Poly-γ-d-Glutamic Acid Capsule Interferes with Lytic Infection of Bacillus anthracis by B. anthracis-Specific Bacteriophages

ABSTRACTThe poly-γ-d-glutamic acid capsule ofBacillus anthracisis a barrier to infection byB. anthracis-specific bacteriophages. Capsule expression was found to completely inhibit lytic infection by γ phage, an observation supported by the demonstration that this phage does not elaborate a hydrolase that would facilitate penetration through the protective capsule outer layer.

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Glutamate Racemase Mutants of Bacillus anthracis

Journal of Bacteriology ◽

10.1128/jb.00070-15 ◽

2015 ◽

Vol 197 (11) ◽

pp. 1854-1861 ◽

Cited By ~ 13

Author(s):

So-Young Oh ◽

Stefan G. Richter ◽

Dominique M. Missiakas ◽

Olaf Schneewind

Keyword(s):

Glutamic Acid ◽

Bacillus Anthracis ◽

Causative Agent ◽

Bacterial Growth ◽

Bacterial Infections ◽

Content Type ◽

Antibiotic Development ◽

Drug Candidates ◽

Glutamate Racemase ◽

Cell Shapes

ABSTRACTd-Glutamate is an essential component of bacterial peptidoglycan and a building block of the poly-γ-d-glutamic acid (PDGA) capsule ofBacillus anthracis, the causative agent of anthrax. Earlier work suggested that two glutamate racemases, encoded byracE1andracE2, are each essential for growth ofB. anthracis, supplyingd-glutamic acid for the synthesis of peptidoglycan and PDGA capsule. Earlier work could not explain, however, why two enzymes that catalyze the same reaction may be needed for bacterial growth. Here, we report that deletion ofracE1orracE2did not prevent growth ofB. anthracisSterne (pXO1+pXO2−), the noncapsulating vaccine strain, or ofB. anthracisAmes (pXO1+pXO2+), a fully virulent, capsulating isolate. While mutants with deletions inracE1andracE2were not viable,racE2deletion delayed vegetative growth ofB. anthracisfollowing spore germination and caused aberrant cell shapes, phenotypes that were partially restored by exogenousd-glutamate. Deletion ofracE1orracE2fromB. anthracisAmes did not affect the production or stereochemical composition of the PDGA capsule. A model is presented wherebyB. anthracis, similar toBacillus subtilis, utilizes two functionally redundant racemase enzymes to synthesized-glutamic acid for peptidoglycan synthesis.IMPORTANCEGlutamate racemases, enzymes that convertl-glutamate tod-glutamate, are targeted for antibiotic development. Glutamate racemase inhibitors may be useful for the treatment of bacterial infections such as anthrax, where the causative agent,B. anthracis, requiresd-glutamate for the synthesis of peptidoglycan and poly-γ-d-glutamic acid (PDGA) capsule. Here we show thatB. anthracispossesses two glutamate racemase genes that can be deleted without abolishing either bacterial growth or PDGA synthesis. These data indicate that drug candidates must inhibit both glutamate racemases, RacE1 and RacE2, in order to blockB. anthracisgrowth and achieve therapeutic efficacy.

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The Poly-γ-d-Glutamic Acid Capsule of Bacillus anthracis Enhances Lethal Toxin Activity

Infection and Immunity ◽

10.1128/iai.01145-10 ◽

2011 ◽

Vol 79 (9) ◽

pp. 3846-3854 ◽

Cited By ~ 29

Author(s):

Jeyoun Jang ◽

Minhui Cho ◽

Jeong-Hoon Chun ◽

Min-Hee Cho ◽

Jungchan Park ◽

...

Keyword(s):

