Publications

label-free detection of b. anthracis spores using a surface plasmon resonance biosensor.	this study demonstrates the first use of surface plasmon resonance (spr) technology for the rapid, sensitive and label-free detection of whole b. anthracis spores. the approach involves the use of an spr biosensor (biacore 3000), and a monoclonal antibody which was raised against the b. anthracis spore (mab 8g3). by means of subtractive inhibition assays, whole b. anthracis spores with concentrations as low as 10(4) colony-forming units (cfu) ml(-1) can be detected within 40 min, and other relat ...	2009	19305924
structure and complexity of a bacterial transcriptome.	although gene expression has been studied in bacteria for decades, many aspects of the bacterial transcriptome remain poorly understood. transcript structure, operon linkages, and information on absolute abundance all provide valuable insights into gene function and regulation, but none has ever been determined on a genome-wide scale for any bacterium. indeed, these aspects of the prokaryotic transcriptome have been explored on a large scale in only a few instances, and consequently little is kn ...	2009	19304856
distribution, diversity, and potential mobility of extrachromosomal elements related to the bacillus anthracis pxo1 and pxo2 virulence plasmids.	the presence of a pxo1- and/or pxo2-like plasmid(s) in clinical isolates of bacillus cereus sensu stricto and in strains of the biopesticide bacillus thuringiensis has been reported recently, and the pxo2-like plasmid pbt9727 and another pxo2-like plasmid, paw63, were found to be conjugative. in this study, a total of 1,000 b. cereus group isolates were analyzed for the presence of pxo1- and pxo2-like replicons and for the presence of pxo2-related conjugative modules. pxo1- and pxo2-like replico ...	2009	19304837
anthrax meningoencephalitis--declining trends in an uncommon but catastrophic cns infection in rural tamil nadu, south india.	anthrax, a cattle-born zoonosis has been a serious infectious disease and its meningoencephalitic form remains a rapidly fatal illness even now.	2009	19304297
efficacy of recombinant anthrax vaccine against bacillus anthracis aerosol spore challenge: preclinical evaluation in rabbits and rhesus monkeys.	this report describes the immunogenicity and protective efficacy of escherichia coli-expressed recombinant protective antigen (rpa) in new zealand white rabbits and rhesus macaques against an aerosol challenge with bacillus anthracis spores (ivri strain, tox+cap+). a dose-ranging study was performed in which it became evident that the level of anti-pa igg and toxin-neutralizing antibody titer was directly proportional to the dose of rpa administered. however, the onset time of primary and second ...	2009	19296443
comparative transcriptional profiling of bacillus cereus sensu lato strains during growth in co2-bicarbonate and aerobic atmospheres.	bacillus species are spore-forming bacteria that are ubiquitous in the environment and display a range of virulent and avirulent phenotypes. this range is particularly evident in the bacillus cereus sensu lato group; where closely related strains cause anthrax, food-borne illnesses, and pneumonia, but can also be non-pathogenic. although much of this phenotypic range can be attributed to the presence or absence of a few key virulence factors, there are other virulence-associated loci that are co ...	2009	19295911
biosecurity. paul keim on his life with the fbi during the anthrax investigation. interview by yudhijit bhattacharjee.		2009	19286527
pre-columbian origins for north american anthrax.	disease introduction into the new world during colonial expansion is well documented and had a major impact on indigenous populations; however, few diseases have been associated with early human migrations into north america. during the late pleistocene epoch, asia and north america were joined by the beringian steppe ecosystem which allowed animals and humans to freely cross what would become a water barrier in the holocene. anthrax has clearly been shown to be dispersed by human commerce and t ...	2009	19283072
[fluoroquinolones: antimicrobial activity and chemotherapeutic efficacy with respect to various pathogens in highly dangerous diseases].	comparative in vitro and in vivo efficacy of new fluoroquinolones with respect to pathogens of tularemia, glanders, melioidosis and anthrax was estimated. it was shown that the strains of the tularemia, glanders, melioidosis and anthrax pathogens were in vitro highly susceptible to the new agents. the experiments on laboratory animals demonstrated that pefloxacin and sparfloxacin had extremely broad spectra and were of special value in emergency prophylaxis of tularemia, glanders, melioidosis an ...	2007	19275053
bryan krantz: from folding to unfolding proteins. interview by liz savage.		2009	19273611
anthrax edema toxin induces maturation of dendritic cells and enhances chemotaxis towards macrophage inflammatory protein 3beta.	bacillus anthracis secretes two bipartite toxins, edema toxin (et) and lethal toxin (lt), which impair immune responses and contribute directly to the pathology associated with the disease anthrax. edema factor, the catalytic subunit of et, is an adenylate cyclase that impairs host defenses by raising cellular cyclic amp (camp) levels. synthetic camp analogues and compounds that raise intracellular camp levels lead to phenotypic and functional changes in dendritic cells (dcs). here, we demonstra ...	2009	19273556
pathophysiology of anthrax.	infection by bacillus anthracis in animals and humans results from accidental or intentional exposure, by oral, cutaneous or pulmonary routes, to spores, which are normally present in the soil. treatment includes administration of antibiotics, vaccination or treatment with antibody to the toxin. a better understanding of the molecular basis of the processes involved in the pathogenesis of anthrax namely, spore germination in macrophages and biological effects of the secreted toxins on heart and ...	2009	19273366
anthrax toxin: pathologic effects on the cardiovascular system.	anthrax is a disease caused by infection with spores from the bacteria bacillus anthracis. after entering the body, the spores germinate into bacteria and secrete a toxin that causes local edema and, in systemic infections, cardiovascular collapse and death. the toxin is a tripartite polypeptide, consisting of protective antigen (pa), lethal factor (lf) and edema factor (ef), which have key roles in the bacterial pathogenesis and disease progression. pa facilitates transfer of lf and ef to the c ...	2009	19273204
