This indicates that we could use a D–D neutron generator to sterilise anthrax contamination within several seconds. PMID:22573293

Liu, B; Xu, J; Liu, T; Ouyang, X

2012-01-01

311

Monitoring anthrax vaccine safety in US military service members on active duty: surveillance of 1998 hospitalizations in temporal association with anthrax immunization  

Microsoft Academic Search

We compared 1998 hospitalizations in active-duty US military personnel for possible temporal association with anthrax immunization. Immunization, demographic, and hospitalization data were analyzed using Cox proportional hazards modeling for hospitalization within 42 days of vaccination. Discharge diagnoses were aggregated into 14 International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) categories. Approximately 11% of subjects received one or more doses

Paul A. Sato; Robert J. Reed; Tyler C. Smith; Linda Wang

2002-01-01

312

Pore formation by Cry toxins.  

PubMed

Bacillus thuringiensis (Bt) bacteria produce insecticidal Cry and Cyt proteins used in the biological control of different insect pests. In this review, we will focus on the 3d-Cry toxins that represent the biggest group of Cry proteins and also on Cyt toxins. The 3d-Cry toxins are pore-forming toxins that induce cell death by forming ionic pores into the membrane of the midgut epithelial cells in their target insect. The initial steps in the mode of action include ingestion of the protoxin, activation by midgut proteases to produce the toxin fragment and the interaction with the primary cadherin receptor. The interaction of the monomeric CrylA toxin with the cadherin receptor promotes an extra proteolytic cleavage, where helix alpha-1 of domain I is eliminated and the toxin oligomerization is induced, forming a structure of 250 kDa. The oligomeric structure binds to a secondary receptor, aminopeptidase N or alkaline phosphatase. The secondary receptor drives the toxin into detergent resistant membrane microdomains formingpores that cause osmotic shock, burst of the midgut cells and insect death. Regarding to Cyt toxins, these proteins have a synergistic effect on the toxicity of some Cry toxins. Cyt proteins are also proteolytic activated in the midgut lumen of their target, they bind to some phospholipids present in the mosquito midgut cells. The proposed mechanism of synergism between Cry and Cyt toxins is that Cyt1Aa function as a receptor for Cry toxins. The Cyt1A inserts into midgut epithelium membrane and exposes protein regions that are recognized by Cry11Aa. It was demonstrated that this interaction facilitates the oligomerization of Cry11Aa and also its pore formation activity. PMID:20687486

Soberón, Mario; Pardo, Liliana; Muñóz-Garay, Carlos; Sánchez, Jorge; Gómez, Isabel; Porta, Helena; Bravo, Alejandra

2010-01-01

313

Disease-enhancing antibodies improve the efficacy of bacterial toxin-neutralizing antibodies.  

PubMed

During infection, humoral immunity produces a polyclonal response with various immunoglobulins recognizing different epitopes within the microbe or toxin. Despite this diverse response, the biological activity of an antibody (Ab) is usually assessed by the action of a monoclonal population. We demonstrate that a combination of monoclonal antibodies (mAbs) that are individually disease enhancing or neutralizing to Bacillus anthracis protective antigen (PA), a component of anthrax toxin, results in significantly augmented protection against the toxin. This boosted protection is Fc gamma receptor (Fc?R) dependent and involves the formation of stoichiometrically defined mAb-PA complexes that requires immunoglobulin bivalence and simultaneous interaction between PA and the two mAbs. The formation of these mAb-PA complexes inhibits PA oligomerization, resulting in protection. These data suggest that functional assessments of single Abs may inaccurately predict how the same Abs will operate in polyclonal preparations and imply that potentially therapeutic mAbs may be overlooked in single Ab screens. PMID:23601104

Chow, Siu-Kei; Smith, Cameron; MacCarthy, Thomas; Pohl, Mary Ann; Bergman, Aviv; Casadevall, Arturo

2013-04-17

314

Evidence of Local Persistence of Human Anthrax in the Country of Georgia Associated with Environmental and Anthropogenic Factors  

PubMed Central

Background Anthrax is a soil-borne disease caused by the bacterium Bacillus anthracis and is considered a neglected zoonosis. In the country of Georgia, recent reports have indicated an increase in the incidence of human anthrax. Identifying sub-national areas of increased risk may help direct appropriate public health control measures. The purpose of this study was to evaluate the spatial distribution of human anthrax and identify environmental/anthropogenic factors associated with persistent clusters. Methods/Findings A database of human cutaneous anthrax in Georgia during the period 2000–2009 was constructed using a geographic information system (GIS) with case data recorded to the community location. The spatial scan statistic was used to identify persistence of human cutaneous anthrax. Risk factors related to clusters of persistence were modeled using a multivariate logistic regression. Areas of persistence were identified in the southeastern part of the country. Results indicated that the persistence of human cutaneous anthrax showed a strong positive association with soil pH and urban areas. Conclusions/Significance Anthrax represents a persistent threat to public and veterinary health in Georgia. The findings here showed that the local level heterogeneity in the persistence of human cutaneous anthrax necessitates directed interventions to mitigate the disease. High risk areas identified in this study can be targeted for public health control measures such as farmer education and livestock vaccination campaigns. PMID:24040426

Kracalik, Ian T.; Malania, Lile; Tsertsvadze, Nikoloz; Manvelyan, Julietta; Bakanidze, Lela; Imnadze, Paata; Tsanava, Shota; Blackburn, Jason K.

2013-01-01

315

Rapid generation of an anthrax immunotherapeutic from goats using a novel non-toxic muramyl dipeptide adjuvant  

Microsoft Academic Search

BACKGROUND: There is a clear need for vaccines and therapeutics for potential biological weapons of mass destruction and emerging diseases. Anthrax, caused by the bacterium Bacillus anthracis, has been used as both a biological warfare agent and bioterrorist weapon previously. Although antibiotic therapy is effective in the early stages of anthrax infection, it does not have any effect once exposed

Cassandra D Kelly; Chris O'Loughlin; Frank B Gelder; Johnny W Peterson; Laurie E Sower; Nick M Cirino

2007-01-01

316

Vaccine Protection against Bacillus cereus-Mediated Respiratory Anthrax-Like Disease in Mice  

PubMed Central

Bacillus cereus strains harboring a pXO1-like virulence plasmid cause respiratory anthrax-like disease in humans, particularly in welders. We developed mouse models for intraperitoneal as well as aerosol challenge with spores of B. cereus G9241, harboring pBCXO1 and pBC218 virulence plasmids. Compared to wild-type B. cereus G9241, spores with a deletion of the pBCXO1-carried protective antigen gene (pagA1) were severely attenuated, whereas spores with a deletion of the pBC218-carried protective antigen homologue (pagA2) were not. Anthrax vaccine adsorbed (AVA) immunization raised antibodies that bound and neutralized the pagA1-encoded protective antigen (PA1) but not the PA2 orthologue encoded by pagA2. AVA immunization protected mice against a lethal challenge with spores from B. cereus G9241 or B. cereus Elc4, a strain that had been isolated from a fatal case of anthrax-like disease. As the pathogenesis of B. cereus anthrax-like disease in mice is dependent on pagA1 and PA-neutralizing antibodies provide protection, AVA immunization may also protect humans from respiratory anthrax-like death. PMID:23319564

Oh, So-Young; Maier, Hannah; Schroeder, Jay; Richter, G. Stefan; Elli, Derek; Musser, James M.; Quenee, Lauriane E.; Missiakas, Dominique M.

2013-01-01

317

An adenovirus-vectored nasal vaccine confers rapid and sustained protection against anthrax in a single-dose regimen.  

PubMed

Bacillus anthracis is the causative agent of anthrax, and its spores have been developed into lethal bioweapons. To mitigate an onslaught from airborne anthrax spores that are maliciously disseminated, it is of paramount importance to develop a rapid-response anthrax vaccine that can be mass administered by nonmedical personnel during a crisis. We report here that intranasal instillation of a nonreplicating adenovirus vector encoding B. anthracis protective antigen could confer rapid and sustained protection against inhalation anthrax in mice in a single-dose regimen in the presence of preexisting adenovirus immunity. The potency of the vaccine was greatly enhanced when codons of the antigen gene were optimized to match the tRNA pool found in human cells. In addition, an adenovirus vector encoding lethal factor can confer partial protection against inhalation anthrax and might be coadministered with a protective antigen-based vaccine. PMID:23100479

Zhang, Jianfeng; Jex, Edward; Feng, Tsungwei; Sivko, Gloria S; Baillie, Leslie W; Goldman, Stanley; Van Kampen, Kent R; Tang, De-chu C

2013-01-01

318

An Adenovirus-Vectored Nasal Vaccine Confers Rapid and Sustained Protection against Anthrax in a Single-Dose Regimen  

PubMed Central

Bacillus anthracis is the causative agent of anthrax, and its spores have been developed into lethal bioweapons. To mitigate an onslaught from airborne anthrax spores that are maliciously disseminated, it is of paramount importance to develop a rapid-response anthrax vaccine that can be mass administered by nonmedical personnel during a crisis. We report here that intranasal instillation of a nonreplicating adenovirus vector encoding B. anthracis protective antigen could confer rapid and sustained protection against inhalation anthrax in mice in a single-dose regimen in the presence of preexisting adenovirus immunity. The potency of the vaccine was greatly enhanced when codons of the antigen gene were optimized to match the tRNA pool found in human cells. In addition, an adenovirus vector encoding lethal factor can confer partial protection against inhalation anthrax and might be coadministered with a protective antigen-based vaccine. PMID:23100479

Jex, Edward; Feng, Tsungwei; Sivko, Gloria S.; Baillie, Leslie W.; Goldman, Stanley; Van Kampen, Kent R.; Tang, De-chu C.

2013-01-01

319

Emerging role of radiolabeled nanoparticles as an effective diagnostic technique  

PubMed Central

Nanomedicine is emerging as a promising approach for diagnostic applications. Nanoparticles are structures in the nanometer size range, which can present different shapes, compositions, charges, surface modifications, in vitro and in vivo stabilities, and in vivo performances. Nanoparticles can be made of materials of diverse chemical nature, the most common being metals, metal oxides, silicates, polymers, carbon, lipids, and biomolecules. Nanoparticles exist in various morphologies, such as spheres, cylinders, platelets, and tubes. Radiolabeled nanoparticles represent a new class of agent with great potential for clinical applications. This is partly due to their long blood circulation time and plasma stability. In addition, because of the high sensitivity of imaging with radiolabeled compounds, their use has promise of achieving accurate and early diagnosis. This review article focuses on the application of radiolabeled nanoparticles in detecting diseases such as cancer and cardiovascular diseases and also presents an overview about the formulation, stability, and biological properties of the nanoparticles used for diagnostic purposes. PMID:22809406

2012-01-01

320

In vitro binding of anthrax protective antigen on bacteriophage T4 capsid surface through Hoc-capsid interactions: A strategy for efficient display of large full-length proteins  

SciTech Connect

An in vitro binding system is described to display large full-length proteins on bacteriophage T4 capsid surface at high density. The phage T4 icosahedral capsid features 155 copies of a nonessential highly antigenic outer capsid protein, Hoc, at the center of each major capsid protein hexon. Gene fusions were engineered to express the 83-kDa protective antigen (PA) from Bacillus anthracis fused to the N-terminus of Hoc and the 130-kDa PA-Hoc protein was expressed in Escherichia coli and purified. The purified PA-Hoc was assembled in vitro on hoc {sup -} phage particles. Binding was specific, stable, and of high affinity. This defined in vitro system allowed manipulation of the copy number of displayed PA and imposed no significant limitation on the size of the displayed antigen. In contrast to in vivo display systems, the in vitro approach allows all the capsid binding sites to be occupied by the 130-kDa PA-Hoc fusion protein. The PA-T4 particles were immunogenic in mice in the absence of an adjuvant, eliciting strong PA-specific antibodies and anthrax lethal toxin neutralizing antibodies. The in vitro display on phage T4 offers a novel platform for potential construction of customized vaccines against anthrax and other infectious diseases.

Shivachandra, Sathish B. [Department of Biology, 103 McCort Ward Hall, Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064 (United States); Rao, Mangala [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Janosi, Laszlo [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Sathaliyawala, Taheri [Department of Biology, 103 McCort Ward Hall, Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064 (United States); Matyas, Gary R. [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Alving, Carl R. [Division of Retrovirology, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 (United States); Leppla, Stephen H. [Bacterial Toxins and Therapeutics Section, National Institute of Allergy and Infectious Diseases, NIH, 30 Convent Dr., Bethesda, MD 20892 (United States); Rao, Venigalla B. [Department of Biology, 103 McCort Ward Hall, Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064 (United States)]. E-mail: rao@cua.edu

2006-02-05

321

Whole Proteome Analysis of Mouse Lymph Nodes in Cutaneous Anthrax  

PubMed Central

This study aimed to characterize a soluble proteome of popliteal lymph nodes during lymphadenitis induced by intradermal injection of Bacillus anthracis Sterne spores in mice using tandem LC-MS/MS and reverse-phase protein microarray with antibodies specific to epitopes of phosphorylated proteins. More than 380 proteins were detected in the normal intra-nodal lymph, while the infectious process resulted in the profound changes in the protein abundances and appearance of 297 unique proteins. These proteins belong to an array of processes reflecting response to wounding, inflammation and perturbations of hemostasis, innate immune response, coagulation and fibrinolysis, regulation of body fluid levels and vascular disturbance among others. Comparison of lymph and serum revealed 83 common proteins. Also, using 71 antibodies specific to total and phosphorylated forms of proteins we carried initial characterization of circulating lymph phosphoproteome which brought additional information regarding signaling pathways operating in the lymphatics. The results demonstrate that the proteome of intra-nodal lymph serves as a sensitive sentinel of the processes occurring within the lymph nodes during infection. The acute innate response of the lymph nodes to anthrax is accompanied by cellular damage and inflammation with a large number of up- and down-regulated proteins many of which are distinct from those detected in serum. MS data are available via ProteomeXchange with identifier PXD001342. PMID:25329596

Zhou, Weidong; Mueller, Claudius; Liotta, Lance; Popov, Serguei G.

2014-01-01

322

Bangladesh anthrax outbreaks are probably caused by contaminated livestock feed.  

PubMed

In Bangladesh from 1 July to 30 September 2010 there were 104 animal cases of anthrax and 607 associated human cases. This investigation was conducted in Sirajganj district in December 2010, on eight farms where animal cases had occurred. Bacillus anthracis was recovered from soil samples and turbinate bones on six farms. Canonical single nucleotide polymorphism (SNP) analysis showed that all the isolates belonged to the major lineage A, sublineage A.Br.001/002 of China and South East Asia while a multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) with 15 VNTRs demonstrated three unique genotypes. The single nucleotide repeat (SNR) analyses showed two SNR types in 97 out of 99 isolates; nevertheless, due to its higher discriminatory power the presence of two isolates with different SNR-type polymorphisms were detected within two MLVA genotypes. The epidemic occurred during the monsoon season, a time of extensive flooding, suggesting that the source was contaminated feed, not grazing, which is supported by the genetic variance. PMID:22814512

Fasanella, A; Garofolo, G; Hossain, M J; Shamsuddin, M; Blackburn, J K; Hugh-Jones, M

2013-05-01

323

Anthrax and the geochemistry of soils in the contiguous United States  

USGS Publications Warehouse

Soil geochemical data from sample sites in counties that reported occurrences of anthrax in wildlife and livestock since 2000 were evaluated against counties within the same states (MN, MT, ND, NV, OR, SD and TX) that did not report occurrences. These data identified the elements, calcium (Ca), manganese (Mn), phosphorus (P) and strontium (Sr), as having statistically significant differences in concentrations between county type (anthrax occurrence versus no occurrence). Tentative threshold values of the lowest concentrations of each of these elements (Ca = 0.43 wt %, Mn = 142 mg/kg, P = 180 mg/kg and Sr = 51 mg/kg) and average concentrations (Ca = 1.3 wt %, Mn = 463 mg/kg, P = 580 mg/kg and Sr = 170 mg/kg) were identified from anthrax-positive counties as prospective investigative tools in determining whether an outbreak had “potential” or was “likely” at any given geographic location in the contiguous United States.