Glutamic Acid ◽

Bacillus Anthracis ◽

Protective Antigen ◽

Immune Surveillance ◽

Lethal Toxin ◽

Mitogen Activated Protein Kinase ◽

Content Type ◽

Mitogen Activated Protein ◽

Anthrax Infection ◽

Processed Form

ABSTRACTThe poly-γ-d-glutamic acid (PGA) capsule is one of the major virulence factors ofBacillus anthracis, which causes a highly lethal infectious disease. The PGA capsule disguisesB. anthracisfrom immune surveillance and allows its unimpeded growth in the host. The PGA capsule recently was reported to be associated with lethal toxin (LT) in the blood of experimentally infected animals (M. H. Cho, et al., Infect. Immun. 78:387-392, 2010). The effect of PGA, either alone or in combination with LT, on macrophages, which play an important role in the progression of anthrax disease, has not been thoroughly investigated. In this study, we investigated the effect of PGA on LT cytotoxicity using the mouse macrophage cell line J774A.1. PGA produced a concentration-dependent enhancement of the cytotoxicity of LT on J774A.1 cells through an enhancement in the binding and accumulation of protective antigen to its receptors. The increase of LT activity was confirmed using Western blot analysis, which showed that the combination of PGA and LT produced a greater degree of degradation of mitogen-activated protein kinase kinases and an increased level of the activation of the proform of caspase-1 to its processed form compared to the effects of LT alone. In addition, mice that received a tail vein injection of both PGA and LT had a significantly increased rate of death compared to that of mice injected with LT alone. PGA had no effect when added to cultures or administered to mice in the absence of LT. These results emphasize the importance of PGA in the pathogenesis of anthrax infection.

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The Poly-γ-d-Glutamic Acid Capsule Surrogate of the Bacillus anthracis Capsule Is a Novel Toll-Like Receptor 2 Agonist

Infection and Immunity ◽

10.1128/iai.00888-15 ◽

2015 ◽

Vol 83 (10) ◽

pp. 3847-3856 ◽

Cited By ~ 13

Author(s):

Jun Ho Jeon ◽

Hae-Ri Lee ◽

Min-Hee Cho ◽

Ok-Kyu Park ◽

Jungchan Park ◽

...

Keyword(s):

Glutamic Acid ◽

Bacillus Anthracis ◽

Map Kinases ◽

Chinese Hamster Ovary Cells ◽

Mouse Bone Marrow ◽

Dependent Manner ◽

Toll Like Receptor ◽

Content Type ◽

Tnf Α ◽

Toll Like Receptor 2

Bacillus anthracisis a pathogenic Gram-positive bacterium that causes a highly lethal infectious disease, anthrax. The poly-γ-d-glutamic acid (PGA) capsule is one of the major virulence factors ofB. anthracis, along with exotoxins. PGA enablesB. anthracisto escape phagocytosis and immune surveillance. Our previous study showed that PGA activates the human macrophage cell line THP-1 and human dendritic cells, resulting in the production of the proinflammatory cytokine interleukin-1β (IL-1β) (M. H. Cho et al., Infect Immun 78:387–392, 2010,http://dx.doi.org/10.1128/IAI.00956-09). Here, we investigated PGA-induced cytokine responses and related signaling pathways in mouse bone marrow-derived macrophages (BMDMs) usingBacillus licheniformisPGA as a surrogate forB. anthracisPGA. Upon exposure to PGA, BMDMs produced proinflammatory mediators, including tumor necrosis factor alpha (TNF-α), IL-6, IL-12p40, and monocyte chemoattractant protein 1 (MCP-1), in a concentration-dependent manner. PGA stimulated Toll-like receptor 2 (TLR2) but not TLR4 in Chinese hamster ovary cells expressing either TLR2 or TLR4. The ability of PGA to induce TNF-α and IL-6 was retained in TLR4−/−but not TLR2−/−BMDMs. Blocking experiments with specific neutralizing antibodies for TLR1, TLR6, and CD14 showed that TLR6 and CD14 also were necessary for PGA-induced inflammatory responses. Furthermore, PGA enhanced activation of mitogen-activated protein (MAP) kinases and nuclear factor-kappa B (NF-κB), which are responsible for expression of proinflammatory cytokines. Additionally, PGA-induced TNF-α production was abrogated not only in MyD88−/−BMDMs but also in BMDMs pretreated with inhibitors of MAP kinases and NF-κB. These results suggest that immune responses induced by PGA occur via TLR2, TLR6, CD14, and MyD88 through activation of MAP kinase and NF-κB pathways.

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Galactosylation of the Secondary Cell Wall Polysaccharide ofBacillus anthracisand Its Contribution to Anthrax Pathogenesis

Journal of Bacteriology ◽

10.1128/jb.00562-17 ◽

2017 ◽

Vol 200 (5) ◽

Cited By ~ 7

Author(s):

Alice Chateau ◽

Justin Mark Lunderberg ◽

So Young Oh ◽

Teresa Abshire ◽

Arthur Friedlander ◽

...