lung epithelial injury by b. anthracis lethal toxin is caused by mkk-dependent loss of cytoskeletal integrity.	bacillus anthracis lethal toxin (lt) is a key virulence factor of anthrax and contributes significantly to the in vivo pathology. the enzymatically active component is a zn(2+)-dependent metalloprotease that cleaves most isoforms of mitogen-activated protein kinase kinases (mkks). using ex vivo differentiated human lung epithelium we report that lt destroys lung epithelial barrier function and wound healing responses by immobilizing the actin and microtubule network. long-term exposure to the to ...	2009	19270742
the anthrax vaccine: no new tricks for an old dog.	the original license for production of the anthrax vaccine, anthrax vaccine adsorbed (ava), was issued in 1970. since that time, over 8 million ava immunizations have been administered to 2+ million individuals. in 2002, the national academy of sciences, institute of medicine, reviewed the safety and efficacy of ava. they concluded that the vaccine is acceptably safe and effective in protecting humans against anthrax. the vaccine should protect people against all known strains of anthrax bacteri ...	2009	19270504
secondary cell wall polysaccharides of bacillus anthracis are antigens that contain specific epitopes which cross-react with three pathogenic bacillus cereus strains that caused severe disease, and other epitopes common to all the bacillus cereus strains tested.	the immunoreactivities of hydrogen fluoride (hf)-released cell wall polysaccharides (hf-pss) from selected bacillus anthracis and bacillus cereus strains were compared using antisera against live and killed b. anthracis spores. these antisera bound to the hf-pss from b. anthracis and from three clinical b. cereus isolates (g9241, 03bb87, and 03bb102) obtained from cases of severe or fatal human pneumonia but did not bind to the hf-pss from the closely related b. cereus atcc 10987 or from b. cere ...	2009	19270075
sortase d forms the covalent bond that links bcpb to the tip of bacillus cereus pili.	bacillus cereus and other gram-positive bacteria elaborate pili via a sortase d-catalyzed transpeptidation mechanism from major and minor pilin precursor substrates. after cleavage of the lpxtg sorting signal of the major pilin, bcpa, sortase d forms an amide bond between the c-terminal threonine and the amino group of lysine within the ypkn motif of another bcpa subunit. pilus assembly terminates upon sortase a cleavage of the bcpa sorting signal, resulting in a covalent bond between bcpa and t ...	2009	19269972
reduced expression of cd45 protein-tyrosine phosphatase provides protection against anthrax pathogenesis.	the modulation of cellular processes by small molecule inhibitors, gene inactivation, or targeted knockdown strategies combined with phenotypic screens are powerful approaches to delineate complex cellular pathways and to identify key players involved in disease pathogenesis. using chemical genetic screening, we tested a library of known phosphatase inhibitors and identified several compounds that protected bacillus anthracis infected macrophages from cell death. the most potent compound was ass ...	2009	19269962
the adenylate cyclase toxins of bacillus anthracis and bordetella pertussis promote th2 cell development by shaping t cell antigen receptor signaling.	the adjuvanticity of bacterial adenylate cyclase toxins has been ascribed to their capacity, largely mediated by camp, to modulate apc activation, resulting in the expression of th2-driving cytokines. on the other hand, camp has been demonstrated to induce a th2 bias when present during t cell priming, suggesting that bacterial camp elevating toxins may directly affect the th1/th2 balance. here we have investigated the effects on human cd4(+) t cell differentiation of two adenylate cyclase toxin ...	2009	19266022
enantioselective desymmetrisation of citric acid catalysed by the substrate-tolerant petrobactin biosynthetic enzyme asba.	asba catalyses the highly enantioselective desymmetrisation of citric acid via atp-dependent condensation with spermidine, as well as the condensation of citric acid with several spermidine analogues and the condensation of the citric acid analogue tricarballylic acid with spermidine, suggesting that it may be a useful biocatalyst for asymmetric synthesis.	2009	19259597
statistical scales of order in dna.	in the present paper we examine the statistics of occurrence of a-t and c-g base pairs in dna. we focus on the net base composition in blocks of base pairs of various sizes. this paper extends our previous work on randomness and order in dna sequences and examines order on various scales. for structure on the local scale (10(0)-10(1) bp) we have seen that the net base composition in given block sizes is fitted very accurately by the discrete binomial distribution for a random system. if the stat ...	2009	19254822
anthrax, toxins and vaccines: a 125-year journey targeting bacillus anthracis.	bacillus anthracis is the causative agent of anthrax, a disease that plagues both humans and various animal species. effective vaccines are available, but those approved for human use are crude culture supernatants that require multiple injections and a yearly boost. many experts agree that it is now time for the next generation of human vaccines against anthrax. accordingly, this review will succinctly focus upon: pathogenesis of b. anthracis, with particular emphasis upon the immune system; th ...	2009	19254170
siderophore-mediated iron acquisition systems in bacillus cereus: identification of receptors for anthrax virulence-associated petrobactin .	during growth under iron limitation, bacillus cereus and bacillus anthracis, two human pathogens from the bacillus cereus group of gram-positive bacteria, secrete two siderophores, bacillibactin (bb) and petrobactin (pb), for iron acquisition via membrane-associated substrate-binding proteins (sbps) and other abc transporter components. since pb is associated with virulence traits in b. anthracis, the pb-mediated iron uptake system presents a potential target for antimicrobial therapies; its cha ...	2009	19254027
self-assembled peptide monolayers as a toxin sensing mechanism within arrayed microchannels.	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, sam ...	2009	19253949
isolation of full-length igg antibodies from combinatorial libraries expressed in escherichia coli.	we have developed a technology for the facile isolation of full-length igg antibodies with desired specificity from combinatorial libraries expressed in escherichia coli. full-length heavy and light chains are expressed from a bicistronic operon and are secreted into the periplasm where they assemble into aglycosylated iggs that are fully functional for antigen binding. expression of an inner membrane-tethered fc-binding protein is used to capture the igg molecules and anchor them to the cell. f ...	2009	19252859