Griffin, Dale W.; Silvestri, Erin E.; Bowling, Charlena Y.; Boe, Timothy; Smith, David B.; Nichols, Tonya L.

2014-01-01

324

Serologic Surveillance of Anthrax in the Serengeti Ecosystem, Tanzania, 1996-2009  

PubMed Central

Bacillus anthracis, the bacterium that causes anthrax, is responsible for varying death rates among animal species. Difficulties in case detection, hazardous or inaccessible carcasses, and misdiagnosis hinder surveillance. Using case reports and a new serologic assay that enables multispecies comparisons, we examined exposure to and illness caused by B. anthracis in different species in the Serengeti ecosystem in Tanzania during 1996–2009 and the utility of serosurveillance. High seroprevalence among carnivores suggested regular nonfatal exposure. Seropositive wildebeest and buffalo showed that infection was not invariably fatal among herbivores, whereas absence of seropositivity in zebras and frequent detection of fatal cases indicated high susceptibility. Exposure patterns in dogs reflected known patterns of endemicity and provided new information about anthrax in the ecosystem, which indicated the potential of dogs as indicator species. Serosurveillance is a valuable tool for monitoring and detecting anthrax and may shed light on mechanisms responsible for species-specific variability in exposure, susceptibility, and mortality rates. PMID:21392428

Lembo, Tiziana; Auty, Harriet; Beesley, Cari A.; Bessell, Paul; Packer, Craig; Halliday, Jo; Fyumagwa, Robert; Hoare, Richard; Ernest, Eblate; Mentzel, Christine; Mlengeya, Titus; Stamey, Karen; Wilkins, Patricia P.; Cleaveland, Sarah

2011-01-01

325

Lymphocyte receptors for pertussis toxin  

SciTech Connect

We have investigated human T-lymphocyte receptors for pertussis toxin by affinity isolation and photoaffinity labeling procedures. T lymphocytes were obtained from peripheral human blood, surface iodinated, and solubilized in Triton X-100. The iodinated mixture was then passed through pertussis toxin-agarose, and the fractions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autoradiography of the fixed, dried gels revealed several bands in the pertussis toxin-bound fraction that were not observed in fractions obtained from histone or fetuin-agarose. Further investigations employed a photoaffinity labeling reagent, sulfosuccinimidyl 2-(p-azido-salicylamido)-1,3'-dithiopropionate, to identify pertussis toxin receptors in freshly isolated peripheral blood monocytic cells, T lymphocytes, and Jurkat cells. In all three cell systems, the pertussis toxin affinity probe specifically labeled a single protein species with an apparent molecular weight of 70,000 that was not observed when the procedure was performed in the presence of excess unmodified pertussis toxin. A protein comparable in molecular weight to the one detected by the photoaffinity labeling technique was also observed among the species that bound to pertussis toxin-agarose. The results suggest that pertussis toxin may bind to a 70,000-Da receptor in human T lymphocytes.

Clark, C.G.; Armstrong, G.D. (Univ. of Alberta, Edmonton (Canada))

1990-12-01

326

Botulinum toxin: Bioweapon & magic drug  

PubMed Central

Botulinum neurotoxins, causative agents of botulism in humans, are produced by Clostridium botulinum, an anaerobic spore-former Gram positive bacillus. Botulinum neurotoxin poses a major bioweapon threat because of its extreme potency and lethality; its ease of production, transport, and misuse; and the need for prolonged intensive care among affected persons. A single gram of crystalline toxin, evenly dispersed and inhaled, can kill more than one million people. The basis of the phenomenal potency of botulinum toxin is enzymatic; the toxin is a zinc proteinase that cleaves neuronal vesicle associated proteins responsible for acetylcholine release into the neuromuscular junction. As a military or terrorist weapon, botulinum toxin could be disseminated via aerosol or by contamination of water or food supplies, causing widespread casualties. A fascinating aspect of botulinum toxin research in recent years has been development of the most potent toxin into a molecule of significant therapeutic utility. It is the first biological toxin which is licensed for treatment of human diseases. In the late 1980s, Canada approved use of the toxin to treat strabismus, in 2001 in the removal of facial wrinkles and in 2002, the FDA in the United States followed suit. The present review focuses on both warfare potential and medical uses of botulinum neurotoxin. PMID:21149997

Dhaked, Ram Kumar; Singh, Manglesh Kumar; Singh, Padma; Gupta, Pallavi

2010-01-01

327

Peptide antagonists of superantigen toxins  

Microsoft Academic Search

Superantigens produced by Staphylococcus aureus and Streptococcus pyogenes are among the most lethal of toxins. Toxins in this large family trigger an excessive cellular immune response leading to toxic shock. Superantigens are secreted by the bacteria as diverse natural mixtures, a complexity that demands development of broad-spectrum countermeasures. We used a rational approach to design short peptides with homology to

Raymond Kaempfer

2004-01-01

328

Analysis of suspicious powders following the post 9\\/11 anthrax scare  

Microsoft Academic Search

Background  Following the 9\\/11 terrorist attacks, SET Environmental, Inc., a Chicago-based environmental and hazardousmaterials management\\u000a company received a large number of suspicious powders for analysis.\\u000a \\u000a \\u000a \\u000a Methods  Samples of powders were submitted to SET for anthrax screening and\\/or unknown identification (UI). Anthrax screening was performed\\u000a on-site using a ruggedized analytical pathogen identification device (R.A.P.I.D.) (Idaho Technologies, Salt Lake City, UT).\\u000a UI was performed

Brandon Wills; Jerrold B. Leikin; James Rhee; Chad Tameling; Bijan Saeedi

2008-01-01

329

Synthesis of Radiolabeled Fullerenes C60 and C70  

Microsoft Academic Search

The synthesis of radiolabeled C60\\/C70 for potential biochemical tracer studies was carried out. Vaporization under plasma are conditions (˜3000C) of graphite rods impregnated with the C labeled steroid progesterone generates the expected C60\\/C70 mixture. Isolation and characterization of the C-C60 is reported. Interestingly, the C70 had more radioactivity than the C60.

Stephen R. Wilson; Elbert Chin

1996-01-01

330

Heterobifunctional reagents: A new approach to radiolabeling of monoclonal antibodies  

Microsoft Academic Search

The use of bifunctional chelate such as the cyclic anhydride of DTPA for radiolabeling antibodies (Abs) may lead to homopolymerization, and intra- or intermolecular cross-linking, with resulting denaturation and decrease immunoreactivity of Abs. The authors, therefore, investigated the use of heterobifunctional reagents, whereby one group selectively couples to the amino group of the Ab and the other group to the

T. S. T. Wang; A. K. Ng; R. A. Fawwaz; Z. Liu; P. O. Alderson

1985-01-01

331

Chemical and radiochemical considerations in radiolabeling with ?-emitting radionuclides.  

PubMed

A review of chemical and radiochemical factors that must be considered when radiolabeling targeting agents with radionuclides is presented. The review discusses factors that are important in choice of radionuclide and choice of chelation or bonding reagents to use in the development of an ?-emitting radiopharmaceutical. Chemical parameters, such as physical properties and pendant groups for radiolabeling, are reviewed. A major portion of the review outlines the development of chelates and labeling conditions for radiometals, and application of these reagents/conditions to radiometals. Acyclic and macrocyclic chelates containing amine and carboxylic acid coordination groups are highlighted, with examples of bifunctional chelates for biomolecule conjugation. Information is presented on over 60 radiometal-binding chelates. 211At radiolabeling is separated from that of radiometals, and the various reagents used for radiolabeling have been reviewed. Although not all 211At-labeling reagents are reviewed (due to another recent review), nearly 50 reagents studied in the development of pendant groups for labeling with 211At are described. The review also discusses how therapeutic doses of ?-emitting radiopharmaceuticals can be affected by the radionuclide used and how radiation damage to the radiopharmaceutical can be minimized. PMID:22201710

Wilbur, D Scott

2011-07-01

332

Stoichiometric regulation of phytoplankton toxins.  

PubMed

Ecological Stoichiometry theory predicts that the production, elemental structure and cellular content of biomolecules should depend on the relative availability of resources and the elemental composition of their producer organism. We review the extent to which carbon- and nitrogen-rich phytoplankton toxins are regulated by nutrient limitation and cellular stoichiometry. Consistent with theory, we show that nitrogen limitation causes a reduction in the cellular quota of nitrogen-rich toxins, while phosphorus limitation causes an increase in the most nitrogen-rich paralytic shellfish poisoning toxin. In addition, we show that the cellular content of nitrogen-rich toxins increases with increasing cellular N : P ratios. Also consistent with theory, limitation by either nitrogen or phosphorus promotes the C-rich toxin cell quota or toxicity of phytoplankton cells. These observed relationships may assist in predicting and managing toxin-producing phytoplankton blooms. Such a stoichiometric regulation of toxins is likely not restricted to phytoplankton, and may well apply to carbon- and nitrogen-rich secondary metabolites produced by bacteria, fungi and plants. PMID:24712512

Van de Waal, Dedmer B; Smith, Val H; Declerck, Steven A J; Stam, Eva C M; Elser, James J

2014-06-01

333

Immunoproteomically identified GBAA_0345, alkyl hydroperoxide reductase subunit C is a potential target for multivalent anthrax vaccine.  

PubMed

Anthrax is caused by the spore-forming bacterium Bacillus anthracis, which has been used as a weapon for bioterrorism. Although current vaccines are effective, they involve prolonged dose regimens and often cause adverse reactions. High rates of mortality associated with anthrax have made the development of an improved vaccine a top priority. To identify novel vaccine candidates, we applied an immunoproteomics approach. Using sera from convalescent guinea pigs or from human patients with anthrax, we identified 34 immunogenic proteins from the virulent B. anthracis H9401. To evaluate vaccine candidates, six were expressed as recombinant proteins and tested in vivo. Two proteins, rGBAA_0345 (alkyl hydroperoxide reductase subunit C) and rGBAA_3990 (malonyl CoA-acyl carrier protein transacylase), have afforded guinea pigs partial protection from a subsequent virulent-spore challenge. Moreover, combined vaccination with rGBAA_0345 and rPA (protective antigen) exhibited an enhanced ability to protect against anthrax mortality. Finally, we demonstrated that GBAA_0345 localizes to anthrax spores and bacilli. Our results indicate that rGBAA_0345 may be a potential component of a multivalent anthrax vaccine, as it enhances the efficacy of rPA vaccination. This is the first time that sera from patients with anthrax have been used to interrogate the proteome of virulent B. anthracis vegetative cells. PMID:24273028

Kim, Yeon Hee; Kim, Kyung Ae; Kim, Yu-Ri; Choi, Min Kyung; Kim, Hye Kyeong; Choi, Ki Ju; Chun, Jeong-Hoon; Cha, Kiweon; Hong, Kee-Jong; Lee, Na Gyong; Yoo, Cheon-Kwon; Oh, Hee-Bok; Kim, Tae Sung; Rhie, Gi-eun

2014-01-01

334

Screening for anthrax occurrence in soil of flooded rural areas in Poland after rainfalls in spring 2010.  

PubMed

Introduction and objective. Anthrax spores remain viable and infectious in soil for decades. Flood water can percolate towards the surface the spores buried in soil. Moreover, the flood water might transport spores to areas previously unaffected. After the water recedes the spores located on the surface of the ground can be consumed by grazing animals and cause outbreaks of anthrax. Materials and method. Soil samples were collected in areas of Poland most affected by floods in 2010 (Lubelskie, ?wi?tokrzyskie, Podkarpackie and Mazowieckie provinces). After heating with the aim to kill vegetative forms of bacteria, the samples were cultured on PLET agar and the resulted colonies were investigated in terms of motility and presence of anthrax specific chromosomal (SG-749, plcR) and plasmid markers (capB, pagA). Results. In total, 424 spore-forming, aerobically growing isolates were collected from the tested soil samples. Eighty-nine of them were non-motile. All the isolates were negative in PCR for anthrax specific chromosomal and plasmid markers. Conclusions. Spores of B. anthracis that could be related to risk of anthrax outbreaks were not detected in soil samples tested in this study. The negative results presented may not be proof that Poland is country free of anthrax. The results, however, may suggest a relatively low risk of anthrax outbreaks being triggered in the sampled areas. PMID:25292110

Zasada, Aleksandra A; Formi?ska, Kamila; Ogrodnik, Anna; Gierczy?ski, Rafa?; Jagielski, Marek

2014-09-01

335

AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF THREE IMMUNOASSAY TEST KITS FOR ANTHRAX, BOTULINUM TOXIN AND RICIN  

EPA Science Inventory

Immunoassay test kits are based on immunoassay methods, where specific antibodies are used to detect and measure the contaminants of interest. Immunoassay test kits rely on the reaction of a contaminant or antigen with a selective antibody to give a product that can be measures....

336

Multiple Properties of Cl. Botulinum Toxin.  

National Technical Information Service (NTIS)

Testing Cl. botulinum toxin type A at various times after its preparation it was found that the toxin was not always toxic to the same degree for albino mice and guinea pigs. With the aging of toxin, the toxin's titer decreased to a greater extent for mic...

I. N. Morgunov, S. M. Minervin

1966-01-01

337

Translocation-Specific Conformation of Adenylate Cyclase Toxin from Bordetella pertussis Inhibits Toxin-Mediated Hemolysis  

Microsoft Academic Search

Bordetella pertussis adenylate cyclase (AC) toxin belongs to the RTX family of toxins but is the only member with a known catalytic domain. The principal pathophysiologic function of AC toxin appears to be rapid production of intracellular cyclic AMP (cAMP) by insertion of its catalytic domain into target cells (referred to as intoxication). Relative to other RTX toxins, AC toxin

MARY C. GRAY; SANG-JIN LEE; LLOYD S. GRAY; FRANCA R. ZARETZKY; ANGELA S. OTERO; GABOR SZABO; ERIK L. HEWLETT

2001-01-01

338

Chemical toxins that cause seizures.  

