Molecular investigation of the Aum Shinrikyo anthrax release in Kameido, Japan

Anthrax revisited: how assessing the unpredictable can improve biosecurity

B. anthracis is one of the most often weaponized pathogens. States had it in their bioweapons programs and criminals and terrorists have used or attempted to use it. This study is motivated by the narrative that emerging and developing technologies today contribute to the amplification of danger through greater easiness, accessibility and affordability of steps in the making of an anthrax weapon. As states would have way better preconditions if they would decide for an offensive bioweapons program, we focus on bioterrorism. This paper analyzes and assesses the possible bioterrorism threat arising from advances in synthetic biology, genome editing, information availability, and other emerging, and converging sciences and enabling technologies. Methodologically we apply foresight methods to encourage the analysis of contemporary technological advances. We have developed a conceptual six-step foresight science framework approach. It represents a synthesis of various foresight methodologies including literature review, elements of horizon scanning, trend impact analysis, red team exercise, and free flow open-ended discussions. Our results show a significant shift in the threat landscape. Increasing affordability, widespread distribution, efficiency, as well as ease of use of DNA synthesis, and rapid advances in genome-editing and synthetic genomic technologies lead to an ever-growing number and types of actors who could potentially weaponize B. anthracis. Understanding the current and future capabilities of these technologies and their potential for misuse critically shapes the current and future threat landscape and underlines the necessary adaptation of biosecurity measures in the spheres of multi-level political decision making and in the science community.

Evaluation of Sporicidal Disinfectants for the Disinfection of Personal Protective Equipment During Biological Hazards

A fast, effective, and safe disinfection of personal protective equipment (PPE) is vitally important for emergency forces involved in biological hazards. This study aimed to investigate a broad range of disinfectants to improve the established disinfection procedure. We analyzed the efficacy of chlorine-, peracetic acid–, and oxygen-based disinfectants against Bacillus spores on PPE. Therefore, spores of different Bacillus species were exposed to disinfectants on PPE material by using a standardized procedure covering the dried spores with disinfectants and applying mechanical distribution. Efficacy of disinfectants was quantified by determining the reduction factor (log₁₀ levels) and number of viable spores left afterward. The chlorine-based granulate Hypochlorit CA G (2% chlorine) sufficiently inactivated Bacillus spores of risk groups 1 and 2, even with temperatures ranging from −20 to 35°C. Wofasteril^® SC super (1.75% peracetic acid) achieved a reliable reduction of risk groups 1 and 2 and even fully virulent Bacillus spores by ≥5 log₁₀ levels on PPE. With this, Hypochlorit-CA G and Wofasteril^® SC super proved to be promising alternatives to the previously proven and widely used peracetic acid compound Wofasteril^® (2% peracetic acid) for the disinfection of PPE when bacterial spores are known to be the contaminating agent. These results will help to improve the disinfection of PPE during biological hazards by providing new data on promising alternative compounds.

A fast, effective, and safe disinfection of personal protective equipment (PPE) is vitally important for emergency forces involved in biological hazards. This study aimed to investigate a broad range of disinfectants to improve the established disinfection procedure. The authors analyzed the efficacy of chlorine-, peracetic acid-, and oxygen-based disinfectants against Bacillus spores on PPE.

Current State of Anthrax Vaccines and Key R&D Gaps Moving Forward

A licensed anthrax vaccine has been available for pre-exposure prophylaxis in the United States since 1970, and it was approved for use as a post-exposure prophylaxis, in combination with antibiotic treatment, in 2015. A variety of other vaccines are available in other nations, approved under various regulatory frameworks. However, investments in anthrax vaccines continue due to the severity of the threat posed by this bacterium, as both a naturally occurring pathogen and the potential for use as a bioweapon. In this review, we will capture the current landscape of anthrax vaccine development, focusing on those lead candidates in clinical development. Although approved products are available, a robust pipeline of candidate vaccines are still in development to try to address some of the key research gaps in the anthrax vaccine field. We will then highlight some of the most pressing needs in terms of anthrax vaccine research.

QSAR and molecular docking studies of lethal factor protease inhibitors against Bacillus anthracis

Bacillus anthracis is considered as a biological warfare agent because it is the causative agent of the serious infectious anthrax disease. Delay in treatment leads to lethal factor-mediated toxaemia which is very critical due to lack of therapeutic options. Consequently, attempts have been made to discover potent lethal factor (LF) protease inhibitors such as small-molecule synthetic 2-thio-1,3-thiazolidine-4-one (rhodanine) compounds. But computed descriptor-based quantitative structure-activity relationship (QSAR) and drug design studies on such aspect are poorly represented. Therefore, an attempt was made for developing QSAR models using structural descriptors for 1,3-thiazolidine-4-one compounds. The models were developed on a series of 49 LF protease inhibitors using the combination of constitutional, functional group, atom-centred fragment and molecular property descriptors. The best QSAR model included four variables, namely, C-040, nR05, GVWAI-80 and ALOGP that correlated well with the anti-LF protease activity with a good correlation coefficient (r = 0.870) of good statistical significance (F_{4, 29} = 14.09 (α = 0.001) F_{4, 29} = 6.19). This model was also validated and explained 58.1% of variances of the Bacillus anthracis inhibitory activities of the studied compounds with r²_pred = 0.710 which denotes external predictability. Finally, molecular docking was carried out to predict the mode of binding of some highly active congeneric compounds. It was shown that VAL 1403 is an important residue for phenyl ring. TYR 1456 and HIS 1418 are responsible for interaction with the rhodanine nucleus. Therefore, these residues are considered responsible for the inhibition of LF protease anthrax and can predict significant dimension of essential structural features of these inhibitors to evaluate, screen and help priorities of the synthesis of the candidates against anthrax bioterrorism.