the danger of lime use in agricultural anthrax disinfection procedures: the potential role of calcium in the preservation of anthrax spores.	previously, lime (calcium oxide) was recommended by the canadian food inspection agency (cfia) as an anthrax disinfectant. however, a recent scientific review of the subject has found evidence to suggest that exposure of anthrax spores to calcium may aid in their survival and viability. for this reason, the cfia no longer recommends the use of lime for agricultural anthrax disinfection.	2008	19252713
dendritic cell targeting of bacillus anthracis protective antigen expressed by lactobacillus acidophilus protects mice from lethal challenge.	efficient vaccines potentiate antibody avidity and increase t cell longevity, which confer protection against microbial lethal challenge. a vaccine strategy was established by using lactobacillus acidophilus to deliver bacillus anthracis protective antigen (pa) via specific dendritic cell-targeting peptides to dendritic cells (dcs), which reside in the periphery and mucosal surfaces, thus directing and regulating acquired immunity. the efficiency of oral delivery of l. acidophilus expressing a p ...	2009	19246373
norepinephrine increases blood pressure but not survival with anthrax lethal toxin in rats.	the response of anthrax lethal toxin (letx) induced shock and lethality to conventional therapies has received little study. previously, fluids worsened outcome in letx-challenged rats in contrast to its benefit with lipopolysaccharide (lps) or escherichia coli. the current study investigated norepinephrine treatment.	2009	19242337
crystal structure of the bacillus anthracis nucleoside diphosphate kinase and its characterization reveals an enzyme adapted to perform under stress conditions.	nucleoside diphosphate kinases (ndks) play an important role in a plethora of regulatory and metabolic functions. inhibition of the b. anthracis ndk mrna results in the formation of nonviable aberrant spores. we report the characterization and crystal structure of the enzyme from b. anthracis nucleoside diphosphate kinase (bandk), the first from sporulating bacteria. the enzyme, although from a mesophilic source, is active at extremes of ph (3.5-10.5), temperature (10-95 degrees c) and ionic str ...	2009	19241473
cutaneous anthrax, west bengal, india, 2007.		2009	19239777
hydroxylamine-amplified gold nanoparticles for the naked eye and chemiluminescent detection of sequence-specific dna with notable potential for single-nucleotide polymorphism discrimination.	herein, we report a hydroxylamine-amplified gold nanoparticle-based assay with naked eye and chemiluminescent (cl) detection of sequence-specific dna. for the naked eye detection assay, the signal can be observed by naked eye directly, which provides a general way for other biological assays. in contrast, the cl detection method can improve the detection limit by two orders of magnitude as compared to the naked eye detection, and a limit as low as 10 amol of target dna can be sensitively detecte ...	2009	19238286
livestock keeper perceptions of four indigenous cattle breeds in tsetse infested areas of ethiopia.	four cattle breeds indigenous to western and south-western ethiopia--abigar, gurage, horro and sheko--were included in a study of the perceptions of smallholder cattle keepers regarding cattle management, production levels and constraints for production. a semi-structured questionnaire was used and 60 cattle keepers from each of the four areas were interviewed. diseases were reported as the main constraint to cattle production by a majority of livestock keepers in all areas except in the sheko a ...	2009	19234873
the tubulin-like repx protein encoded by the pxo1 plasmid forms polymers in vivo in bacillus anthracis.	bacillus anthracis contains two megaplasmids, pxo1 and pxo2, that are critical for its pathogenesis. stable inheritance of pxo1 in b. anthracis is dependent upon the tubulin/ftsz-like repx protein encoded by this plasmid. previously, we have shown that repx undergoes gtp-dependent polymerization in vitro. however, the polymerization properties and localization pattern of repx in vivo are not known. here, we utilize a repx-green fluorescent protein (gfp) fusion to show that repx forms foci and th ...	2009	19233922
structural and chemical basis for glucosamine 6-phosphate binding and activation of the glms ribozyme.	the glms ribozyme is the first naturally occurring catalytic rna that relies on an exogenous, nonnucleotide cofactor for reactivity. from a biochemical perspective, the glms ribozyme derived from bacillus anthracis is the best characterized. however, much of the structural work to date has been done on a variant glms ribozyme, derived from thermoanaerobacter tengcongensis. here we present structures of the b. anthracis glms ribozyme in states before the activating sugar, glucosamine 6-phosphate ...	2009	19228039
[research and development policy on bioterrorism medical countermeasures in the united states].	the united states department of health and human services (dhhs) plays a key role in biodefense, which accounts for almost 80% of the u.s. civilian biodefense budget, which itself has amount to over 500 billion yen a year since the 2001 anthrax mailings and has involved programs based on the hspd-10 "biodefense for the 21st century". to promote r&d on medical countermeasures, the dhhs has invested in basic research and ensuring market, and closely communicated with stakeholders to overcome r&d b ...	2009	19227217
immuno-detection of anthrose containing tetrasaccharide in the exosporium of bacillus anthracis and bacillus cereus strains.	bacillus anthracis strains of various origins were analysed with the view to describe intrinsic and persistent structural components of the bacillus collagen-like protein of anthracis glycoprotein associated anthrose containing tetrasaccharide in the exosporium.	2009	19226390
frequency and domain specificity of toxin-neutralizing paratopes in the human antibody response to anthrax vaccine adsorbed.	protective antigen (pa) is the cell surface recognition unit of the binary anthrax toxin system and the primary immunogenic component in both the current and proposed "next-generation" anthrax vaccines. several studies utilizing animal models have indicated that pa-specific antibodies, acquired by either active or passive immunization, are sufficient to protect against infection with bacillus anthracis. to investigate the human antibody response to anthrax immunization, we have established a lar ...	2009	19223482