PubMed

Seizurogenic chemicals include a variety of toxic agents, including chemical warfare agents, toxic industrial chemicals, and natural toxins. Chemical weapons such as sarin and VX, and pesticides such as parathion and carbaryl cause hyperstimulation of cholinergic receptors and an increase in excitatory neurotransmission. Glutamatergic hyperstimulation can occur after exposure to excitatory amino acid toxins such as the marine toxin domoic acid. Other pesticides such as lindane and strychnine do not affect excitatory neurotransmission directly, but rather, they block the inhibitory regulation of neurotransmission by antagonism of inhibitory GABA and glycine synapses. In this paper, chemicals that cause seizures by a variety of molecular mechanisms and pathways are discussed. PMID:23085523

Jett, David A

2012-12-01

339

Binary Bacterial Toxins: Biochemistry, Biology, and Applications of Common Clostridium and Bacillus Proteins  

PubMed Central

Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic “A-B” paradigm for protein toxins. The binary toxins produced by B. anthracis, B. cereus, C. botulinum, C. difficile, C. perfringens, and C. spiroforme consist of components not physically associated in solution that are linked to various diseases in humans, animals, or insects. The “B” components are synthesized as precursors that are subsequently activated by serine-type proteases on the targeted cell surface and/or in solution. Following release of a 20-kDa N-terminal peptide, the activated “B” components form homoheptameric rings that subsequently dock with an “A” component(s) on the cell surface. By following an acidified endosomal route and translocation into the cytosol, “A” molecules disable a cell (and host organism) via disruption of the actin cytoskeleton, increasing intracellular levels of cyclic AMP, or inactivation of signaling pathways linked to mitogen-activated protein kinase kinases. Recently, B. anthracis has gleaned much notoriety as a biowarfare/bioterrorism agent, and of primary interest has been the edema and lethal toxins, their role in anthrax, as well as the development of efficacious vaccines and therapeutics targeting these virulence factors and ultimately B. anthracis. This review comprehensively surveys the literature and discusses the similarities, as well as distinct differences, between each Clostridium and Bacillus binary toxin in terms of their biochemistry, biology, genetics, structure, and applications in science and medicine. The information may foster future studies that aid novel vaccine and drug development, as well as a better understanding of a conserved intoxication process utilized by various gram-positive, spore-forming bacteria. PMID:15353562

Barth, Holger; Aktories, Klaus; Popoff, Michel R.; Stiles, Bradley G.

2004-01-01

340

Anthrax vaccine: increasing intervals between the first two doses enhances antibody response in humans  

Microsoft Academic Search

The influence of dosing interval on the human antibody response to anthrax vaccine adsorbed (AVA) was evaluated in two retrospective serological studies. In both studies, the interval between the first two doses was 2, 3 or 4 weeks. In the first study, banked sera were selected from 89 at-risk individuals at a mean time of 13 days after the second

Phillip R. Pittman; Joseph A. Mangiafico; Cynthia A. Rossi; Timothy L. Cannon; Paul H. Gibbs; Gerald W. Parker; Arthur M. Friedlander

2000-01-01

341

Analysis of Anthrax and Plague Biowarfare Vaccine Interactions with Human Monocyte-Derived Dendritic Cells1  

Microsoft Academic Search

The anti-biowarfare anthrax and plague vaccines require repeated dosing to achieve adequate protection. To test the hypothesis that this limited immunogenicity results from the nature of vaccine interactions with the host innate immune system, we inves- tigated molecular and cellular interactions between vaccines, dendritic cells (DCs), and T cells and explored the potential for adjuvants (pertussis) to boost induction of

Anna Skowera; Esther C. de Jong; Joost H. N. Schuitemaker; Jennifer S. Allen; Simon C. Wessely; Gareth Griffiths; Martien Kapsenberg; Mark Peakman

342

Rational design of a fluorescent receptor for the recognition of anthrax biomarker dipicolinate.  

PubMed

A new carbazole-2,7-dicarboxamide derivative has been synthesised and has been proved to effectively bind the dipicolinate anion, which is commonly used as an anthrax biomarker. The fluorescent response from this synthetic receptor offers a selective colour change in an organic-aqueous environment that is of valuable analytical use. PMID:23070516

Curiel, David; Sánchez, Guzmán; Más-Montoya, Miriam; Tárraga, Alberto; Molina, Pedro

2012-12-01

343

Anthrax in New Jersey: A Health Education Experience in Bioterrorism Response and Preparedness  

Microsoft Academic Search

The anthrax attack in 2001 created new challenges to health educators working on the response effort in New Jersey. Never before had there been a need for educating a group of people who had been exposed to a biological weapon. Coming on the heels of the catastrophic World Trade Center collapse on September 11, 2001, the New Jersey Department of

Suzanne Miro; Sean G. Kaufman

2005-01-01

344

Early statistical detection of anthrax outbreaks by tracking over-the-counter medication sales  

Microsoft Academic Search

The recent series of anthrax attacks has reinforced the importance of biosurveillance systems for the timely detection of epidemics. This paper describes a statistical framework for monitoring grocery data to detect a large-scale but localized bioterrorism attack. Our system illustrates the potential of data sources that may be more timely than traditional medical and public health data. The system includes

Anna Goldenberg; Galit Shmueli; Richard A. Caruana; Stephen E. Fienberg

2002-01-01

345

Is In Vitro Antibiotic Combination More Effective than Single-Drug Therapy against Anthrax?  

Microsoft Academic Search

Antibiotic combinations are used to enhance antibacterial efficacy and to prevent the development of resistance. We have tested a possible synergistic effect of several antibacterial combinations on Bacillus anthracis. The in vitro activities of antibiotic combinations against two strains of B. anthracis, strain Sterne and the Russian anthrax vaccine strain STi, were tested by the fractional inhibitory concentration (FIC) method,

Abed Athamna; Muhammad Athamna; Aburashed Nura; Eli Shlyakov; Darrin J. Bast; David Farrell; Ethan Rubinstein

2005-01-01

346

The Genome of a Bacillus Isolate Causing Anthrax in Chimpanzees Combines Chromosomal Properties of B.  

E-print Network

of B. cereus with B. anthracis Virulence Plasmids Silke R. Klee1. *, Elzbieta B. Brzuszkiewicz3 of the Bacillus cereus group, whereas two plasmids were identical to the anthrax virulence plasmids pXO1 and pXO2 strain 97-27 and B. cereus E33L than to B. anthracis strains. For the first time we describe the sequence

347

Relationship Between Prepregnancy Anthrax Vaccination and Pregnancy and Birth Outcomes Among US Army Women  

Microsoft Academic Search

Main Outcome Measures Pregnancy and birth rates and adverse birth out- comes. Results Of a total of 4092 women, 3136 received at least 1 dose of the anthrax vac- cine. There was a total of 513 pregnancies, with 385 following at least 1 dose of an- thrax vaccine. The pregnancy rate ratio (before and after adjustment for marital sta- tus,

Andrew R. Wiesen; Christopher T. Littell

2010-01-01

348

Massive outbreak of anthrax in wildlife in the Malilangwe Wildlife Reserve, Zimbabwe  

Microsoft Academic Search

A massive outbreak of anthrax in the wildlife of the Malilangwe Wildlife Reserve in Zimbabwe between August and November 2004 resulted in the death of almost all the reserve's estimated 500 kudu (Tragelaphus strepsiceros). Other species badly affected were nyala (Tragelaphus angasi), bushbuck (Tragelaphus scriptus), waterbuck (Kobus ellipsiprymnus) and roan antelope (Hippotragus equinus), which suffered losses of approximately 68 per

S B. Clegg; P. C. B. Turnbull; C. M. Foggin; P. M. Lindeque

2007-01-01

349

The Rest of the StoryPublic Health, the News, and the 2001 Anthrax Attacks  

Microsoft Academic Search

The 2001 anthrax attacks brought public health into the media spotlight in away unmatched since the AIDS epidemic of the 1980s. This moment presented Americans with opportunities to better understand the strengths and weaknesses of the nation’s public health infrastructure, as well as to better understand the political and policy backgrounds against which this infrastructure operates. The authors systematically examined

Liana Blas Winett; Regina G. Lawrence

2005-01-01

350

Molecular epidemiologic investigation of an anthrax outbreak among heroin users, Europe.  

PubMed

In December 2009, two unusual cases of anthrax were diagnosed in heroin users in Scotland. A subsequent anthrax outbreak in heroin users emerged throughout Scotland and expanded into England and Germany, sparking concern of nefarious introduction of anthrax spores into the heroin supply. To better understand the outbreak origin, we used established genetic signatures that provided insights about strain origin. Next, we sequenced the whole genome of a representative Bacillus anthracis strain from a heroin user (Ba4599), developed Ba4599-specific single-nucleotide polymorphism assays, and genotyped all available material from other heroin users with anthrax. Of 34 case-patients with B. anthracis-positive PCR results, all shared the Ba4599 single-nucleotide polymorphism genotype. Phylogeographic analysis demonstrated that Ba4599 was closely related to strains from Turkey and not to previously identified isolates from Scotland or Afghanistan, the presumed origin of the heroin. Our results suggest accidental contamination along the drug trafficking route through a cutting agent or animal hides used to smuggle heroin into Europe. PMID:22840345

Price, Erin P; Seymour, Meagan L; Sarovich, Derek S; Latham, Jennie; Wolken, Spenser R; Mason, Joanne; Vincent, Gemma; Drees, Kevin P; Beckstrom-Sternberg, Stephen M; Phillippy, Adam M; Koren, Sergey; Okinaka, Richard T; Chung, Wai-Kwan; Schupp, James M; Wagner, David M; Vipond, Richard; Foster, Jeffrey T; Bergman, Nicholas H; Burans, James; Pearson, Talima; Brooks, Tim; Keim, Paul

2012-08-01

351

Bioterrorism-Related Anthrax: International Response by the Centers for Disease Control and Prevention  

Microsoft Academic Search

After reports of the intentional release of Bacillus anthracis in the United States, epidemiologists, laborato- rians, and clinicians around the world were called upon to respond to widespread political and public con- cerns. To respond to inquiries from other countries regarding anthrax and bioterrorism, the Centers for Disease Control and Prevention established an international team in its Emergency Operations Center.

Christina S. Polyak; Jonathan T. Macy; Margarita Irizarry-De La Cruz; James E. Lai; Jay F. McAuliffe; Tanja Popovic; Segaran P. Pillai; Eric D. Mintz

2002-01-01

352

The Critical Role of Pathology in the Investigation of Bioterrorism-Related Cutaneous Anthrax  

PubMed Central

Cutaneous anthrax is a rare zoonotic disease in the United States. The clinical diagnosis traditionally has been established by conventional microbiological methods, such as culture and gram staining. However, these methods often yield negative results when patients have received antibiotics. During the bioterrorism event of 2001, we applied two novel immunohistochemical assays that can detect Bacillus anthracis antigens in skin biopsy samples even after prolonged antibiotic treatment. These assays provided a highly sensitive and specific method for the diagnosis of cutaneous anthrax, and were critical in the early and rapid diagnosis of 8 of 11 cases of cutaneous anthrax during the outbreak investigation. Skin biopsies were obtained from 10 of these 11 cases, and histopathological findings included various degrees of ulceration, hemorrhage, edema, coagulative necrosis, perivascular inflammation, and vasculitis. Serology was also an important investigation tool, but the results required several weeks because of the need to test paired serum specimens. Other tests, including culture, special stains, and polymerase chain reaction assay, were less valuable in the diagnosis and epidemiological investigation of these cutaneous anthrax cases. This report underscores the critical role of pathology in investigating potential bioterrorism events and in guiding epidemiological studies, a role that was clearly demonstrated in 2001 when B. anthracis spores were intentionally released through the United States postal system. PMID:14578189

Shieh, Wun-Ju; Guarner, Jeannette; Paddock, Christopher; Greer, Patricia; Tatti, Kathleen; Fischer, Marc; Layton, Marci; Philips, Michael; Bresnitz, Eddy; Quinn, Conrad P.; Popovic, Tanja; Perkins, Bradley A.; Zaki, Sherif R.

2003-01-01

353

The dissemination of anthrax from imported wool: Kidderminster 1900-14  

PubMed Central

Background: A century ago anthrax was a continuing health risk in the town of Kidderminster. The distribution of cases in people and in animals provides an indication of the routes by which spores were disseminated. The response to these cases provides an insight into attitudes to an occupational and environmental risk at the time and can be compared with responses in more recent times. Aims: To assess the distribution of anthrax cases associated with the use of contaminated wool and to review the response to them. Methods: The area studied was Kidderminster, Worcestershire, England, from 1900 to 1914. Data sources were national records of the Factory Inspectorate and local records from the infirmary, Medical Officer of Health and inquest reports, and county agricultural records, supplemented by contemporary and later review articles. Case reports and summary data were analysed, and discussions and actions taken to improve precautions reviewed. Results: There were 36 cases of anthrax, with five deaths, one of which was the sole case of the internal form of the disease. Cases of cutaneous anthrax were most frequently found in those handling raw wool, but they also occurred in workers at later stages of the spinning process and in people with little or no recorded exposure to contaminated wool. Limited precautionary measures were in place at the start of the study period. Some improvements were made, especially in the treatment of infections, but wool with a high risk of anthrax contamination continued to be used and cases continued to arise. Major changes were made to the disposal of waste and to agricultural practice in contaminated areas to curtail outbreaks in farm animals. Conclusions: The introduction of anthrax as a contaminant of imported wool led not only to cases in the highly exposed groups of workers but also to cases in other members of the population and in farm animals. The measures taken during the study period reduced fatalities from cutaneous anthrax but did not eliminate the disease. Public concern about the cases was muted. PMID:14739375

Carter, T

2004-01-01

354

Cholera Toxin Mechanism of Action  

NSDL National Science Digital Library

This single image file shows the steps of action of cholera toxin, beginning at protein synthesis in the bacteria and proceeding through all of the major known steps of interaction with the host cell.

American Society For Microbiology;

2002-08-29

355

Botulinum toxin in clinical practice  

PubMed Central

Botulinum toxin, the most potent biological toxin, has become a powerful therapeutic tool for a growing number of clinical applications. This review draws attention to new findings about the mechanism of action of botulinum toxin and briefly reviews some of its most frequent uses, focusing on evidence based data. Double blind, placebo controlled studies, as well as open label clinical trials, provide evidence that, when appropriate targets and doses are selected, botulinum toxin temporarily ameliorates disorders associated with excessive muscle contraction or autonomic dysfunction. When injected not more often than every three months, the risk of blocking antibodies is slight. Long term experience with this agent suggests that it is an effective and safe treatment not only for approved indications but also for an increasing number of off-label indications. PMID:15201348

Jankovic, J

2004-01-01

356

Transcytosis of Staphylococcal Superantigen Toxins  

PubMed Central

Staphylococcus aureus produces a set of proteins (e.g., staphylococcal enterotoxin A [SEA], SEB, toxic shock syndrome toxin 1 [TSST-1]) which act both as superantigens (SAgs) and toxins. Although their mode of action as SAgs is well understood, little is known about how they enter the body via the intestine and cause food poisoning. To examine this problem we used an in vitro culture system to study the capacity of class II MHC-negative human intestinal epithelial cells (Caco-2) to transcytose several staphylococcal toxins. We found that Caco-2 cells are capable of dosedependent, facilitated transcytosis of SEB and TSST-1, but not SEA. We extended these studies in vivo in mice by showing that ingested SEB appears in the blood more efficiently than SEA. Our data suggest that these toxins can cross the epithelium in an immunologically intact form. These results may have important implications for the pathogenesis of food poisoning. PMID:9126925

Hamad, Abdel Rahim A.; Marrack, Philippa; Kappler, John W.