Keyword(s):

Cell Wall ◽

Glutamic Acid ◽

Bacillus Anthracis ◽

Secondary Cell Wall ◽

Cell Wall Polysaccharide ◽

Wild Type ◽

Content Type ◽

Bacterial Inoculum ◽

Associated Proteins

ABSTRACTBacillus anthracis, the causative agent of anthrax disease, elaborates a secondary cell wall polysaccharide (SCWP) that is essential for bacterial growth and cell division.B. anthracisSCWP is comprised of trisaccharide repeats with the structure, [→4)-β-ManNAc-(1→4)-β-GlcNAc(O3-α-Gal)-(1→6)-α-GlcNAc(O3-α-Gal,O4-β-Gal)-(1→]6-12. The genes whose products promote the galactosylation ofB. anthracisSCWP are not yet known. We show here that the expression ofgalE1, encoding a UDP-glucose 4-epimerase necessary for the synthesis of UDP-galactose, is required forB. anthracisSCWP galactosylation. ThegalE1mutant assembles surface (S) layer and S layer-associated proteins that associate with ketal-pyruvylated SCWP via their S layer homology domains similarly to wild-typeB. anthracis, but the mutant displays a defect in γ-phage murein hydrolase binding to SCWP. Furthermore, deletion ofgalE1diminishes the capsulation ofB. anthraciswith poly-d-γ-glutamic acid (PDGA) and causes a reduction in bacterial virulence. These data suggest that SCWP galactosylation is required for the physiologic assembly of theB. anthraciscell wall envelope and for the pathogenesis of anthrax disease.IMPORTANCEUnlike virulentBacillus anthracisisolates,B. anthracisstrain CDC684 synthesizes secondary cell wall polysaccharide (SCWP) trisaccharide repeats without galactosyl modification, exhibits diminished growthin vitroin broth cultures, and is severely attenuated in an animal model of anthrax. To examine whether SCWP galactosylation is a requirement for anthrax disease, we generated variants ofB. anthracisstrains Sterne 34F2 and Ames lacking UDP-glucose 4-epimerase by mutating the genesgalE1andgalE2. We identifiedgalE1as necessary for SCWP galactosylation. Deletion ofgalE1decreased the poly-d-γ-glutamic acid (PDGA) capsulation of the vegetative form ofB. anthracisand increased the bacterial inoculum required to produce lethal disease in mice, indicating that SCWP galactosylation is indeed a determinant of anthrax disease.

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Bacillus anthracis poly-γ-d-glutamic acid (γDPGA)

Science-Business eXchange ◽

10.1038/scibx.2011.105 ◽

2011 ◽

Vol 4 (4) ◽

pp. 105-105

Keyword(s):

Glutamic Acid ◽

Bacillus Anthracis

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The Fluorocycline TP-271 Is Efficacious in Models of Aerosolized Bacillus anthracis Infection in BALB/c Mice and Cynomolgus Macaques

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01103-17 ◽

2017 ◽

Vol 61 (10) ◽

Cited By ~ 3

Author(s):

Trudy H. Grossman ◽

Michael S. Anderson ◽

Lindsay Drabek ◽

Melanie Gooldy ◽

Henry S. Heine ◽

...

Keyword(s):

Bacillus Anthracis ◽

Protective Antigen ◽

Day Treatment ◽

Inhalation Exposure ◽

Treated Group ◽

Average Dose ◽

Once Daily ◽

Content Type ◽

Cynomolgus Macaques ◽

Observation Period

ABSTRACT The fluorocycline TP-271 was evaluated in mouse and nonhuman primate (NHP) models of inhalational anthrax. BALB/c mice were exposed by nose-only aerosol to Bacillus anthracis Ames spores at a level of 18 to 88 lethal doses sufficient to kill 50% of exposed individuals (LD50). When 21 days of once-daily dosing was initiated at 24 h postchallenge (the postexposure prophylaxis [PEP] study), the rates of survival for the groups treated with TP-271 at 3, 6, 12, and 18 mg/kg of body weight were 90%, 95%, 95%, and 84%, respectively. When 21 days of dosing was initiated at 48 h postchallenge (the treatment [Tx] study), the rates of survival for the groups treated with TP-271 at 6, 12, and 18 mg/kg TP-271 were 100%, 91%, and 81%, respectively. No deaths of TP-271-treated mice occurred during the 39-day posttreatment observation period. In the NHP model, cynomolgus macaques received an average dose of 197 LD50 of B. anthracis Ames spore equivalents using a head-only inhalation exposure chamber, and once-daily treatment of 1 mg/kg TP-271 lasting for 14 or 21 days was initiated within 3 h of detection of protective antigen (PA) in the blood. No (0/8) animals in the vehicle control-treated group survived, whereas all 8 infected macaques treated for 21 days and 4 of 6 macaques in the 14-day treatment group survived to the end of the study (56 days postchallenge). All survivors developed toxin-neutralizing and anti-PA IgG antibodies, indicating an immunologic response. On the basis of the results obtained with the mouse and NHP models, TP-271 shows promise as a countermeasure for the treatment of inhalational anthrax.