two small c-type cytochromes affect virulence gene expression in bacillus anthracis.	regulated expression of the genes for anthrax toxin proteins is essential for the virulence of the pathogenic bacterium bacillus anthracis. induction of toxin gene expression depends on several factors, including temperature, bicarbonate levels, and metabolic state of the cell. to identify factors that regulate toxin expression, transposon mutagenesis was performed under non-inducing conditions and mutants were isolated that untimely expressed high levels of toxin. a number of these mutations cl ...	2009	19222757
dynamics and energetics: a consensus analysis of the impact of calcium on ef-cam protein complex.	we have studied the relationship between dynamical correlations and energetic contributions in an attempt to model the transmission of information inside protein-protein complexes. the complex formed between the edema factor (ef) of bacillus anthracis and calmodulin (cam) was taken as an example, as the formation and stability of the complex depend on the calcium complexation level. the effect of calcium through ef-cam residue network has been investigated with various approaches: 1), the elasti ...	2009	19217845
phylogeny in aid of the present and novel microbial lineages: diversity in bacillus.	bacillus represents microbes of high economic, medical and biodefense importance. bacillus strain identification based on 16s rrna sequence analyses is invariably limited to species level. secondly, certain discrepancies exist in the segregation of bacillus subtilis strains. in the rdp/ncbi databases, out of a total of 2611 individual 16s rdna sequences belonging to the 175 different species of the genus bacillus, only 1586 have been identified up to species level. 16s rrna sequences of bacillus ...	2009	19212464
identification of bacillus anthracis spore component antigens conserved across diverse bacillus cereus sensu lato strains.	we sought to identify proteins in the bacillus anthracis spore, conserved in other strains of the closely related bacillus cereus group, that elicit an immune response in mammals. two high throughput approaches were used. first, an in silico screening identified 200 conserved putative b. anthracis spore components. a total of 192 of those candidate genes were expressed and purified in vitro, 75 of which reacted with the rabbit immune sera generated against b. anthracis spores. the second approac ...	2009	19208616
pathogenic bacillus anthracis in the progressive gene losses and gains in adaptive evolution.	sequence mutations represent a driving force of adaptive evolution in bacterial pathogens. it is especially evident in reductive genome evolution where bacteria underwent lifestyles shifting from a free-living to a strictly intracellular or host-depending life. it resulted in loss-of-function mutations and/or the acquisition of virulence gene clusters. bacillus anthracis shares a common soil bacterial ancestor with its closely related bacillus species but is the only obligate, causative agent of ...	2009	19208130
anti-toxin antibodies in prophylaxis and treatment of inhalation anthrax.	the cdc recommend 60 days of oral antibiotics combined with a three-dose series of the anthrax vaccine for prophylaxis after potential exposure to aerosolized bacillus anthracis spores. the anthrax vaccine is currently not licensed for anthrax postexposure prophylaxis and has to be made available under an investigational new drug protocol. postexposure prophylaxis based on antibiotics can be problematic in cases where the use of antibiotics is contraindicated. furthermore, there is a concern tha ...	2009	19207098
nicotinamide mononucleotide synthetase is the key enzyme for an alternative route of nad biosynthesis in francisella tularensis.	enzymes involved in the last 2 steps of nicotinamide adenine dinucleotide (nad) cofactor biosynthesis, which catalyze the adenylylation of the nicotinic acid mononucleotide (namn) precursor to nicotinic acid dinucleotide (naad) followed by its amidation to nad, constitute promising drug targets for the development of new antibiotics. these enzymes, namn adenylyltransferase (gene nadd) and nad synthetase (gene nade), respectively, are indispensable and conserved in nearly all bacterial pathogens. ...	2009	19204287
evidence for a proton-protein symport mechanism in the anthrax toxin channel.	the toxin produced by bacillus anthracis, the causative agent of anthrax, is composed of three proteins: a translocase heptameric channel, (pa(63))(7), formed from protective antigen (pa), which allows the other two proteins, lethal and edema factors (lf and ef), to translocate across a host cell's endosomal membrane, disrupting cellular homeostasis. it has been shown that (pa(63))(7) incorporated into planar phospholipid bilayer membranes forms a channel capable of transporting lf and ef. prote ...	2009	19204186
involvement of tlr2 in innate response to bacillus anthracis infection.	the involvement of tlr2 receptor in the innate response to infection with bacillus anthracis was investigated. we studied the response to virulent or attenuated vollum strains in either in vitro assays using macrophage cultures, or in an in vivo model comparing the sensitivity of syrian hamster cells (expressing normal tlr2) to chinese hamster cells (lacking functional tlr2) to infection by the various b. anthracis strains. phagocytosis experiments with murine cell cultures or primary macrophage ...	2009	19201824
a case of pneumonia caused by bacillus anthracis secondary to gastrointestinal anthrax.	we present herein an unusual case of anthrax pneumonia secondary to gastrointestinal infection. in this case, severe abdominal pain occurred during the course of a stent placement procedure. the patient had undergone surgery with the prediagnosis of intestinal ischemia. on the second postoperative day, pneumonia developed and b. anthracis grew as the etiologic agent. pathological examination of small-bowel sections revealed findings in accordance with anthrax.	2009	19201638
evolution of pathogenicity in the bacillus cereus group.	the bacillus cereus group of bacteria comprises soil-dwelling saprophytes but on occasion these bacteria can cause a wide range of diseases in humans, including food poisoning, systemic infections and highly lethal forms of anthrax. while anthrax is almost invariably caused by strains from a single evolutionary lineage, bacillus anthracis, variation in the virulence properties of strains from other lineages has not been fully addressed. using multi-locus sequence data from 667 strains, we recons ...	2009	19200684
resistance of athymic nude mice to experimental cutaneous bacillus anthracis infection.	previous studies in a murine cutaneous anthrax model have demonstrated that hairless and haired hrs/j mice are extremely resistant to bacillus anthracis. because these mice are relatively thymus deficient, we used c57bl/6 athymic nude and euthymic mice to evaluate the relationship between t cell deficiency and this heightened resistance.	2009	19199545