Offline Next Generation Metagenomics Sequence Analysis Using MinION Detection Software (MINDS)

Field laboratories interested in using the MinION often need the internet to perform sample analysis. Thus, the lack of internet connectivity in resource-limited or remote locations renders downstream analysis problematic, resulting in a lack of sample identification in the field. Due to this dependency, field samples are generally transported back to the lab for analysis where internet availability for downstream analysis is available. These logistics problems and the time lost in sample characterization and identification, pose a significant problem for field scientists. To address this limitation, we have developed a stand-alone data analysis packet using open source tools developed by the Nanopore community that does not depend on internet availability. Like Oxford Nanopore Technologies’ (ONT) cloud-based What’s In My Pot (WIMP) software, we developed the offline MinION Detection Software (MINDS) based on the Centrifuge classification engine for rapid species identification. Several online bioinformatics applications have been developed surrounding ONT’s framework for analysis of long reads. We have developed and evaluated an offline real time classification application pipeline using open source tools developed by the Nanopore community that does not depend on internet availability. Our application has been tested on ATCC’s 20 strain even mix whole cell (ATCC MSA-2002) sample. Using the Rapid Sequencing Kit (SQK-RAD004), we were able to identify all 20 organisms at species level. The analysis was performed in 15 min using a Dell Precision 7720 laptop. Our offline downstream bioinformatics application provides a cost-effective option as well as quick turn-around time when analyzing samples in the field, thus enabling researchers to fully utilize ONT’s MinION portability, ease-of-use, and identification capability in remote locations.

Non-contact and non-destructive detection and identification of Bacillus anthracis inside paper envelopes

Efficient and safe detection of Bacillus anthracis spores (BAS) is a challenging task especially in bio-terror scenarios where the agent is concealed. We provide a proof-of-concept for the identification of concealed BAS inside mail envelopes using short-wave infrared hyperspectral imaging (SWIR-HSI). The spores and two other benign materials are identified according to their typical absorption spectrum. The identification process is based on the removal of the envelope signal using a new automatic new algorithm. This method may serve as a fast screening tool prior to using classical bioanalytical techniques.

Establishment of a National Inventory of Dangerous Pathogens in the Republic of Uganda

One of the challenges of global biosecurity is to protect and control dangerous pathogens from unauthorized access and intentional release. A practical and feasible option to protect life science institutes against theft and sabotage, and secure their biological materials against misuse, is to establish a national electronic database with a comprehensive overview of the locations of all controlled dangerous pathogens in a country. This national database could be used as an instrument to secure and account for dangerous pathogens in a country, but it could also assist in establishing a biosecurity assessing and monitoring system for laboratories that work with these controlled biological agents. The Republic of Uganda is one of the first countries, prompted by the World Health Organization's (WHO's) Joint External Evaluation (JEE), to implement a national electronic database that assembles information collected from relevant Ugandan laboratories. This Ugandan Inventory of Dangerous Pathogens is different from an institute-specific pathogen inventory system, as it is intended to store the information collected from laboratories in the country working with dangerous pathogens in 1 centralized secure location. The Uganda National Council for Science and Technology (UNCST) has coordinated the implementation of the Ugandan national inventory. The inventory was recognized by the WHO JEE as contributing to Uganda's developed capacities regarding biosafety and biosecurity. This article describes the steps in implementing Uganda's National Inventory of Dangerous Pathogens. In addition, it presents a straightforward approach that can be adapted by other countries that aim to enhance their biosecurity capacities.

The Republic of Uganda is one of the first countries to implement a national electronic database that assembles information collected from relevant Ugandan laboratories. This Ugandan Inventory of Dangerous Pathogens is different from an institute-specific pathogen inventory system, as it is intended to store the information collected from laboratories in the country working with dangerous pathogens in a centralized secure location.