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Design of polyester-elastane-cotton plated knitted components for hot and dry environment

International Journal of Clothing Science and Technology ◽

10.1108/ijcst-10-2017-0155 ◽

2018 ◽

Vol 30 (5) ◽

pp. 657-667

Author(s):

Varadaraju Ramakrishnan ◽

Srinivasan Jagannathan

Keyword(s):

Outer Layer ◽

Linear Density ◽

Moisture Transfer ◽

Contact Layer ◽

Cotton Yarn ◽

Heat And Moisture Transfer ◽

Polyester Yarn ◽

Content Type ◽

Skin Contact ◽

Heat And Moisture

Purpose The purpose of this paper is to optimize the linear densities of polyester yarn and filament for inner layer and elastane for middle layer with cotton yarn outer layer in plain knitted plated structure for hot and dry environment clothing. Design/methodology/approach Three levels of polyester yarn linear densities (11.1, 8.4 and 5.6 Tex), filament linear densities (0.8, 1.55 and 2.3 Decitex) and elastane (0, 4 and 8 percent) with 14.75 Tex cotton yarn have been used to knit 15 single jersey plated fabrics based on Box and Benhens experimental design with same loop length. Three cotton–elastane core-spun fabrics were also produced. All the fabrics were analyzed for moisture and ergonomic comfort properties and wet fabric coefficient of friction. Findings The increase in elastane content and yarn linear density decreases water vapor and air permeability; the increase in filament linear density decreases wicking rate and water absorbency. The optimum solution is 5.55 Tex polyester yarn of 0.8 Decitex filament as inner layer and 14.75 Tex cotton yarn as outer layer which gives good heat and moisture transfer without stickiness. Research limitations/implications The implication of this paper is to study thinner polyester, polypropylene and polyethylene fabrics with more micro pores as skin contact layer for quicker heat and moisture transfer. Practical implications Outward wickability of sweat from the skin is the prime requirement of all skin contact layer fabrics. Social implications It shifts the social attitude of most comfortable fabric to polyester–cotton plated for hot and dry climate. Originality/value This paper employs a more practical method for the selection of fabric.

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Bioterrorism: Lessons Learned Since the Anthrax Mailings

mBio ◽

10.1128/mbio.00232-11 ◽

2011 ◽

Vol 2 (6) ◽

Cited By ~ 9

Author(s):

Michael J. Imperiale ◽

Arturo Casadevall

Keyword(s):

United States ◽

Bacillus Anthracis ◽

Life Science ◽

Science Research ◽

The United States ◽

September 11 ◽

Lessons Learned ◽

Content Type ◽

Risks And Benefits ◽

September 11 Attacks

ABSTRACT In the fall of 2001, Bacillus anthracis spores were spread through letters mailed in the United States. Twenty-two people are known to have been infected, and five of these individuals died. Together with the September 11 attacks, this resulted in a reevaluation of the risks and benefits of life science research with the potential for misuse. In this editorial, we review some of the results of these discussions and their implications for the future.

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Bovine Bacillus anthracis in Cameroon

Applied and Environmental Microbiology ◽

10.1128/aem.00074-11 ◽

2011 ◽

Vol 77 (16) ◽

pp. 5818-5821 ◽

Cited By ~ 16

Author(s):

Paola Pilo ◽

Alexandra Rossano ◽

Hamadou Bamamga ◽

Souley Abdoulkadiri ◽

Vincent Perreten ◽

...

Keyword(s):

Bacillus Cereus ◽

Bacillus Anthracis ◽

Content Type ◽

Western Africa

ABSTRACTBovineBacillus anthracisisolates from Cameroon were genetically characterized. They showed a strong homogeneity, and they belong, together with strains from Chad, to cluster Aβ, which appears to be predominant in western Africa. However, one strain that belongs to a newly defined clade (D) and cluster (D1) is penicillin resistant and shows certain phenotypes typical ofBacillus cereus.

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