genetic immunization with gpi-anchored anthrax protective antigen raises combined cd1d- and mhc ii-restricted antibody responses by natural killer t cell-mediated help.	studies have demonstrated that lipid rafts ultimately regulate the endocytosis of anthrax toxin via clathrin dependent pathway. interestingly, gpi-anchored protein rich rafts have also been shown to be transported down to the endocytic pathway to reducing late endosomes. taking advantage of this parallelism, we tried translating the anthrax toxin natural intoxication mechanism by administering a dna chimera that encoded protective antigen attached to a mammalian gpi-anchor sequence at its c-term ...	2009	19195490
expression, purification, crystallization and preliminary x-ray diffraction analysis of dihydrodipicolinate synthase from bacillus anthracis in the presence of pyruvate.	dihydrodipicolinate synthase (dhdps) catalyses the first committed step in the lysine-biosynthesis pathway in bacteria, plants and some fungi. in this study, the expression of dhdps from bacillus anthracis (ba-dhdps) and the purification of the recombinant enzyme in the absence and presence of the substrate pyruvate are described. it is shown that dhdps from b. anthracis purified in the presence of pyruvate yields greater amounts of recombinant enzyme with more than 20-fold greater specific acti ...	2009	19194017
biochemical characterization of alanine racemase--a spore protein produced by bacillus anthracis.	alanine racemase catalyzes the interconversion of l-alanine and d-alanine and plays a crucial role in spore germination and cell wall biosynthesis. in this study, alanine racemase produced by bacillus anthracis was expressed and purified as a monomer in escherichia coli and the importance of lysine 41 in the cofactor binding octapeptide and tyrosine 270 in catalysis was evaluated. the native enzyme exhibited an apparent k(m) of 3 mm for l-alanine, and a v(max) of 295 micromoles/min/mg, with the ...	2009	19192393
evaluation of ultrafiltration cartridges for a water sampling apparatus.	to determine the efficiency of various ultrafiltration cartridges (ufc) in concentrating test micro-organisms from drinking water.	2009	19191977
landscape phage as a molecular recognition interface for detection devices.	filamentous phages are thread-shaped bacterial viruses. their outer coat is a tube formed by thousands equal copies of the major coat protein pviii. libraries of random peptides fused to pviii domains were used for selection of phages probes specific for a panel of test antigens and biological threat agents. because the viral carrier in the phage borne bio-selective probes is infective, they can be cloned individually and propagated indefinitely without needs of their chemical synthesis or recon ...	2008	19190724
a combined immunomagnetic separation and lateral flow method for a sensitive on-site detection of bacillus anthracis spores--assessment in water and dairy products.	combination of immunomagnetic separation (ims) and lateral flow device (lfd) assays for the development of a sensitive, rapid, on-site methodology that enables concentration and detection of bacillus anthracis spores in complex samples.	2009	19187500
differential cell surface properties of vegetative bacillus.	the genus bacillus encompasses a wide range of species which display varying pathogenic abilities. the hydrophobicity of a range of bacillus species was determined to evaluate the correlation between bacterial hydrophobicity and pathogenicity.	2009	19187499
aptamer selection express: a novel method for rapid single-step selection and sensing of aptamers.	here we describe a new dna capture element (dce) sensing system, based on the quenching and dequenching of a double-stranded aptamer. this system shows very good sensitivity and thermal stability. while quenching, dequenching, and separating the dce systems made from different aptamers (all selected by selex), an alternative method to rapidly select aptamers was developed-the aptamer selection express (asexp). this process has been used to select aptamers against different types of targets (baci ...	2008	19183794
codon-optimized fluorescent proteins designed for expression in low-gc gram-positive bacteria.	fluorescent proteins have wide applications in biology. however, not all of these proteins are properly expressed in bacteria, especially if the codon usage and genomic gc content of the host organism are not ideal for high expression. in this study, we analyzed the dna sequences of multiple fluorescent protein genes with respect to codons and gc content and compared them to a low-gc gram-positive bacterium, bacillus anthracis. we found high discrepancies for cyan fluorescent protein (cfp), yell ...	2009	19181829
roles of germination-specific lytic enzymes cwlj and sleb in bacillus anthracis.	the structural characteristics of a spore enable it to withstand stresses that typically kill a vegetative cell. spores remain dormant until small molecule signals induce them to germinate into vegetative bacilli. germination requires degradation of the thick cortical peptidoglycan by germination-specific lytic enzymes (gsles). bacillus anthracis has four putative gsles, based upon sequence similarities with enzymes in other species: sleb, cwlj1, cwlj2, and slel. in this study, the roles of sleb ...	2009	19181808
anthrax protective antigen delivered by salmonella enterica serovar typhi ty21a protects mice from a lethal anthrax spore challenge.	bacillus anthracis, the etiological agent of anthrax disease, is a proven weapon of bioterrorism. currently, the only licensed vaccine against anthrax in the united states is ava biothrax, which, although efficacious, suffers from several limitations. this vaccine requires six injectable doses over 18 months to stimulate protective immunity, requires a cold chain for storage, and in many cases has been associated with adverse effects. in this study, we modified the b. anthracis protective antige ...	2009	19179420
antimicrobial effects of interferon-inducible cxc chemokines against bacillus anthracis spores and bacilli.	based on previous studies showing that host chemokines exert antimicrobial activities against bacteria, we sought to determine whether the interferon-inducible glu-leu-arg-negative cxc chemokines cxcl9, cxcl10, and cxcl11 exhibit antimicrobial activities against bacillus anthracis. in vitro analysis demonstrated that all three cxc chemokines exerted direct antimicrobial effects against b. anthracis spores and bacilli including marked reductions in spore and bacillus viability as determined using ...	2009	19179419