1997-01-01

357

Photolabeling of Glu-129 of the S-1 subunit of pertussis toxin with NAD  

SciTech Connect

UV irradiation was shown to induce efficient transfer of radiolabel from nicotinamide-labeled NAD to a recombinant protein (C180 peptide) containing the catalytic region of the S-1 subunit of pertussis toxin. Incorporation of label from (3H-nicotinamide)NAD was efficient (0.5 to 0.6 mol/mol of protein) relative to incorporation from (32P-adenylate)NAD (0.2 mol/mol of protein). Label from (3H-nicotinamide)NAD was specifically associated with Glu-129. Replacement of Glu-129 with glycine or aspartic acid made the protein refractory to photolabeling with (3H-nicotinamide)NAD, whereas replacement of a nearby glutamic acid, Glu-139, with serine did not. Photolabeling of the C180 peptide with NAD is similar to that observed with diphtheria toxin and exotoxin A of Pseudomonas aeruginosa, in which the nicotinamide portion of NAD is transferred to Glu-148 and Glu-553, respectively, in the two toxins. These results implicate Glu-129 of the S-1 subunit as an active-site residue and a potentially important site for genetic modification of pertussis toxin for development of an acellular vaccine against Bordetella pertussis.

Barbieri, J.T.; Mende-Mueller, L.M.; Rappuoli, R.; Collier, R.J. (Medical College of Wisconsin, Milwaukee (USA))

1989-11-01

358

Multigenic Control and Sex Bias in Host Susceptibility to Spore-Induced Pulmonary Anthrax in Mice?†  

PubMed Central

Mechanisms underlying susceptibility to anthrax infection are unknown. Using a phylogenetically diverse panel of inbred mice and spores of Bacillus anthracis Ames, we investigated host susceptibility to pulmonary anthrax. Susceptibility profiles for survival time and organ pathogen load differed across strains, indicating distinct genetic controls. Tissue infection kinetics analysis showed greater systemic dissemination in susceptible DBA/2J (D) mice but a higher terminal bacterial load in resistant BALB/cJ (C) mice. Interestingly, the most resistant strains, C and C57BL/6J (B), demonstrated a sex bias for susceptibility. For example, BALB/cJ females had a significantly higher survival time and required 4-fold more spores for 100% mortality compared to BALB/cJ males. To identify genetic regions associated with differential susceptibility, survival time and extent of organ infection were assessed using mice derived from two susceptibility models: (i) BXD advanced recombinant inbred strains and (ii) F2 offspring generated from polar responding C and D strains. Genome-wide analysis of BXD strain survival identified linkage on chromosomes 5, 6, 9, 11, and 14. Quantitative trait locus (QTL) analysis of the C×DF2 population revealed a significant QTL (designated Rpai1 for resistance to pulmonary anthrax infection, locus 1) for survival time on chromosome 17 and also identified a chromosome 11 locus for lung pathogen burden. The striking difference between genome-wide linkage profiles for these two mouse models of anthrax susceptibility supports our hypothesis that these are multigenic traits. Our data provide the first evidence for a differential sex response to anthrax resistance and further highlight the unlikelihood of a single common genetic contribution for this response across strains. PMID:21628518

Yadav, Jagjit S.; Pradhan, Suman; Kapoor, Renuka; Bangar, Hansraj; Burzynski, Benjamin B.; Prows, Daniel R.; Levin, Linda

2011-01-01

359

Development and Application of Analytical Methods for Marine Toxins.  

E-print Network

??Shellfish accumulate marine toxins from their microalgal diet. The marine toxin tetrodotoxin (TTX) also accumulates in seafood, but via unknown mechanisms. Toxin determinations have traditionally… (more)

McNabb, Paul Simon

2014-01-01

360

ForPeerReview Modeling the structure of mAb 14B7 bound to the anthrax protective  

E-print Network

University, Department of Chemical and Biomolecular Engineering Maynard, Jennifer; University of Minnesota to the Anthrax Protective Antigen Arvind Sivasubramanian,1 Jennifer A. Maynard2 and Jeffrey J. Gray1, 3, 4* 1

Gray, Jeffrey J.

361

Antibody-based biological toxin detection  

SciTech Connect

Fiber optic evanescent fluorosensors are under investigation in our laboratory for the study of drug-receptor interactions for detection of threat agents and antibody-antigen interactions for detection of biological toxins. In a direct competition assay, antibodies against Cholera toxin, Staphylococcus Enterotoxin B or ricin were noncovalently immobilized on quartz fibers and probed with fluorescein isothiocyanate (FITC) - labeled toxins. In the indirect competition assay, Cholera toxin or Botulinum toxoid A was immobilized onto the fiber, followed by incubation in an antiserum or partially purified anti-toxin IgG. These were then probed with FITC-anti-IgG antibodies. Unlabeled toxins competed with labeled toxins or anti-toxin IgG in a dose dependent manner and the detection of the toxins was in the nanomolar range.

Menking, D.E.; Goode, M.T. [Army Edgewood Research, Development and Engineering Center, Aberdeen Proving Ground, MD (United States)

1995-12-01

362

Internal radiation dosimetry for clinical testing of radiolabeled monoclonal antibodies  

SciTech Connect

In gauging the efficacy of radiolabeled monoclonal antibodies in cancer treatment, it is important to know the amount of radiation energy absorbed by tumors and normal tissue per unit administered activity. This paper describes methods for estimating absorbed doses to human tumors and normal tissues, including intraperitoneal tissue surfaces, red marrow, and the intestinal tract from incorporated radionuclides. These methods use the Medical Internal Radiation Dose (MIRD) scheme; however, they also incorporate enhancements designed to solve specific dosimetry problems encountered during clinical studies, such as patient-specific organ masses obtained from computerized tomography (CT) volumetrics, estimates of the dose to tumor masses within normal organs, and multicellular dosimetry for studying dose inhomogeneities in solid tumors. Realistic estimates of absorbed dose are provided within the short time requirements of physicians so that decisions can be made with regard to patient treatment and procurement of radiolabeled antibodies. Some areas in which further research could improve dose assessment are also discussed. 16 refs., 3 figs.

Fisher, D.R.; Durham, J.S.; Hui, T.E.; Hill, R.L.

1990-11-01

363

Circulating lethal toxin decreases the ability of neutrophils to respond to Bacillus anthracis.  

PubMed

Polymorphonuclear leucocytes (PMNs) play a protective role during Bacillus anthracis infection. However, B.?anthracis is able to subvert the PMN response effectively as evidenced by the high mortality rates of anthrax. One major virulence factor produced by B.?anthracis, lethal toxin (LT), is necessary for dissemination in the BSL2 model of mouse infection. While human and mouse PMNs kill vegetative B.?anthracis, short in vitro half-lives of PMNs have made it difficult to determine how or if LT alters their bactericidal function. Additionally, the role of LT intoxication on PMN's ability to migrate to inflammatory signals remains controversial. LF concentrations in both serum and major organs were determined from mice infected with B.?anthracis?Sterne strain at defined stages of infection to guide subsequent administration of purified toxin. Bactericidal activity of PMNs assessed using ex vivo cell culture assays showed significant defects in killing B.?anthracis. In vivo?PMN recruitment to inflammatory stimuli was significantly impaired at 24?h as assessed by real-time analysis of light-producing PMNs within the mouse. The observations described above suggest that LT serves dual functions; it both attenuates accumulation of PMNs at sites of inflammation and impairs PMNs bactericidal activity against vegetative B.?anthracis. PMID:24152301

Weiner, Zachary P; Ernst, Stephen M; Boyer, Anne E; Gallegos-Candela, Maribel; Barr, John R; Glomski, Ian J

2014-04-01

364

Detection of anti-protective antigen salivary IgG antibodies in recipients of the US licensed anthrax vaccine  

Microsoft Academic Search

The immune response of anthrax vaccine recipients is not routinely monitored. For field use, a noninvasive test would be beneficial to evaluate the antibody response of anthrax-vaccinated individuals working within a high-risk area of possible exposure. The aim of this cross-sectional study was to determine whether whole saliva can be used as a surrogate matrix for the detection of 83kDa

Diane R. Bienek; Cheow K. Chang; Mark E. Cohen

2007-01-01

365

Application of radiolabeled tracers to biocatalytic flux analysis.  

PubMed

Radiolabeled tracers can provide valuable information about the structure of and flux distributions in biocatalytic reaction networks. This method derives from prior studies of glucose metabolism in mammalian systems and is implemented by pulsing a culture with a radiolabeled metabolite that can be transported into the cells and subsequently measuring the radioactivity of all network metabolites following separation by liquid chromatography. Intracellular fluxes can be directly determined from the transient radioactivity count data by tracking the depletion of the radiolabeled metabolite and/or the accompanying accumulation of any products formed. This technique differs from previous methods in that it is applied within a systems approach to the problem of flux determination. It has been used for the investigation of the indene bioconversion network expressed in Rhodococcus sp. KY1. Flux estimates obtained by radioactive tracers were confirmed by macroscopic metabolite balancing and showed that indene oxidation in steady state chemostat cultures proceeds primarily through a monooxygenase activity forming (1S,2R)-indan oxide, with no dehydrogenation of trans-(1R,2R)-indandiol. These results confirmed the significance of indan oxide formation and identified the hydrolysis of indan oxide as a key step in maximizing the production of (2R)-indandiol, a chiral precursor of the HIV protease inhibitor, Crixivan. PMID:11559364

Yanagimachi, K S; Stafford, D E; Dexter, A F; Sinskey, A J; Drew, S; Stephanopoulos, G

2001-09-01

366

Changing Patterns of Human Anthrax in Azerbaijan during the Post-Soviet and Preemptive Livestock Vaccination Eras  

PubMed Central

We assessed spatial and temporal changes in the occurrence of human anthrax in Azerbaijan during 1984 through 2010. Data on livestock outbreaks, vaccination efforts, and human anthrax incidence during Soviet governance, post-Soviet governance, preemptive livestock vaccination were analyzed. To evaluate changes in the spatio-temporal distribution of anthrax, we used a combination of spatial analysis, cluster detection, and weighted least squares segmented regression. Results indicated an annual percent change in incidence of +11.95% from 1984 to 1995 followed by declining rate of ?35.24% after the initiation of livestock vaccination in 1996. Our findings also revealed geographic variation in the spatial distribution of reporting; cases were primarily concentrated in the west early in the study period and shifted eastward as time progressed. Over twenty years after the dissolution of the Soviet Union, the distribution of human anthrax in Azerbaijan has undergone marked changes. Despite decreases in the incidence of human anthrax, continued control measures in livestock are needed to mitigate its occurrence. The shifting patterns of human anthrax highlight the need for an integrated “One Health” approach that takes into account the changing geographic distribution of the disease. PMID:25032701

Kracalik, Ian; Abdullayev, Rakif; Asadov, Kliment; Ismayilova, Rita; Baghirova, Mehriban; Ustun, Narmin; Shikhiyev, Mazahir; Talibzade, Aydin; Blackburn, Jason K.

2014-01-01

367

Changing patterns of human anthrax in Azerbaijan during the post-Soviet and preemptive livestock vaccination eras.  

PubMed

We assessed spatial and temporal changes in the occurrence of human anthrax in Azerbaijan during 1984 through 2010. Data on livestock outbreaks, vaccination efforts, and human anthrax incidence during Soviet governance, post-Soviet governance, preemptive livestock vaccination were analyzed. To evaluate changes in the spatio-temporal distribution of anthrax, we used a combination of spatial analysis, cluster detection, and weighted least squares segmented regression. Results indicated an annual percent change in incidence of (+)11.95% from 1984 to 1995 followed by declining rate of -35.24% after the initiation of livestock vaccination in 1996. Our findings also revealed geographic variation in the spatial distribution of reporting; cases were primarily concentrated in the west early in the study period and shifted eastward as time progressed. Over twenty years after the dissolution of the Soviet Union, the distribution of human anthrax in Azerbaijan has undergone marked changes. Despite decreases in the incidence of human anthrax, continued control measures in livestock are needed to mitigate its occurrence. The shifting patterns of human anthrax highlight the need for an integrated "One Health" approach that takes into account the changing geographic distribution of the disease. PMID:25032701

Kracalik, Ian; Abdullayev, Rakif; Asadov, Kliment; Ismayilova, Rita; Baghirova, Mehriban; Ustun, Narmin; Shikhiyev, Mazahir; Talibzade, Aydin; Blackburn, Jason K

2014-07-01

368

Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2009.  

PubMed

These recommendations from the Advisory Committee on Immunization Practices (ACIP) update the previous recommendations for anthrax vaccine adsorbed (AVA) (CDC. Use of anthrax vaccine in the United States: Recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2000;49:1-20; CDC. Use of anthrax vaccine in response to terrorism: supplemental recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2002;51:1024-6) and reflect the status of anthrax vaccine supplies in the United States. This statement 1) provides updated information on anthrax epidemiology; 2) summarizes the evidence regarding the effectiveness and efficacy, immunogenicity, and safety of AVA; 3) provides recommendations for pre-event and preexposure use of AVA; and 4) provides recommendations for postexposure use of AVA. In certain instances, recommendations that did not change were clarified. No new licensed anthrax vaccines are presented. Substantial changes to these recommendations include the following: 1) reducing the number of doses required to complete the pre-event and preexposure primary series from 6 doses to 5 doses, 2) recommending intramuscular rather than subcutaneous AVA administration for preexposure use, 3) recommending AVA as a component of postexposure prophylaxis in pregnant women exposed to aerosolized Bacillus anthracis spores, 4) providing guidance regarding preexposure vaccination of emergency and other responder organizations under the direction of an occupational health program, and 5) recommending 60 days of antimicrobial prophylaxis in conjunction with 3 doses of AVA for optimal protection of previously unvaccinated persons after exposure to aerosolized B. anthracis spores. PMID:20651644

Wright, Jennifer Gordon; Quinn, Conrad P; Shadomy, Sean; Messonnier, Nancy

2010-07-23

369

Intimin, Tir, and Shiga Toxin 1 Do Not Influence Enteropathogenic Responses to Shiga Toxin-Producing Escherichia coli in Bovine Ligated Intestinal Loops  

PubMed Central

Shiga toxin-producing Escherchia coli (STEC) comprises a group of attaching and effacing (A/E) enteric pathogens of animals and humans. Natural and experimental infection of calves with STEC may result in acute enteritis or subclinical infection, depending on serotype- and host-specific factors. To quantify intestinal secretory and inflammatory responses to STEC in the bovine intestine, serotypes that are associated with human disease (O103:H2 and O157:H7) were introduced into ligated mid-ileal loops in gnotobiotic and conventional calves, and fluid accumulation and recruitment of radiolabeled neutrophils were measured after 12 h. STEC serotype O103:H2, but not serotype O157:H7, elicited strong enteropathogenic responses. To determine if the inflammatory response to STEC O103:H2 in calves requires Shiga toxin 1 or intimate bacterial attachment to the intestinal epithelium, defined mutations were made in the stx1, eae, and tir genes. Our data indicate that some STEC induce intestinal inflammatory responses in calves by a mechanism that is independent of A/E-lesion formation, intimin, or Shiga toxin 1. This may have implications for strategies to reduce STEC carriage in cattle. PMID:11796630

Stevens, Mark P.; Marches, Olivier; Campbell, June; Huter, Veronika; Frankel, Gad; Phillips, Alan D.; Oswald, Eric; Wallis, Timothy S.