engineering antibody fragments to fold in the absence of disulfide bonds.	disulfide bonds play a critical role in the stabilization of the immunoglobulin beta-sandwich sandwich. under reducing conditions, such as those that prevail in the cytoplasm, disulfide bonds do not normally form and as a result most antibodies expressed in that compartment (intrabodies) accumulate in a misfolded and inactive state. we have developed a simple method for the quantitative isolation of antibody fragments that retain full activity under reducing conditions from large mutant librarie ...	2009	19177559
monitoring anthrax toxin receptor dissociation from the protective antigen by nmr.	the binding of the bacillus anthracis protective antigen (pa) to the host cell receptor is the first step toward the formation of the anthrax toxin, a tripartite set of proteins that include the enzymatic moieties edema factor (ef), and lethal factor (lf). pa is cleaved by a furin-like protease on the cell surface followed by the formation of a donut-shaped heptameric prepore. the prepore undergoes a major structural transition at acidic ph that results in the formation of a membrane spanning po ...	2009	19177347
cytotoxicity of bacterial-derived toxins to immortal lung epithelial and macrophage cells.	health risks associated with inhalation and deposition of biological materials have been a topic of great concern due to highly publicized cases of inhalation anthrax, of new regulations on the release of particulate matter, and to increased concerns on the hazards of indoor air pollution. here, we present an evaluation of the sensitivity of two immortal cell lines (a549, human lung carcinoma epithelia) and nr8383 (rat alveolar macrophages) to a variety of bacterial-derived inhalation hazards an ...	2010	19172232
the survivability of bacillus anthracis (sterne strain) in processed liquid eggs.	in this study, we investigated the survival and inactivation kinetics of a surrogate strain of bacillus anthracis (sterne strain) in whole egg (we), egg white (ew), sugared egg yolk (ysu), and salted egg yolk (ysa) at low (-20, 0, and 5 degrees c), moderate (15, 20, 25, 30, 35, and 40 degrees c), and high storage temperatures (45, 50, 55, and 60 degrees c). outgrowth of the spores was measured as lag phase duration (lpd). replication of vegetative cells was measured in terms of growth rate (gr) ...	2009	19171252
[cutaneous anthrax: seven cases].	anthrax is an acute infection caused by the gram-positive organism, bacillus anthracis, which rarely affects humans under normal conditions. depending on the mode of contamination, there are three distinct clinical forms: pulmonary, gastrointestinal and cutaneous. this type of infection is still common in the developing countries, a fact that should be borne in mind by examining doctors, and in particular by dermatologists. it is important to recognise the clinical aspects of this disease rarely ...	2009	19171223
thioamide hydroxypyrothiones supersede amide hydroxypyrothiones in potency against anthrax lethal factor.	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 th ...	2009	19170530
killed but metabolically active bacillus anthracis vaccines induce broad and protective immunity against anthrax.	bacillus anthracis is the causative agent of anthrax. we have developed a novel whole-bacterial-cell anthrax vaccine utilizing b. anthracis that is killed but metabolically active (kbma). vaccine strains that are asporogenic and nucleotide excision repair deficient were engineered by deleting the spoiie and uvrab genes, rendering b. anthracis extremely sensitive to photochemical inactivation with s-59 psoralen and uv light. we also introduced point mutations into the lef and cya genes, which all ...	2009	19168734
an approach to characterizing single-subunit mutations in multimeric prepores and pores of anthrax protective antigen.	heptameric pores formed by the protective antigen (pa) moiety of anthrax toxin translocate the intracellular effector moieties of the toxin across the endosomal membrane to the cytosol of mammalian cells. we devised a protocol to characterize the effects of individual mutations in a single subunit of heptameric pa prepores (pore precursors) or pores. we prepared monomeric pa containing a test mutation plus an innocuous cys-replacement mutation at a second residue (lys563, located on the external ...	2009	19165720
protective antigen composite nanofibers as a transdermal anthrax vaccine.	anthrax, a disease caused by the gram positive bacteria bacillus anthracis, has become an increasing threat to public health in the last several years, due to its use as an agent of biological warfare. the currently utilized human anthrax vaccine, which confers immunity through the host antibody recognition of protective antigen (pa), requires a three dose regimen and annual booster shots after the initial vaccination to maintain its efficacy. the long term goal of this project is to produce an ...	2008	19162840
seasonality of bacillus species isolated from blood cultures and its potential implications.	because they are rarely associated with actual infections, bacillus species are usually defined as contaminants. however, when isolated, they require precise laboratory identification and may influence treatment.	2009	19162377
the structure of rph, an exoribonuclease from bacillus anthracis, at 1.7 a resolution.	maturation of trna precursors into functional trna molecules requires trimming of the primary transcript at both the 5' and 3' ends. cleavage of nucleotides from the 3' stem of trna precursors, releasing nucleotide diphosphates, is accomplished in bacillus by a phosphate-dependent exoribonuclease, rph. the crystal structure of this enzyme from b. anthracis has been solved by molecular replacement to a resolution of 1.7 a and refined to an r factor of 19.3%. there is one molecule in the asymmetri ...	2009	19153445
antigen-specific human polyclonal antibodies from hyperimmunized cattle.	antigen-specific human polyclonal antibodies (hpabs), produced by hyperimmunization, could be useful for treating many human diseases. however, yields from available transgenic mice and transchromosomic (tc) cattle carrying human immunoglobulin loci are too low for therapeutic applications. we report a tc bovine system that produces large yields of hpabs. tc cattle were generated by transferring a human artificial chromosome vector carrying the entire unrearranged, human immunoglobulin heavy (hi ...	2009	19151699
stochastic gating and drug-ribosome interactions.	gentamicin is a potent antibiotic that is used in combination therapy for inhalation anthrax disease. the drug is also often used in therapy for methicillin-resistant staphylococcusaureus. gentamicin works by flipping a conformational switch on the ribosome, disrupting the reading head (i.e., 16s ribosomal decoding bases 1492-1493) used for decoding messenger rna. we use explicit solvent all-atom molecular simulation to study the thermodynamics of the ribosomal decoding site and its interaction ...	2009	19146858
caspase- and p53-dependent apoptosis in breast carcinoma cells induced by a synthetic selenadiazole derivative.	selenadiazole derivative is one kind of synthetic organoselenium compounds with potent and broad-spectrum antitumor activity. in this study, we showed that anthrax [1,2-c] [1,2,5] selenadiazolo-6,11-dione (asdo), an novel selenadiazole derivative, induced time- and dose-dependent apoptotic cell death in mcf-7 human breast carcinoma cells, as indicated by accumulation of sub-g1 cell population, dna fragmentation, nuclear condensation, caspase activation and parp cleavage. asdo-induced apoptosis w ...	2009	19146838
classification of select category a and b bacteria by fourier transform infrared spectroscopy.	fourier transform infrared (ft-ir) spectroscopy historically is a powerful tool for the taxonomic classification of bacteria by genus, species, and strain when they are grown under carefully controlled conditions. relatively few reports have investigated the determination and classification of pathogens such as the national institute of allergy and infectious diseases (niaid) category a bacillus anthracis spores and cells (ba), yersinia species, francisella tularensis (ft), and category b brucel ...	2009	19146715
bioterrorism for the respiratory physician.	terrorist attacks by definition are designed to cause fear and panic. there is no question that a terrorist attack using biological agents would present a grave threat to stability of the society in which they were released. early recognition of such a bioterrorist attack is crucial to containing the damage they could cause. as many of the most likely bioterrorism agents present with pulmonary disease, respiratory physicians may be crucial in the initial recognition and diagnosis phase, and cert ...	2009	19144044
rapid, high-throughput, culture-based pcr methods to analyze samples for viable spores of bacillus anthracis and its surrogates.	to rapidly remediate facilities after a biothreat agent release, improved turnaround times are needed for sample analysis. current methods to confirm the presence of a viable biothreat agent are limited by low sample throughput. we have developed a rapid-viability-polymerase chain reaction (rv-pcr) method to determine the presence of viable spores. the method combines high-throughput sample processing with 96-well pcr analysis, which measures a change in real-time, quantitative pcr response aris ...	2009	19141303
conservation in the face of diversity: multistrain analysis of an intracellular bacterium.	with the recent completion of numerous sequenced bacterial genomes, notable advances have been made in understanding the level of conservation between various species. however, relatively little is known about the genomic diversity among strains. we determined the complete genome sequence of the florida strain of anaplasma marginale, and near complete (>96%) sequences for an additional three strains, for comparative analysis with the previously fully sequenced st. maries strain genome.	2009	19134224
role of visible light-activated photocatalyst on the reduction of anthrax spore-induced mortality in mice.	photocatalysis of titanium dioxide (tio(2)) substrates is primarily induced by ultraviolet light irradiation. anion-doped tio(2) 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.	2009	19132100
detection of disease outbreaks by the use of oral manifestations.	oral manifestations of diseases caused by bioterrorist agents could be a potential data source for biosurveillance. this study had the objectives of determining the oral manifestations of diseases caused by bioterrorist agents, measuring the prevalence of these manifestations in emergency department reports, and constructing and evaluating a detection algorithm based on them. we developed a software application to detect oral manifestations in free text and identified positive reports over three ...	2009	19131324
anthrax protective antigen administered by dna vaccination to distinct subcellular locations potentiates humoral and cellular immune responses.	based on the hypothesis that immune outcome can be influenced by the form of antigen administered and its ability to access various antigen-processing pathways, we targeted the 63 kda fragment of protective antigen (pa) of bacillus anthracis to various subcellular locations by dna chimeras bearing a set of signal sequences. these targeting signals, namely, lysosome-associated membrane protein 1 (lamp1), tissue plasminogen activator (tpa) and ubiquitin, encoded various forms of pa viz. lysosomal, ...	2009	19130551
detection of anthrax toxin by an ultrasensitive immunoassay using europium nanoparticles.	we developed a europium nanoparticle-based immunoassay (enia) for the sensitive detection of anthrax protective antigen (pa). the enia exhibited a linear dose-dependent pattern within the detection range of 0.01 to 100 ng/ml and was approximately 100-fold more sensitive than enzyme-linked immunosorbent assay (elisa). false-positive results were not observed with serum samples from healthy adults, mouse plasma without pa, or plasma samples collected from mice injected with anthrax lethal factor o ...	2009	19129473
the listeria monocytogenes sortase-b recognizes varied amino acids at position 2 of the sorting motif.	sortases are bacterial enzymes that anchor surface proteins covalently to the peptidoglycan upon cleavage of a motif located at their c-terminal end. motifs recognized by sortases of the class-b (srtb) are defined by the consensus sequence np(q/k)(t/s)(n/g/s)(d/a). evidence supporting this consensus is limited to isdc of staphylococcus aureus and bacillus anthracis, cleaved at motifs npqtn and npktg, respectively. in listeria monocytogenes, strb has two substrates, lmo2185 and lmo2186, containin ...	2009	19129190
molecular modeling as a tool for drug discovery.	with the progression of structural genomics projects, comparative modeling remains an increasingly important method of choice to obtain 3d structure of proteins. it helps to bridge the gap between the available sequence and structure information by providing reliable and accurate protein models. comparative modeling based on more than 30% sequence identity is now approaching its natural template-based limits and further improvements require the development of effective refinement techniques capa ...	2008	19128219