2002-01-01

370

A Cell-Based Approach for the Biosynthesis/Screening of Cyclic Peptide Libraries against Bacterial Toxins  

SciTech Connect

Available methods for developing and screening small drug-like molecules able to knockout toxins or pathogenic microorganisms have some limitations. In order to be useful, these new methods must provide high-throughput analysis and identify specific binders in a short period of time. To meet this need, we are developing an approach that uses living cells to generate libraries of small biomolecules, which are then screened inside the cell for activity. Our group is using this new, combined approach to find highly specific ligands capable of disabling anthrax Lethal Factor (LF) as proof of principle. Key to our approach is the development of a method for the biosynthesis of libraries of cyclic peptides, and an efficient screening process that can be carried out inside the cell.

Camarero, J A; Kimura, R; Woo, Y; Cantor, J; Steenblock, E

2007-10-24

371

Randomized, double-blind, placebo-controlled, safety and immunogenicity study of 4 formulations of Anthrax Vaccine Adsorbed plus CPG 7909 (AV7909) in healthy adult volunteers.  

PubMed

A new anthrax vaccine that could accelerate the immune response and possibly reduce the number of injections needed for protection would be desirable in a post-exposure setting. This Phase 1 study compared the safety and immunogenicity of 2 IM doses (Days 0 and 14) of 4 formulations of AV7909 (AVA plus CPG 7909) with 2 IM doses of BioThrax(®) (Anthrax Vaccine Adsorbed) and 2 IM doses of saline placebo administered on Days 0 and 14. A total of 105 healthy adults 18-50 years of age were randomized to 1 of 6 study groups: BioThrax (0.5 mL), AV7909 Formulation 1 (0.5 mL AVA+0.5mg CPG 7909), AV7909 Formulation 2 (0.5 mL AVA+0.25mg CPG 7909), AV7909 Formulation 3 (0.25 mL AVA+0.5mg CPG 7909), AV7909 Formulation 4 (0.25 mL AVA+0.25mg CPG 7909), or saline placebo (0.5 mL). All randomized subjects received at least 1 vaccination, and 100 subjects completed the trial. After 2 doses, mean peak normalized toxin neutralizing antibody responses (TNA NF50) in the AV7909 groups were higher than in the BioThrax group. Differences among the 4 AV7909 groups were not statistically significant. Subjects who received AV7909 reached peak titers on Day 28 vs. Day 35 in the BioThrax group. The most common adverse events (AEs) in the BioThrax and AV7909 groups assessed as related to vaccination were injection site reactions. Transient lymphopenia was observed after the first dose in each AV7909 group. Frequencies of injection site and systemic reactions recorded by subjects in diaries for 7 days after each injection were highest with AV7909 Formulation 1. No AEs of special interest (autoimmune events) were observed in the study. Further studies of doses and dosing regimens are planned to assess the immunogenicity and reactogenicity of AV7909. PMID:23701746

Hopkins, Robert J; Daczkowski, Nancy F; Kaptur, Paulina E; Muse, Derek; Sheldon, Eric; LaForce, Craig; Sari, Suha; Rudge, Thomas L; Bernton, Edward

2013-06-26

372

Synthesis and immunochemical evaluation of a non-methylated disaccharide analogue of the anthrax tetrasaccharide.  

PubMed

Anthrax tetrasaccharide is an oligosaccharide expressed at the outermost surface of the Bacillus anthracis spores, featuring three rhamnoses and a rare sugar called anthrose. This motif has now been identified as a plausible component of future human vaccines against anthrax. We report herein the synthesis of a 2-O-demethylated-?-D-anthropyranosyl-(1?3)-?-L-rhamnopyranose disaccharide analogue of this tetrasaccharide from a cyclic sulfate intermediate. This disaccharide conjugated to BSA induces an anti-native tetrasaccharide IgG antibody response when administered in BALB/c mice. Moreover, induced sera bound to native B. anthracis endospores. These results suggest that the disaccharide analogue, easily amenable for a synthetic scale-up, could be used in a glycoconjugate antigen formulation. PMID:23010801

Milhomme, Ophélie; Köhler, Susanne M; Ropartz, David; Lesur, David; Pilard, Serge; Djedaïni-Pilard, Florence; Beyer, Wolfgang; Grandjean, Cyrille

2012-11-14

373

Protocol for real-time PCR identification of anthrax spores from nasal swabs after broth enrichment.  

PubMed

A mass-screening protocol for the diagnosis of anthrax from nasal swabs based on an enrichment step in liquid medium was devised. Incubation for growth was performed in autoclavable vials and racks which allow real-time PCR analysis of sterilized cultures. A dual-color PCR was set up with primers and probes for the chromosomal marker rpoB and the plasmid marker lef. Specific primer and probe sets were designed for the differentiation of Bacillus anthracis from B. cereus and for the differentiation of the Sterne vaccine strain from field isolates and the Ames strain, which was used in the recent anthrax bioterrorist attack. The present protocol thus combines the high specificity and sensitivity of real-time PCR with excellent biosafety and the low hands-on time necessary for the processing of large numbers of samples, which is extremely important during control programs involving the processing of large numbers of samples. PMID:12409358

Oggioni, Marco R; Meacci, Francesca; Carattoli, Alessandra; Ciervo, Alessandra; Orru, Germano; Cassone, Antonio; Pozzi, Gianni

2002-11-01

374

Thioamide Hydroxypyrothiones Supersede Amide Hydroxypyrothiones in Potency Against Anthrax Lethal Factor  

PubMed Central

Anthrax lethal factor (LF) is a critical virulence factor in the pathogenesis of anthrax. A structure-activity relationship (SAR) of potential lethal factor inhibitors (LFi) is presented in which the zinc-binding group (ZBG), linker, and backbone moieties for a series of hydroxypyrone-based compounds were systematically varied. It was found that hydroxypyrothione ZBGs generate more potent inhibitors than hydroxypyrone ZBGs. Furthermore, coupling the hydroxypyrothione to a backbone group via a thioamide bond improves potency when compared to an amide linker. QM/MM studies show that the thioamide bond in these inhibitors allows for the formation of two additional hydrogen bonds with the protein active site. In both types of hydroxypyrothione compounds, ligand efficiencies of 0.29-0.54 kcal mol-1 per heavy atom were achieved. The results highlight the need for a better understanding to optimize the interplay between the ZBG, linker, and backbone to get improved LFi. PMID:19170530

Agrawal, Arpita; de Oliveira, Cesar Augusto F.; Cheng, Yuhui; Jacobsen, Jennifer A.; McCammon, J. Andrew; Cohen, Seth M.

2009-01-01

375

Massive outbreak of anthrax in wildlife in the Malilangwe Wildlife Reserve, Zimbabwe.  

PubMed

A massive outbreak of anthrax in the wildlife of the Malilangwe Wildlife Reserve in Zimbabwe between August and November 2004 resulted in the death of almost all the reserve's estimated 500 kudu (Tragelaphus strepsiceros). Other species badly affected were nyala (Tragelaphus angasi), bushbuck (Tragelaphus scriptus), waterbuck (Kobus ellipsiprymnus) and roan antelope (Hippotragus equinus), which suffered losses of approximately 68 per cent, 48 per cent, 44 per cent and 42 per cent of their populations, respectively. Buffalo (Syncerus caffer) were also badly affected and although their population suffered only a 6 per cent loss, the numbers of deaths ranked second highest after kudu. To the authors' knowledge, this is the first record of anthrax in wildlife in Zimbabwe. PMID:17259452

Clegg, S B; Turnbull, P C B; Foggin, C M; Lindeque, P M

2007-01-27

376

Special Considerations for Prophylaxis for and Treatment of Anthrax in Pregnant and Postpartum Women  

PubMed Central

In August 2012, the Centers for Disease Control and Prevention, in partnership with the Association of Maternal and Child Health Programs, convened a meeting of national subject matter experts to review key clinical elements of anthrax prevention and treatment for pregnant, postpartum, and lactating (P/PP/L) women. National experts in infectious disease, obstetrics, maternal fetal medicine, neonatology, pediatrics, and pharmacy attended the meeting, as did representatives from professional organizations and national, federal, state, and local agencies. The meeting addressed general principles of prevention and treatment for P/PP/L women, vaccines, antimicrobial prophylaxis and treatment, clinical considerations and critical care issues, antitoxin, delivery concerns, infection control measures, and communication. The purpose of this meeting summary is to provide updated clinical information to health care providers and public health professionals caring for P/PP/L women in the setting of a bioterrorist event involving anthrax. PMID:24457117

Zotti, Marianne E.; Creanga, Andreea A.; Misegades, Lara K.; Wako, Etobssie; Treadwell, Tracee A.; Messonnier, Nancy E.; Jamieson, Denise J.

2014-01-01

377

A Supramolecular Sensing Platform for Phosphate Anions and an Anthrax Biomarker in a Microfluidic Device  

E-print Network

Abstract: A supramolecular platform based on self-assembled monolayers (SAMs) has been implemented in a microfluidic device. The system has been applied for the sensing of two different analyte types: biologically relevant phosphate anions and aromatic carboxylic acids, which are important for anthrax detection. A Eu(III)-EDTA complex was bound to ?-cyclodextrin monolayers via orthogonal supramolecular host-guest interactions. The self-assembly of the Eu(III)-EDTA conjugate and naphthalene ?-diketone as an antenna resulted in the formation of a highly luminescent lanthanide complex on the microchannel surface. Detection of different phosphate anions and aromatic carboxylic acids was demonstrated by monitoring the decrease in red emission following displacement of the antenna by the analyte. Among these analytes, adenosine triphosphate (ATP) andInt. J. Mol. Sci. 2011, 12 7336 pyrophosphate, as well as dipicolinic acid (DPA) which is a biomarker for anthrax, showed a strong response. Parallel fabrication of five sensing SAMs in a single multichannel chip

Bilge Eker; Mahmut Deniz Yilmaz; Stefan Schlautmann; Johannes G. E. Gardeniers; Jurriaan Huskens

2011-01-01

378

Radiolabeled Apoptosis Imaging Agents for Early Detection of Response to Therapy  

PubMed Central

Since apoptosis plays an important role in maintaining homeostasis and is associated with responses to therapy, molecular imaging of apoptotic cells could be useful for early detection of therapeutic effects, particularly in oncology. Radiolabeled annexin V compounds are the hallmark in apoptosis imaging in vivo. These compounds are reviewed from the genesis of apoptosis (cell death) imaging agents up to recent years. They have some disadvantages, including slow clearance and immunogenicity, because they are protein-based imaging agents. For this reason, several studies have been conducted in recent years to develop low molecule apoptosis imaging agents. In this review, radiolabeled phosphatidylserine targeted peptides, radiolabeled bis(zinc(II)-dipicolylamine) complex, radiolabeled 5-fluoropentyl-2-methyl-malonic acid (ML-10), caspase-3 activity imaging agents, radiolabeled duramycin, and radiolabeled phosphonium cation are reviewed as promising low-molecular-weight apoptosis imaging agents. PMID:25383382

2014-01-01

379

Protein toxins: intracellular trafficking for targeted therapy  

Microsoft Academic Search

The immunotoxin approach is based on the use of tumor-targeting ligands or antibodies that are linked to the catalytic (toxic) moieties of bacterial or plant protein toxins. In this review, we first discuss the current state of clinical development of immunotoxin approaches describing the results obtained with the two toxins most frequently used: diphtheria and Pseudomonas toxin-derived proteins. In the

L Johannes; D Decaudin

2005-01-01

380

Characterisation of the immune response to the UK human anthrax vaccine  

Microsoft Academic Search

The UK human anthrax vaccine consists of the alum-precipitated culture supernatant of Bacillus anthracis Sterne. In addition to protective antigen (PA), the key immunogen, the vaccine also contains a number of other bacteria- and media-derived proteins. These proteins may contribute to the transient side effects experienced by some individuals and could influence the development of the PA-specific immune response. Bacterial

Leslie Baillie; Richard Hebdon; Helen Flick-Smith; Diane Williamson

2003-01-01

381

Modeling low-dose mortality and disease incubation period of inhalational anthrax in the rabbit.  

PubMed

There is a need to advance our ability to conduct credible human risk assessments for inhalational anthrax associated with exposure to a low number of bacteria. Combining animal data with computational models of disease will be central in the low-dose and cross-species extrapolations required in achieving this goal. The objective of the current work was to apply and advance the competing risks (CR) computational model of inhalational anthrax where data was collected from NZW rabbits exposed to aerosols of Ames strain Bacillus anthracis. An initial aim was to parameterize the CR model using high-dose rabbit data and then conduct a low-dose extrapolation. The CR low-dose attack rate was then compared against known low-dose rabbit data as well as the low-dose curve obtained when the entire rabbit dose-response data set was fitted to an exponential dose-response (EDR) model. The CR model predictions demonstrated excellent agreement with actual low-dose rabbit data. We next used a modified CR model (MCR) to examine disease incubation period (the time to reach a fever >40 °C). The MCR model predicted a germination period of 14.5h following exposure to a low spore dose, which was confirmed by monitoring spore germination in the rabbit lung using PCR, and predicted a low-dose disease incubation period in the rabbit between 14.7 and 16.8 days. Overall, the CR and MCR model appeared to describe rabbit inhalational anthrax well. These results are discussed in the context of conducting laboratory studies in other relevant animal models, combining the CR/MCR model with other computation models of inhalational anthrax, and using the resulting information towards extrapolating a low-dose response prediction for man. PMID:23567649

Gutting, Bradford W; Marchette, David; Sherwood, Robert; Andrews, George A; Director-Myska, Alison; Channel, Stephen R; Wolfe, Daniel; Berger, Alan E; Mackie, Ryan S; Watson, Brent J; Rukhin, Andrey

2013-07-21

382

Delayed treatment with doxycycline has limited effect on anthrax infection in BLK57\\/B6 mice  

Microsoft Academic Search

Blk57\\/B6 mice were infected with LD90 dose of Sterne strain anthrax spores subcutaneously and then treated with doxycycline. Doxycycline at a dose of 1.5mg\\/kg, by intra-peritoneal injection, protected mice from death when given at the same time as spores. When doxycycline administration was delayed 4h survival is 90%. Delay of 24h increased survival time but had no impact on eventual

John Kalns; Julie Morris; Jeffrey Eggers; Johnathan Kiel

2002-01-01

383

Uncertain Science and Certain Deadlines: CDC Responses to the Media During the Anthrax Attacks of 2001  

Microsoft Academic Search

This paper presents a study in which communication personnel for the U.S. Centers for Disease Control and Prevention (CDC) provided first-hand accounts of the experience of responding to media inquiries during the 2001 anthrax attacks. In-depth interviews were conducted with 19 communication professionals who worked either at the CDC headquarters in Atlanta or at field locations in the U.S. where

SUSAN J. ROBINSON; WENDY C. NEWSTETTER

2003-01-01

384

Protocol for Real-Time PCR Identification of Anthrax Spores from Nasal Swabs after Broth Enrichment  

Microsoft Academic Search

A mass-screening protocol for the diagnosis of anthrax from nasal swabs based on an enrichment step in liquid medium was devised. Incubation for growth was performed in autoclavable vials and racks which allow real-time PCR analysis of sterilized cultures. A dual-color PCR was set up with primers and probes for the chromosomal marker rpoB and the plasmid marker lef. Specific

Marco R. Oggioni; Francesca Meacci; Alessandra Carattoli; Alessandra Ciervo; Germano Orru; Antonio Cassone; Gianni Pozzi; Universitadi Siena

2002-01-01

385

Anthrax outbreak in a Swedish beef cattle herd--1st case in 27 years: Case report.  

PubMed

After 27 years with no detected cases, an outbreak of anthrax occurred in a beef cattle herd in the south of Sweden. The outbreak was unusual as it occurred in winter, in animals not exposed to meat-and-bone meal, in a non-endemic country. The affected herd consisted of 90 animals, including calves and young stock. The animals were kept in a barn on deep straw bedding and fed only roughage. Seven animals died during 10 days, with no typical previous clinical signs except fever. The carcasses were reportedly normal in appearance, particularly as regards rigor mortis, bleeding and coagulation of the blood. Subsequently, three more animals died and anthrax was suspected at necropsy and confirmed by culture and PCR on blood samples. The isolated strain was susceptible to tetracycline, ciprofloxacin and ampicillin. Subtyping by MLVA showed the strain to cluster with isolates in the A lineage of Bacillus anthracis. Environmental samples from the holding were all negative except for two soil samples taken from a spot where infected carcasses had been kept until they were picked up for transport. The most likely source of the infection was concluded to be contaminated roughage, although this could not be substantiated by laboratory analysis. The suspected feed was mixed with soil and dust and originated from fields where flooding occurred the previous year, followed by a dry summer with a very low water level in the river allowing for the harvesting on soil usually not exposed. In the early 1900s, animal carcasses are said to have been dumped in this river during anthrax outbreaks and it is most likely that some anthrax spores could remain in the area. The case indicates that untypical cases in non-endemic areas may be missed to a larger extent than previously thought. Field tests allowing a preliminary risk assessment of animal carcasses would be helpful for increased sensitivity of detection and prevention of further exposure to the causative agent. PMID:20122147

Lewerin, Susanna Sternberg; Elvander, Marianne; Westermark, Therese; Hartzell, Lisbeth Nisu; Norström, Agneta Karlsson; Ehrs, Sara; Knutsson, Rickard; Englund, Stina; Andersson, Ann-Christin; Granberg, Malin; Bäckman, Stina; Wikström, Per; Sandstedt, Karin

2010-01-01

386

Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event Symposium  

SciTech Connect

On March 19, 2008, policy makers, emergency managers, and medical and Public Health officials convened in Seattle, Washington, for a workshop on Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event. The day-long symposium was aimed at generating a dialogue about restoration and recovery through a discussion of the associated challenges that impact entire communities, including people, infrastructure, and critical systems.

Lesperance, Ann M.

2008-06-30

387

Application of [18F]FDG in radiolabeling reactions using microfluidic technology.  

PubMed

Radiolabeling of peptides with the short-lived positron emitter fluorine-18 is usually a challenging endeavour. Conventional radiolabeling reactions mostly require fairly large amounts of peptides as labeling precursors, and extensive synthesis times. Intrinsic advantages of microfluidic technology permit to overcome these hurdles. Herein, we describe how microfluidic technology combined with [(18)F]FDG as readily available PET radiotracer allows for fast and high yielding radiolabeling reactions of peptides with fluorine-18. PMID:24056916

Bouvet, Vincent R; Wuest, Frank

2013-11-21

388

Identification of a Surrogate Marker for Infection in the African Green Monkey Model of Inhalation Anthrax?  

PubMed Central

In 2001, a bioterrorism attack involving Bacillus anthracis spore-laced letters resulted in 22 cases of inhalation anthrax, with five fatalities. This incident identified gaps in our health care system and precipitated a renewed interest in identifying both therapeutics and rapid diagnostic assays. To address those gaps, well-characterized animal models that resemble the human disease are needed. In addition, a rapid assay for a reliable diagnostic marker is key to the success of these efforts. In this study, we exposed African green monkeys to B. anthracis spores; examined clinical signs and physiological parameters, including fever, heart rate, complete blood count, and bacteremia; and evaluated the PCR assay and electrochemiluminescence (ECL) immunoassay for the biomarkers protective antigen and capsule. The results demonstrated that although there were neither objective clinical nor physiological signs that consistently identified either infection or the onset of clinical anthrax disease, the African green monkey is a suitable animal model exhibiting a disease course similar to that observed in the rhesus model and humans. We also demonstrated that detection of the biomarkers protective antigen and capsule correlated with bacterial loads in the blood of these nonhuman primates. The ECL immunoassay described here is simple and sensitive enough to provide results in one to two hours, making this assay a viable option for use in the diagnosis of anthrax, leading to timely initiation of treatment, which is a key component of B. anthracis therapeutic development. PMID:18852240

Rossi, Cynthia A.; Ulrich, Melanie; Norris, Sarah; Reed, Douglas S.; Pitt, Louise M.; Leffel, Elizabeth K.

2008-01-01

389

Interactions of High-Affinity Cationic Blockers with the Translocation Pores of B. anthracis, C. botulinum, and C. perfringens Binary Toxins  

PubMed Central

Cationic ?-cyclodextrin derivatives were recently introduced as highly effective, potentially universal blockers of three binary bacterial toxins: anthrax toxin of Bacillus anthracis, C2 toxin of Clostridium botulinum, and iota toxin of Clostridium perfringens. The binary toxins are made of two separate components: the enzymatic A component, which acts on certain intracellular targets, and the binding/translocation B component, which forms oligomeric channels in the target cell membrane. Here we studied the voltage and salt dependence of the rate constants of binding and dissociation reactions of two structurally different ?-cyclodextrins (AmPr?CD and AMBnT?CD) in the PA63, C2IIa, and Ib channels (B components of anthrax, C2, and iota toxins, respectively). With all three channels, the blocker carrying extra hydrophobic aromatic groups on the thio-alkyl linkers of positively charged amino groups, AMBnT?CD, demonstrated significantly stronger binding compared with AmPr?CD. This effect is seen as an increased residence time of the blocker in the channels, whereas the time between blockages characterizing the binding reaction on-rate stays practically unchanged. Surprisingly, the voltage sensitivity, expressed as a slope of the logarithm of the blocker residence time as a function of voltage, turned out to be practically the same for all six cases studied, suggesting structural similarities among the three channels. Also, the more-effective AMBnT?CD blocker shows weaker salt dependence of the binding and dissociation rate constants compared with AmPr?CD. By estimating the relative contributions of the applied transmembrane field, long-range Coulomb, and salt-concentration-independent, short-range forces, we found that the latter represent the leading interaction, which accounts for the high efficiency of blockage. In a search for the putative groups in the channel lumen that are responsible for the short-range forces, we performed measurements with the F427A mutant of PA63, which lacks the functionally important phenylalanine clamp. We found that the on-rates of the blockage were virtually conserved, but the residence times and, correspondingly, the binding constants dropped by more than an order of magnitude, which also reduced the difference between the efficiencies of the two blockers. PMID:22995493

Bezrukov, Sergey M.; Liu, Xian; Karginov, Vladimir A.; Wein, Alexander N.; Leppla, Stephen H.; Popoff, Michel R.; Barth, Holger; Nestorovich, Ekaterina M.

2012-01-01

390

Shiga toxins induce autophagy leading to differential signaling pathways in toxin-sensitive and toxin-resistant human cells  

PubMed Central

Summary The bacterial virulence factors Shiga toxins (Stxs) are expressed by Shigella dysenteriae serotype 1 and certain Escherichia coli strains. Stxs are protein synthesis inhibitors and induce apoptosis in many cell types. Stxs induce apoptosis via prolonged ER stress signaling to activate both extrinsic and intrinsic pathways in human myeloid cells. Studies have shown that autophagy, a lysosome-dependent catabolic process, may be associated with activation of pro-survival or death processes. It is currently unknown if autophagy contributes to apoptosis or protects cells from Stxs. To study cellular responses to Stxs, we intoxicated toxin-sensitive cells (THP-1 and HK-2 cells), and toxin-resistant cells (primary human monocyte-derived macrophages) and examined toxin intracellular trafficking and autophagosome formation. Stxs translocated to different cell compartments in toxin-resistant versus toxin-sensitive cells. Confocal microscopy revealed autophagosome formation in both toxin-resistant and toxin-sensitive cells. Proteolytic cleavage of Atg5 and Beclin-1 play pivotal roles in switching non-cytotoxic autophagy to cell death signaling. We detected cleaved forms of Atg5 and Beclin-1 in Stx-treated toxin-sensitive cells, while cleaved caspases, calpains, Atg5 and Beclin-1 were not detected in toxin-resistant primary human monocytes and macrophages. These findings suggest that toxin sensitivity correlates with caspase and calpain activation, leading to Atg5 and Beclin-1 cleavage. PMID:21722286

Lee, Moo-Seung; Cherla, Rama P.; Jenson, Matthew H.; Leyva-Illades, Dinorah; Martinez-Moczygemba, Margarita; Tesh, Vernon L.

2011-01-01

391

MCEARD - CYANOBACTERIA AND THEIR TOXINS  

EPA Science Inventory

Harmful algal blooms (HAB) of cyanobacteria, also known as blue-green algae, have recently become more spatially and temporally prevalent in the US and worldwide. Waterborne cyanobacteria and their highly potent toxins are a significant hazard for human health and the ecosystem....

392

Risk Assessment of Shellfish Toxins  

PubMed Central

Complex secondary metabolites, some of which are highly toxic to mammals, are produced by many marine organisms. Some of these organisms are important food sources for marine animals and, when ingested, the toxins that they produce may be absorbed and stored in the tissues of the predators, which then become toxic to animals higher up the food chain. This is a particular problem with shellfish, and many cases of poisoning are reported in shellfish consumers each year. At present, there is no practicable means of preventing uptake of the toxins by shellfish or of removing them after harvesting. Assessment of the risk posed by such toxins is therefore required in order to determine levels that are unlikely to cause adverse effects in humans and to permit the establishment of regulatory limits in shellfish for human consumption. In the present review, the basic principles of risk assessment are described, and the progress made toward robust risk assessment of seafood toxins is discussed. While good progress has been made, it is clear that further toxicological studies are required before this goal is fully achieved. PMID:24226039

Munday, Rex; Reeve, John

2013-01-01

393

Inactivation of allergens and toxins.  

PubMed

Plants are replete with thousands of proteins and small molecules, many of which are species-specific, poisonous or dangerous. Over time humans have learned to avoid dangerous plants or inactivate many toxic components in food plants, but there is still room for ameliorating food crops (and plants in general) in terms of their allergens and toxins content, especially in their edible parts. Inactivation at the genetic rather than physical or chemical level has many advantages and classical genetic approaches have resulted in significant reduction of toxin content. The capacity, offered by genetic engineering, of turning off (inactivating) specific genes has opened up the possibility of altering the plant content in a far more precise manner than previously available. Different levels of intervention (genes coding for toxins/allergens or for enzymes, transporters or regulators involved in their metabolism) are possible and there are several tools for inactivating genes, both direct (using chemical and physical mutagens, insertion of transposons and other genetic elements) and indirect (antisense RNA, RNA interference, microRNA, eventually leading to gene silencing). Each level/strategy has specific advantages and disadvantages (speed, costs, selectivity, stability, reversibility, frequency of desired genotype and regulatory regime). Paradigmatic examples from classical and transgenic approaches are discussed to emphasize the need to revise the present regulatory process. Reducing the content of natural toxins is a trade-off process: the lesser the content of natural toxins, the higher the susceptibility of a plant to pests and therefore the stronger the need to protect plants. As a consequence, more specific pesticides like Bt are needed to substitute for general pesticides. PMID:20601271

Morandini, Piero

2010-11-30

394

Advax-adjuvanted recombinant protective antigen provides protection against inhalational anthrax that is further enhanced by addition of murabutide adjuvant.  

PubMed

Subunit vaccines against anthrax based on recombinant protective antigen (PA) potentially offer more consistent and less reactogenic anthrax vaccines but require adjuvants to achieve optimal immunogenicity. This study sought to determine in a murine model of pulmonary anthrax infection whether the polysaccharide adjuvant Advax or the innate immune adjuvant murabutide alone or together could enhance PA immunogenicity by comparison to an alum adjuvant. A single immunization with PA plus Advax adjuvant afforded significantly greater protection against aerosolized Bacillus anthracis Sterne strain 7702 than three immunizations with PA alone. Murabutide had a weaker adjuvant effect than Advax when used alone, but when murabutide was formulated together with Advax, an additive effect on immunogenicity and protection was observed, with complete protection after just two doses. The combined adjuvant formulation stimulated a robust, long-lasting B-cell memory response that protected mice against an aerosol challenge 18 months postimmunization with acceleration of the kinetics of the anamnestic IgG response to B. anthracis as reflected by ?4-fold-higher anti-PA IgG titers by day 2 postchallenge versus mice that received PA with Alhydrogel. In addition, the combination of Advax plus murabutide induced approximately 3-fold-less inflammation than Alhydrogel as measured by in vivo imaging of cathepsin cleavage resulting from injection of ProSense 750. Thus, the combination of Advax and murabutide provided enhanced protection against inhalational anthrax with reduced localized inflammation, making this a promising next-generation anthrax vaccine adjuvanting strategy. PMID:24554695

Feinen, Brandon; Petrovsky, Nikolai; Verma, Anita; Merkel, Tod J

2014-04-01

395

Dual-mode imaging with radiolabeled gold nanorods  

PubMed Central

Many nanoparticle contrast agents have difficulties with deep tissue and near-bone imaging due to limited penetration of visible photons in the body and mineralized tissues. We are looking into the possibility of mediating this problem while retaining the capabilities of the high spatial resolution associated with optical imaging. As such, the potential combination of emerging photoacoustic imaging and nuclear imaging in monitoring of antirheumatic drug delivery by using a newly developed dual-modality contrast agent is investigated. The contrast agent is composed of gold nanorods (GNRs) conjugated to the tumor necrosis factor (TNF-?) antibody and is subsequently radiolabeled by 125I. ELISA experiments designed to test TNF-? binding are performed to prove the specificity and biological activity of the radiolabeled conjugated contrast agent. Photoacoustic and nuclear imaging are performed to visualize the distribution of GNRs in articular tissues of the rat tail joints in situ. Findings from the two imaging modalities correspond well with each other in all experiments. Our system can image GNRs down to a concentration of 10 pM in biological tissues and with a radioactive label of 5 ?Ci. This study demonstrates the potential of combining photoacoustic and nuclear imaging modalities through one targeted contrast agent for noninvasive monitoring of drug delivery as well as deep and mineralized tissue imaging. PMID:21639567

Agarwal, Ashish; Shao, Xia; Rajian, Justin R.; Zhang, Huanan; Chamberland, David L.; Kotov, Nicholas A.; Wang, Xueding

2011-01-01

396

Biokinetics and dosimetry of several radiolabelled peptides in cancer cells  

NASA Astrophysics Data System (ADS)

Radiolabelled peptides have been used as target-specific radiopharmaceuticals. The goal of this research was the in vitro assessment of the uptake, internalization, externalization, and efflux of five radiolabelled peptides in cancer cells to estimate radiation-absorbed doses from experimental biokinetic data. 177Lu-DOTA-octreotate, 188Re-lanreotide, and 99mTc-HYNIC-octreotide were studied in the AR42J cell line. The PC3 and NCIH69 cells were used for 99mTc-HYNIC-bombesin and 177Lu-DOTA-minigastrin, respectively. The cumulated activities in the membrane and cytoplasm were calculated by integration of the experimental time-activity curves and used for dosimetry calculations according to the Medical Internal Radiation Dose (MIRD) cellular methodology. The mean absorbed dose to the cell nucleus were 0.69±0.09, 0.11±0.08, 0.55±0.09, 3.45±0.48, and 3.30±0.65 Gy/Bq for 99mTc-HYNIC-bombesin, 99mTc-HYNIC-octreotide, 177Lu-DOTA-minigastrin, 177Lu-DOTA-octreotate, and 188Re-lanreotide, respectively. If radiopharmaceutical cell kinetics were not used and only uptake data were considered, the calculated doses would be overestimated up to 25 times.