anthrax lethal toxin triggers the formation of a membrane-associated inflammasome complex in murine macrophages.	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 approximately 200- and appr ...	2009	19124602
effects of anthrax lethal toxin on human primary keratinocytes.	to investigate the effects of anthrax lethal toxin (letx) on human primary keratinocytes.	2008	19120626
inflammasomes: guardians of cytosolic sanctity.	the innate immune system is critical in recognizing bacterial and viral infections to evoke a proper immune response. certain members of the intracellular nucleotide-binding and oligomerization domain (nod)-like receptor (nlr) family detect microbial components in the cytosol and trigger the assembly of large caspase-1-activating complexes termed inflammasomes. autoproteolytic maturation of caspase-1 zymogens within these inflammasomes leads to maturation and secretion of the pro-inflammatory cy ...	2009	19120479
the anthrax vaccine and research: reactions from postal workers and public health professionals.	during the 2001 anthrax attacks, public health agencies faced operational and communication decisions about the use of antibiotic prophylaxis and the anthrax vaccine with affected groups, including postal workers. this communication occurred within an evolving situation with incomplete and uncertain data. guidelines for prophylactic antibiotics changed several times, contributing to confusion and mistrust. at the end of 60 days of taking antibiotics, people were offered an additional 40 days' su ...	2008	19117431
[the dirty dozen].	the term "the dirty dozen" refers to the 12 biological agents such as, for example, the anthrax bacillus or botulinum toxin that could be used as biological weapons. even if their military use is considered unlikely physicians should be familiar with the problematic because these pathogens can also occur naturally or, respectively, cause disease as the consequence of a laboratory accident. it is of decisive importance to make the diagnosis as quickly as possible in order to limit any further spr ...	2009	19115185
efficacy of a vaccine based on protective antigen and killed spores against experimental inhalational anthrax.	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 formaldehyde-inactivated spores (fis) to pa (pa-fis) elicits total protection against cutaneous anthrax. nevertheless, vaccines that are effective against cutaneous anthrax may not be so ag ...	2009	19114543
extensive antibody cross-reactivity among infectious gram-negative bacteria revealed by proteome microarray analysis.	antibodies provide a sensitive indicator of proteins displayed by bacteria during sepsis. because signals produced by infection are naturally amplified during the antibody response, host immunity can be used to identify biomarkers for proteins that are present at levels currently below detectable limits. we developed a microarray comprising approximately 70% of the 4066 proteins contained within the yersinia pestis proteome to identify antibody biomarkers distinguishing plague from infections ca ...	2009	19112181
induction of autophagy by anthrax lethal toxin.	autophagy is an evolutionary conserved intracellular process whereby cells break down long-lived proteins and organelles. accumulating evidences suggest increasing physiological significance of autophagy in pathogenesis of infectious diseases. anthrax lethal toxin (lt) exerts its influence on numerous cells and herein, we report a novel effect of lt-induced autophagy on mammalian cells. several autophagy biochemical markers including lc3-ii conversion, increased punctuate distribution of gfp-lc3 ...	2009	19103170
mucosal immunization with attenuated salmonella enterica serovar typhi expressing protective antigen of anthrax toxin (pa83) primes monkeys for accelerated serum antibody responses to parenteral pa83 vaccine.	salmonella enterica serovar typhi vaccine strain cvd 908-htra was genetically engineered for stable plasmid-based expression of protective antigen of anthrax toxin (pa83) fused with the export protein clya (clya-pa83). the priming potential of cvd 908-htra expressing clya-pa83 was assessed in 12 rhesus and 20 cynomolgus macaques that were immunized mucosally (i.e., intranasally) on days 0 and 14. a parenteral booster with purified pa83 plus alum was given to rhesus macaques on days 42 and 225; c ...	2009	19099487
a short course of antibiotic treatment is effective in preventing death from experimental inhalational anthrax after discontinuing antibiotics.	postexposure prophylaxis of inhalational anthrax requires prolonged antibiotic therapy or antibiotics and vaccination. the duration of treatment for established anthrax is controversial, because retained spores may germinate and cause disease after antibiotics are discontinued. using rhesus macaques, we determined whether a short course of antibiotic treatment, as opposed to prophylaxis, could effectively treat inhalational anthrax and prevent disease caused by the germination of spores after di ...	2009	19099484
what is the relevance of lung epithelial cells during the dissemination of spores in inhalational anthrax?		2009	19098284
increased african-american involvement in vaccine studies.		2009	19095169
investigations and control measures following a case of inhalation anthrax in east london in a drum maker and drummer, october 2008.	the patient is believed to have acquired the infection from making animal hide drums. environmental investigations identified one drum and two pieces of animal skins contaminated with anthrax spores.	2008	19094916
how to extend the use of grid-based interaction energy maps from chemistry to biotopics.	many computational tools routinely used in chemistry could successfully be applied to the biosciences since protein-protein and protein-ligand interactions are governed by the laws of chemistry. this paper shows that it is possible to extend the use of existing computational tools from their traditional application field (e.g. chemistry) to culturally-related research areas by the implementation of simple but well-designed utilities. in particular, a computational strategy obtained by combining ...	2009	19085992
a genetic screen to identify bacteriophage lysins.	lysins are phage-encoded, peptidoglycan (cell wall) hydrolases that accumulate in the bacterial cytoplasm during a lytic infection cycle. late during infection, the lysins undergo holin-mediated translocation across the inner membrane into the peptidoglycan matrix where they cleave cell wall covalent bonds required for wall stability and allow bacterial lysis and progeny phage release. this potent hydrolytic activity is now the foundation of a powerful genetic-based screening process for the ide ...	2009	19082564