Rodríguez-Cortés, J.; Ferro-Flores, G.; de Murphy, C. Arteaga; Pedraza-López, M.; Ramírez-Iglesias, M. A. T.

397

Radiolabeling and in vivo distribution of nanobacteria in rabbits  

NASA Astrophysics Data System (ADS)

Nanobacteria are minute bacteria recently isolated from mammalian blood. They encapsulate themselves with apatite mineral. Cultured nanobacteria were radiolabeled with (superscript 99m)Tc, using a method which has been previously used for labeling red blood cells with (superscript 99m)Tc, and in vivo distribution of nanobacteria was followed with Single Photon Emission Computed Tomography (SPECT) imaging. The labeling yield was over 30%. Two rabbits were studied using dynamic planar imaging performed in the AP-position immediately after injection. Serial SPECT scans were acquired up to 24 h and one planar image was taken at 45 h. A control study was performed administering a similar dose of [(superscript 99m)Tc] labeled albumin nanocolloids. Regional nanobacteria-to- nanocolloid ratios were calculated along with time and tissues (45 h) were analyzed for radioactivity and for nanobacteria. The main finding was that radiolabeled nanobacteria remained intact and showed a tissue specific distribution with a high accumulation in the kidneys and also in urine. Spleen, stomach, heart and intestine also showed increased uptake. Excretion into urine started 10 - 15 min after injection. These were live nanobacteria in the urine, which had better capabilities to penetrate into cells in vitro. The nanobacteria accessed the urine via tubular cells since nanobacteria were found in their cytoplasm and tubular surfaces. The results suggest that nanobacteria utilize endocytic transport of tubular cells and may be involved in the pathogenesis of mineral formation in mammalian kidney stones.

Akerman, Kari K.; Kuikka, Jyrki T.; Ciftcioglu, Neva; Parkkinen, Jyrki; Bergstroem, Kim A.; Kuronen, Ilpo; Kajander, E. Olavi

1997-07-01

398

Quantitative autoradiographic mapping of focal herpes simplex virus encephalitis using a radiolabeled antiviral drug  

SciTech Connect

A method of mapping herpes simplex viral infection comprising administering a radiolabeled antiviral active 5-substituted 1-(2'-deoxy-2'-substituted-D-arabinofuranosyl) pyrimidine nucleoside to the infected subject, and scanning the area in which the infection is to be mapped for the radiolabel.

Price, R.

1984-12-18

399

The toxin and antidote puzzle  

PubMed Central

Insects carry out essential ecological functions, such as pollination, but also cause extensive damage to agricultural crops and transmit human diseases such as malaria and dengue fever. Advances in insect transgenesis are making it increasingly feasible to engineer genes conferring desirable phenotypes, and gene drive systems are required to spread these genes into wild populations. Medea provides one solution, being able to spread into a population from very low initial frequencies through the action of a maternally-expressed toxin linked to a zygotically-expressed antidote. Several other toxin-antidote combinations are imaginable that distort the offspring ratio in favor of a desired transgene, or drive the population towards an all-male crash. We explore two such systems—Semele, which is capable of spreading a desired transgene into an isolated population in a confined manner; and Merea, which is capable of inducing a local population crash when located on the Z chromosome of a Lepidopteron pest. PMID:21876382

2011-01-01

400

An update on uremic toxins.  

PubMed

In the last decade, uremic toxicity as a potential cause for the excess of cardiovascular disease and mortality observed in chronic kidney disease gained more and more interest. This review focuses on uremic toxins with known cardiovascular effects and their removal. For protein-bound solutes, for example, indoxylsulfate and the conjugates of p-cresol, and for small water-soluble solutes, for example, guanidines, such as ADMA and SDMA, there is a growing evidence for a role in cardiovascular toxicity in vitro (e.g., affecting leukocyte, endothelial, vascular smooth muscle cell function) and/or in vivo. Several middle molecules (e.g., beta-2-microglobulin, interleukin-6, TNF-alpha and FGF-23) were shown to be predictors for cardiovascular disease and/or mortality. Most of these solutes, however, are difficult to remove during dialysis, which is traditionally assessed by studying the removal of urea, which can be considered as a relatively inert uremic retention solute. However, even the effective removal of other small water-soluble toxins than urea can be hampered by their larger distribution volumes. Middle molecules (beta-2-microglobulin as prototype, but not necessarily representative for others) are cleared more efficiently when the pore size of the dialyzer membrane increases, convection is applied and dialysis time is prolonged. Only adding convection to diffusion improves the removal of protein-bound toxins. Therefore, alternative removal strategies, such as intestinal adsorption, drugs interfering with toxic biochemical pathways or decreasing toxin concentration, and extracorporeal plasma adsorption, as well as kinetic behavior during dialysis need further investigation. Even more importantly, randomized clinical studies are required to demonstrate a survival advantage through these strategies. PMID:22893494

Neirynck, N; Vanholder, R; Schepers, E; Eloot, S; Pletinck, A; Glorieux, G

2013-02-01

401

Bt Toxin Modification for Enhanced Efficacy  

PubMed Central

Insect-specific toxins derived from Bacillus thuringiensis (Bt) provide a valuable resource for pest suppression. Here we review the different strategies that have been employed to enhance toxicity against specific target species including those that have evolved resistance to Bt, or to modify the host range of Bt crystal (Cry) and cytolytic (Cyt) toxins. These strategies include toxin truncation, modification of protease cleavage sites, domain swapping, site-directed mutagenesis, peptide addition, and phage display screens for mutated toxins with enhanced activity. Toxin optimization provides a useful approach to extend the utility of these proteins for suppression of pests that exhibit low susceptibility to native Bt toxins, and to overcome field resistance. PMID:25340556

Deist, Benjamin R.; Rausch, Michael A.; Fernandez-Luna, Maria Teresa; Adang, Michael J.; Bonning, Bryony C.

2014-01-01

402

Bt toxin modification for enhanced efficacy.  

PubMed

Insect-specific toxins derived from Bacillus thuringiensis (Bt) provide a valuable resource for pest suppression. Here we review the different strategies that have been employed to enhance toxicity against specific target species including those that have evolved resistance to Bt, or to modify the host range of Bt crystal (Cry) and cytolytic (Cyt) toxins. These strategies include toxin truncation, modification of protease cleavage sites, domain swapping, site-directed mutagenesis, peptide addition, and phage display screens for mutated toxins with enhanced activity. Toxin optimization provides a useful approach to extend the utility of these proteins for suppression of pests that exhibit low susceptibility to native Bt toxins, and to overcome field resistance. PMID:25340556

Deist, Benjamin R; Rausch, Michael A; Fernandez-Luna, Maria Teresa; Adang, Michael J; Bonning, Bryony C

2014-10-01

403

Radiolabeling of Nanoparticles and Polymers for PET Imaging  

PubMed Central

Nanomedicine has become an emerging field in imaging and therapy of malignancies. Nanodimensional drug delivery systems have already been used in the clinic, as carriers for sensitive chemotherapeutics or highly toxic substances. In addition, those nanodimensional structures are further able to carry and deliver radionuclides. In the development process, non-invasive imaging by means of positron emission tomography (PET) represents an ideal tool for investigations of pharmacological profiles and to find the optimal nanodimensional architecture of the aimed-at drug delivery system. Furthermore, in a personalized therapy approach, molecular imaging modalities are essential for patient screening/selection and monitoring. Hence, labeling methods for potential drug delivery systems are an indispensable need to provide the radiolabeled analog. In this review, we describe and discuss various approaches and methods for the labeling of potential drug delivery systems using positron emitters. PMID:24699244

Stockhofe, Katharina; Postema, Johannes M.; Schieferstein, Hanno; Ross, Tobias L.

2014-01-01

404

Storage stability of paralytic shellfish poisoning toxins  

Microsoft Academic Search

Variations in C toxins (C1- 2), GTX (gonyautoxin) 1-4, STX (saxitoxin) and NEO (neosaxitoxin) in scallop digestive glands and a mixture of purified paralytic shellfish poisoning (PSP) toxins were studied during storage at ?35, 5 and 25°C and at different pH levels. Heated and unheated samples of homogenates and purified toxin mixtures were stored for 1 year and 4 months,

W. M Indrasena; T. A Gill

2000-01-01

405

Prokaryotic toxin–antitoxin stress response loci  

Microsoft Academic Search

Although toxin–antitoxin gene cassettes were first found in plasmids, recent database mining has shown that these loci are abundant in free-living prokaryotes, including many pathogenic bacteria. For example, Mycobacterium tuberculosis has 38 chromosomal toxin–antitoxin loci, including 3 relBE and 9 mazEF loci. RelE and MazF are toxins that cleave mRNA in response to nutritional stress. RelE cleaves mRNAs that are

Susanne K. Christensen; Anders Løbner-Olesen; Kenn Gerdes

2005-01-01

406

Germination and Amplification of Anthrax Spores by Soil-Dwelling Amoebas  

PubMed Central

While anthrax is typically associated with bioterrorism, in many parts of the world the anthrax bacillus (Bacillus anthracis) is endemic in soils, where it causes sporadic disease in livestock. These soils are typically rich in organic matter and calcium that promote survival of resilient B. anthracis spores. Outbreaks of anthrax tend to occur in warm weather following rains that are believed to concentrate spores in low-lying areas where runoff collects. It has been concluded that elevated spore concentrations are not the result of vegetative growth as B. anthracis competes poorly against indigenous bacteria. Here, we test an alternative hypothesis in which amoebas, common in moist soils and pools of standing water, serve as amplifiers of B. anthracis spores by enabling germination and intracellular multiplication. Under simulated environmental conditions, we show that B. anthracis germinates and multiplies within Acanthamoeba castellanii. The growth kinetics of a fully virulent B. anthracis Ames strain (containing both the pX01 and pX02 virulence plasmids) and vaccine strain Sterne (containing only pX01) inoculated as spores in coculture with A. castellanii showed a nearly 50-fold increase in spore numbers after 72 h. In contrast, the plasmidless strain 9131 showed little growth, demonstrating that plasmid pX01 is essential for growth within A. castellanii. Electron and time-lapse fluorescence microscopy revealed that spores germinate within amoebal phagosomes, vegetative bacilli undergo multiplication, and, following demise of the amoebas, bacilli sporulate in the extracellular milieu. This analysis supports our hypothesis that amoebas contribute to the persistence and amplification of B. anthracis in natural environments. PMID:22983962

Dey, Rafik; Hoffman, Paul S.

2012-01-01

407

Cross-resistance and mechanism of resistance to Cry1Ab toxin from Bacillus thuringiensis in a field-derived strain of European corn borer, Ostrinia nubilalis.  

PubMed

The cross-resistance spectrum and biochemical mechanism of resistance to the Bacillus thuringiensis Cry1Ab toxin was studied in a field-derived strain of Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) that was further selected in the laboratory for high levels (>1000-fold) of resistance to Cry1Ab. The resistant strain exhibited high levels of cross-resistance to Cry1Ac and Cry1Aa but only low levels of cross-resistance (<4-fold) to Cry1F. In addition, there was no significant difference between the levels of resistance to full-length and trypsin-activated Cry1Ab protein. No differences in activity of luminal gut proteases or altered proteolytic processing of the toxin were observed in the resistant strain. Significantly reduced binding of radiolabeled Cry1Aa was observed in the resistant strain whereas binding of Cry1Ab and Cry1Ac was practically the same in both resistant and susceptible strains. The interpretation of the overall data seems to suggest the involvement of an alteration in the binding of Cry1A toxins to a common receptor, which is more clearly revealed by the binding assays using radiolabeled Cry1Aa. PMID:21550350

Crespo, André L B; Rodrigo-Simón, Ana; Siqueira, Herbert A A; Pereira, Eliseu J G; Ferré, Juan; Siegfried, Blair D

2011-07-01

408

Toxin Detection by Surface Plasmon Resonance  

PubMed Central

Significant efforts have been invested in the past years for the development of analytical methods for fast toxin detection in food and water. Immunochemical methods like ELISA, spectroscopy and chromatography are the most used in toxin detection. Different methods have been linked, e.g. liquid chromatography and mass spectrometry (LC-MS), in order to detect as low concentrations as possible. Surface plasmon resonance (SPR) is one of the new biophysical methods which enables rapid toxin detection. Moreover, this method was already included in portable sensors for on-site determinations. In this paper we describe some of the most common methods for toxin detection, with an emphasis on SPR. PMID:22573957

Hodnik, Vesna; Anderluh, Gregor

2009-01-01

409

Genomic Copy Number Variants: Evidence for Association with Antibody Response to Anthrax Vaccine Adsorbed  

PubMed Central

Background Anthrax and its etiologic agent remain a biological threat. Anthrax vaccine is highly effective, but vaccine-induced IgG antibody responses vary widely following required doses of vaccinations. Such variation can be related to genetic factors, especially genomic copy number variants (CNVs) that are known to be enriched among genes with immunologic function. We have tested this hypothesis in two study populations from a clinical trial of anthrax vaccination. Methods We performed CNV-based genome-wide association analyses separately on 794 European Americans and 200 African-Americans. Antibodies to protective antigen were measured at week 8 (early response) and week 30 (peak response) using an enzyme-linked immunosorbent assay. We used DNA microarray data (Affymetrix 6.0) and two CNV detection algorithms, hidden markov model (PennCNV) and circular binary segmentation (GeneSpring) to determine CNVs in all individuals. Multivariable regression analyses were used to identify CNV-specific associations after adjusting for relevant non-genetic covariates. Results Within the 22 autosomal chromosomes, 2,943 non-overlapping CNV regions were detected by both algorithms. Genomic insertions containing HLA-DRB5, DRB1 and DQA1/DRA genes in the major histocompatibility complex (MHC) region (chromosome 6p21.3) were moderately associated with elevated early antibody response (??=?0.14, p?=?1.78×10?3) among European Americans, and the strongest association was observed between peak antibody response and a segmental insertion on chromosome 1, containing NBPF4, NBPF5, STXMP3, CLCC1, and GPSM2 genes (??=?1.66, p?=?6.06×10?5). For African-Americans, segmental deletions spanning PRR20, PCDH17 and PCH68 genes on chromosome 13 were associated with elevated early antibody production (??=?0.18, p?=?4.47×10?5). Population-specific findings aside, one genomic insertion on chromosome 17 (containing NSF, ARL17 and LRRC37A genes) was associated with elevated peak antibody response in both populations. Conclusion Multiple CNV regions, including the one consisting of MHC genes that is consistent with earlier research, can be important to humoral immune responses to anthrax vaccine adsorbed. PMID:23741398

Wineinger, Nathan E.; Cutter, Gary R.; Kimberly, Robert P.; Edberg, Jeffrey C.; Arnett, Donna K.; Kaslow, Richard A.; Tang, Jianming; Shrestha, Sadeep

2013-01-01

410

Poisoned food, poisoned uniforms, and anthrax: or, how guerillas die in war.  

PubMed

Many people believe that Rhodesia, struggling to maintain minority rule in Africa, used chemical and biological weapons against African guerilla armies in the liberation war. Clothes and food were routinely poisoned, and Rhodesian agents, perhaps in concert with global forces of reaction, caused the largest single outbreak of anthrax in modern times. Oral interviews with traditional healers and Rhodesians' confessional memoirs of the war suggest that deaths by poisoning or disease were not so straightforward, that guerillas and healers and doctors struggled to understand not only what caused death but also what kind of death a poisoned uniform or poisoned boot was. PMID:15484386

White, Luise

2004-01-01

411

Anthrax letters: personal exposure, building contamination, and effectiveness of immediate mitigation measures.  

PubMed

This report is the first detailed and quantitative study of potential mitigation procedures intended to deal with anthrax letters using a simulated anthrax letter release within an actual office building. Spore aerosols were created by opening letters containing 0.1 g of dry powdered Bacillus atrophaeus spores. Culturable aerosol samples were collected using slit-to-agar and filter-based samplers. Five test scenarios were designed to determine whether simple mitigation procedures or activities carried out by the person who opened the letter made a significant difference to aerosol concentrations in comparison to a control scenario where no activity took place. Surface contamination of the letter opener was measured at 10 body points for Scenarios 1 to 4. A sixth scenario, based on published Centers for Disease Control and Prevention anthrax letter response guidelines, used letters containing 1 g of spores. Results demonstrated that the spore aerosol spread throughout the building in less than 4.5 min. Potential mitigation techniques such as closing the office door or shutting off the ventilation system were not effective. Activities carried out by the letter opener including moving, walking to another location, and spraying water onto the contaminated desk with a hand sprayer all resulted in significantly higher aerosol concentrations in comparison to control. The potential total inhalational hazard for the letter opener during the five test scenarios ranged from 4.1 x 10(5) to 1.6 x 10(6) colony forming units (CFU) compared to 3.9 x 10(5) CFU for the control. Surface contamination of the letter opener (Scenarios 1 to 4) was highest on the right hip (4.8 x 10(4) to 1.0 x 10(5) CFU/cm(- 2)) and lowest on the right or left side of the head (2.2 x 10(2) to 3.7 x 10(3) CFU/cm(-2)). The statistically based methodology used in this study provided the means to objectively assess anthrax letter protocols to determine their effectiveness under realistic conditions. Potential mitigation procedures tested in this study did not reduce aerosol hazard or surface contamination. PMID:19916102

Kournikakis, Bill; Ho, Jim; Duncan, Scott

2010-02-01

412

Toxins 2011, 3, 1502-1517; doi:10.3390/toxins3121502 ISSN 2072-6651  

E-print Network

Toxins 2011, 3, 1502-1517; doi:10.3390/toxins3121502 toxins ISSN 2072-6651 www.mdpi.com/journal common cause of refusal of grain deliveries to the food industry due to non-compliance with health regulations. Hence, it is imperative to find new molecules with less impact on the environment. One

Boyer, Edmond

413

TOXINS IN BIOTECHNOLOGY / 1 Animal Toxins in the World of Modern  

E-print Network

TOXINS IN BIOTECHNOLOGY / 1 Animal Toxins in the World of Modern Biotechnology JEAN-MARC SABATIER1 Biotechnologies, Bâtiment Biopolis, 5, avenue du Grand Sablon, 38700 La Tronche, France. Tel.: +33-4-56520563; Fax: +33-4-56520637; E-mail address: michel.dewaard@ujf-grenoble.fr Running title: Toxins in Biotechnology

Paris-Sud XI, Université de

414

Ability of ELISA and a toxin neutralization assay to detect changes in immunogenicity of a recombinant Bacillus anthracis protective antigen vaccine upon storage.  

PubMed

We examined the capability of a mouse immunogenicity assay to detect improper storage of a recombinant protective antigen (rPA)-based anthrax vaccine formulated with an aluminum adjuvant, using ELISA and a toxin neutralization assay (TNA) to measure the antibody response to rPA. The vaccine was stored at 4 °C, room temperature (RT) or 37 °C for one, four and eight weeks and used for immunization, along with freshly prepared vaccine. Results showed that, contrary to ELISA, TNA is suitable to detect a loss of immunogenicity of the rPA vaccine following its exposure to RT for a period of eight weeks and to 37 °C for a period as short as 1 week. PMID:23137818

Domínguez-Castillo, Rocío I; Verma, Anita; Amador-Molina, Juan C; Sirota, Lev; Arciniega, Juan L

2013-03-01

415

Biologic response to environmental toxins  

SciTech Connect

Biological response to environmental toxins results from the sum of natural, environmental, avocational, inapparent, and occupational exposures. These external exposures result in acceptable or unacceptable levels of absorption or internal exposure based on anticipated biological effects. There is no level of exposure which is in and of itself synonymous with intoxication. Biological effects may be classified as physiologic or pathologic, adaptive or nonadaptive, respectively. In each instance, the response may be acceptable or unacceptable. Intoxication requires the demonstration of a significant impairment of health. One may have an unacceptable pathologic response and still not have intoxication. Professional judgment is required.

Lerner, S.

1983-12-01

416

Botulinum toxin for axillary hyperhidrosis.  

PubMed

Botulinum toxin is a safe and effective treatment option for axillary hyperhidrosis. Although its pathophysiology is not clear and somewhat controversial, the beneficial effect of neuromodulators in inhibiting localized sweating temporarily is well known. Before the procedure, correct identification of the affected area is mandatory to avoid wastage of drug and neglect of target areas, and to enhance efficacy, as the hyperhidrotic location may not match the hairy axillary region. Utilization of this medication, such as dilution and injection techniques, depends on medical experience and may have some variations, including methods to make the procedure as painless as possible. PMID:25152343

de Almeida, Ada Regina Trindade; Montagner, Suelen

2014-10-01

417

A simple method for the separation and quantitation of radiolabeled thyroid hormones in thyroxine clearance studies.  

PubMed

A method was developed to facilitate the separation and quantitation of radiolabeled thyroxine in plasma for thyroxine clearance studies. Following intravenous injection of radioactive thyroxine, the radiolabeled thyroid hormones were isolated from plasma protein and polar metabolites by solid phase extraction on a C18 sorbent bed. The individual thyroid hormones were then separated by ion-pair reversed phase chromatography and sequentially eluted through a UV detector and radiochromatographic detector. The radioactivity of individual radiolabeled thyroid hormones was corrected for recovery of carrier as determined from UV absorbance. The recoveries of thyroxine and 3,5,3'-triiodothyronine (T3) were 96% and 101%, respectively. PMID:2074718

Grossman, S J

1990-11-01

418

Direct radiolabeling of antibody against stage specific embryonic antigen for diagnostic imaging  

DOEpatents

Antibody against stage specific embryonic antigen-1 is radiolabeled by direct means with a radionuclide for use in detection of occult abscess and inflammation. Radiolabeling is accomplished by partial reduction of the disulfide bonds of the antibody using Sn(II), or using other reducing agents followed by the addition of Sn(II), removal of excess reducing agent and reduction by-products, and addition of a specified amount of radionuclide reducing agent, such as stannous tartrate. The resulting product may be store frozen or lyophilized, with radiolabeling accomplished by the addition of the radionuclide.

Rhodes, Buck A. (Albuquerque, NM)

1994-01-01

419

The role of toxin A and toxin B in Clostridium difficile-associated disease  

PubMed Central

Recently, we constructed and characterized isogenic tcdA and tcdB mutants of a virulent Clostridium difficile strain and used a hamster model of disease to demonstrate that toxin B, not toxin A, is essential for virulence of this emerging pathogen. Earlier studies had shown that purified toxin A alone was able to induce C. difficile disease pathology and that purified toxin B was not effective unless it was co-administered with toxin A, suggesting that the toxins act synergistically. In this addendum we discuss this paradigm-shifting conclusion in the context of current strain epidemiology, particularly with respect to naturally occurring toxin A-negative, toxin B-positive isolates and the NAP1/027 epidemic isolates. The role of toxin receptors and how variant toxins might exert their effects is also discussed in relation to the published data. We conclude that it is critical to use the natural infection process to dissect the role of toxins in disease, and that future studies are contingent on such work. The impact and importance of animal models of C. difficile virulence are therefore considered within this frame of reference. PMID:20664812

Carter, Glen P; Rood, Julian I

2010-01-01

420

DNA probes for Shiga-like toxins I and II and for toxin-converting bacteriophages.  

PubMed Central

A set of DNA probes has been developed to study the genes for Shiga-like toxins (SLT) and the bacteriophage from which these toxin genes were isolated. Under stringent conditions of hybridization (80 to 90% homology), these probes detect strains containing (i) SLT I-related genes, (ii) SLT II-related genes, (iii) phage sequences from the SLT I-converting phage H19A/933J, and (iv) phage sequences from the SLT II-converting phage 933W. Strain characterization by hybridization with the toxin gene probes was as accurate as methods that used toxin-specific antibody to determine toxin synthesis. Screening of different gram-negative bacteria with the toxin probes revealed that only two species carry sequences related to the SLT genes, Escherichia coli and Shigella dysenteriae 1. These results indicated that the lower levels of toxin activity observed in shigellae other than S. dysenteriae 1 are due to a gene(s) that is genetically distinct from that which encodes Shiga toxin. Analysis of enterotoxigenic, enteroinvasive, enteropathogenic, and enterohemorrhagic E. coli indicated that SLT genes are found primarily in the enterohemorrhagic E. coli strain group. Use of both the toxin and the phage probes has identified a variety of genotypic combinations of phage and toxin sequences which differ from those observed for the original toxin-converting phage isolates, for E. coli O157:H7 strain 933, and for E. coli O26:H11 strain H19. Images PMID:2842369

Newland, J W; Neill, R J

1988-01-01

421

9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.  

...the lot. (c) Apparently healthy livestock (other than hogs...detected, and any apparently healthy livestock which have been treated...biologicals which do not contain living anthrax organisms, may be...if desired, all apparently healthy livestock of the lot...

2014-01-01

422

9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.  

Code of Federal Regulations, 2011 CFR

...the lot. (c) Apparently healthy livestock (other than hogs...detected, and any apparently healthy livestock which have been treated...biologicals which do not contain living anthrax organisms, may be...if desired, all apparently healthy livestock of the lot...

2011-01-01

423

9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.  

Code of Federal Regulations, 2013 CFR

...the lot. (c) Apparently healthy livestock (other than hogs...detected, and any apparently healthy livestock which have been treated...biologicals which do not contain living anthrax organisms, may be...if desired, all apparently healthy livestock of the lot...

2013-01-01

424

9 CFR 309.7 - Livestock affected with anthrax; cleaning and disinfection of infected livestock pens and driveways.  

Code of Federal Regulations, 2012 CFR

...the lot. (c) Apparently healthy livestock (other than hogs...detected, and any apparently healthy livestock which have been treated...biologicals which do not contain living anthrax organisms, may be...if desired, all apparently healthy livestock of the lot...

2012-01-01

425

Investigation, control and epizootiology of anthrax in a geographically isolated, free-roaming bison population in northern Canada.  

PubMed Central

In July 1993 anthrax caused significant mortality in an isolated, free-ranging population of bison (Bos bison athabascae) west of Great Slave Lake in the Northwest Territories. There was no previous record of anthrax in this area. An emergency response was undertaken to reduce the scale of environmental contamination and dissemination of anthrax spores and hence to reduce the likelihood of future outbreaks. One-hundred-and-seventy-two bison, 3 moose (Alces alces), and 3 black bear (Ursus americanus) carcasses were found. Visual detection of carcasses was enhanced with the use of an airborne, remote infrared sensing camera mounted externally on a helicopter. Fifty-five percent of the carcasses were located in forested or shrub-covered sites where detection would not have been likely without the thermal imaging equipment. Carcasses were disposed of by incineration and the sites were decontaminated with formaldehyde. Application of formaldehyde to carcasses prevented scavenging. The outbreak occurred after a prolonged period of drying between April and mid-July 1993 which followed several successive years of flooding of bison habitat. The "spore concentration hypothesis" provides the most conservative explanation for the occurrence of anthrax under the observed conditions. Images Fig. 1. Fig. 2. PMID:8548686

Gates, C C; Elkin, B T; Dragon, D C

1995-01-01

426

Structures of Bioterrorism Preparedness in the UK and the US: Responses to 9\\/11 and the Anthrax Attacks  

Microsoft Academic Search

This article describes UK and US responses to 9\\/11 and the subsequent anthrax attacks, referring to 'biodefence' and the civilian structures of disaster preparedness. Following a review of initia- tives undertaken in each country the article details principal differences between the two systems, the federal nature of the US response and the more localised arrangements preferred in the UK. Finally,

Dan Jones

2005-01-01

427

Investigation, control and epizootiology of anthrax in a geographically isolated, free-roaming bison population in northern Canada.  

PubMed

In July 1993 anthrax caused significant mortality in an isolated, free-ranging population of bison (Bos bison athabascae) west of Great Slave Lake in the Northwest Territories. There was no previous record of anthrax in this area. An emergency response was undertaken to reduce the scale of environmental contamination and dissemination of anthrax spores and hence to reduce the likelihood of future outbreaks. One-hundred-and-seventy-two bison, 3 moose (Alces alces), and 3 black bear (Ursus americanus) carcasses were found. Visual detection of carcasses was enhanced with the use of an airborne, remote infrared sensing camera mounted externally on a helicopter. Fifty-five percent of the carcasses were located in forested or shrub-covered sites where detection would not have been likely without the thermal imaging equipment. Carcasses were disposed of by incineration and the sites were decontaminated with formaldehyde. Application of formaldehyde to carcasses prevented scavenging. The outbreak occurred after a prolonged period of drying between April and mid-July 1993 which followed several successive years of flooding of bison habitat. The "spore concentration hypothesis" provides the most conservative explanation for the occurrence of anthrax under the observed conditions. PMID:8548686

Gates, C C; Elkin, B T; Dragon, D C

1995-10-01

428

Experimental anthrax vaccines: efficacy of adjuvants combined with protective antigen against an aerosol Bacillus anthracis spore challenge in guinea pigs  

Microsoft Academic Search

The efficacy of several human anthrax vaccine candidates comprised of different adjuvants together with Bacillus anthracis protective antigen (PA) was evaluated in guinea pigs challenged by an aerosol of virulent B. anthracis spores. The most efficacious vaccines tested were formulated with PA plus monophosphoryl lipid A (MPL) in a squalenel lecithin\\/Tween 80 emulsion (SLT) and PA plus the saponin QS-21.

Bruce Ivins; Patricia Fellows; Louise Pitt; James Estep; Joseph Farchaus; Arthur Friedlander; Paul Gibbs

1995-01-01

429