Colony-Forming Unit Spreadplate Assay versus Liquid Culture Enrichment-Polymerase Chain Reaction Assay for the Detection of Bacillus Endospores in Soils

A liquid culture enrichment-polymerase chain reaction (E-PCR) assay was investigated as a potential tool to overcome inhibition by chemical component, debris, and background biological impurities in soil that were affecting detection assay performance for soil samples containing Bacillus atrophaeus subsp. globigii (a surrogate for B. anthracis). To evaluate this assay, 9 g of matched sets of three different soil types (loamy sand [sand], sandy loam [loam] and clay) was spiked with 0, ~4.5, 45, 225, 675 and 1350 endospores. One matched set was evaluated using a previously published endospore concentration and colony-forming unit spreadplate (CFU-S) assay and the other matched set was evaluated using an E-PCR assay to investigate differences in limits of detection between the two assays. Data illustrated that detection using the CFU-S assay at the 45-endospore spike level started to become sporadic whereas the E-PCR assay produced repeatable detection at the ~4.5-endospore spike concentration. The E-PCR produced an ~2-log increase in sensitivity and required slightly less time to complete than the CFU-S assay. This study also investigated differences in recovery among pure and blended sand and clay soils and found potential activation of B. anthracis in predominately clay-based soils.

Genetic characteristics of Bacillus anthracis isolated from northwestern China from 1990 to 2016

Anthrax is a global re-emerging zoonotic disease and is an endemic disease in China, especially in rural regions. In this study, the general characteristics of human anthrax outbreaks that occurred in areas of northwestern China over the past decade have been described. Meanwhile, the genetic characteristics of Bacillus anthracis isolated from these areas from 1990 to 2016 were analyzed by means of canonical single-nucleotide polymorphism (canSNP) analysis and multilocus variable-number tandem repeat analysis (MLVA) with 15 markers. Five sublineages/subgroups, namely, A.Br.001/002, A.Br.Vollum, A.Br.Aust94, A.Br.Ames and A.Br.008/009, were detected by using 13 canSNP sites. All of the sublineages were found in Xinjiang province, while one sublineage was found in Shaanxi, two in Gansu, three in Qinghai and four in Inner Mongolia. However, the geographical distribution of the B. anthracis populations exhibited different canSNP characteristics from those of the strains isolated before 1990 in China. In contrast to previous data, the A.Br.Ames subgroup was also observed to be scattered from Inner Mongolia to other provinces. All 106 strains were assigned to 36 MLVA15 genotypes, and 21 of these types were first observed in this study. The strains collected from anthrax outbreaks in recent decade were classified as subgroups A.Br.001/002 and A.Br.Ames and identified as genotypes MLVA15-28, MLVA15-30, MLVA15-31, MLVA15-38, MLVA15-CHN3, and MLVA15-CHN18. By canSNP analysis and MLVA, we found that the diversification of MLVA genotypes and the geographical distribution of B. anthracis populations is gradually becoming balanced across northwestern China. This study also provides preliminary survey results regarding the population diversity of B. anthracis in China, which will help promote the prevention and control of this important disease.

In this study, the general characteristics of human anthrax outbreaks that occurred in northwestern China over the past decade were described. Meanwhile, the genetic characteristics of Bacillus anthracis isolated from these areas from 1990 to 2016 were analyzed with the canSNP and MLVA15 methods. Our results showed a diversity of MLVA genotypes. We also observed gradual balancing of the geographical distribution of B. anthracis population in northwestern China according to the canSNP analysis. In particular, the A.Br.Ames subgroup now seems to be scattered from Inner Mongolia to other provinces, in contrast to the data before 1990. This study also provides preliminary survey results on the population diversity of B. anthracis in China, which will help to promote the prevention and control of this important disease.

Therapeutic Antibodies for Biodefense

Diseases can be caused naturally by biological agents such as bacteria, viruses and toxins (natural risk). However, such biological agents can be intentionally disseminated in the environment by a State (military context) or terrorists to cause diseases in a population or livestock, to destabilize a nation by creating a climate of terror, destabilizing the economy and undermining institutions. Biological agents can be classified according to the severity of illness they cause, its mortality and how easily the agent can be spread. The Centers for Diseases Control and Prevention (CDC) classify biological agents in three categories (A, B and C); Category A consists of the six pathogens most suitable for use as bioweapons (Bacillus anthracis, Yersinia pestis, Francisella tularensis, botulinum neurotoxins, smallpox and viral hemorrhagic fevers). Antibodies represent a perfect biomedical countermeasure as they present both prophylactic and therapeutic properties, act fast and are highly specific to the target. This review focuses on the main biological agents that could be used as bioweapons, the history of biowarfare and antibodies that have been developed to neutralize these agents.

A Standard Method To Inactivate Bacillus anthracis Spores to Sterility via Gamma Irradiation

In 2015, a laboratory of the United States Department of Defense (DoD) inadvertently shipped preparations of gamma-irradiated spores of Bacillus anthracis that contained live spores. In response, a systematic evidence-based method for preparing, concentrating, irradiating, and verifying the inactivation of spore materials was developed. We demonstrate the consistency of spore preparations across multiple biological replicates and show that two different DoD institutions independently obtained comparable dose-inactivation curves for a monodisperse suspension of B. anthracis spores containing 3 × 10¹⁰ CFU. Spore preparations from three different institutions and three strain backgrounds yielded similar decimal reduction (D₁₀) values and irradiation doses required to ensure sterility (D_SAL) to the point at which the probability of detecting a viable spore is 10^-6 Furthermore, spores of a genetically tagged strain of B. anthracis strain Sterne were used to show that high densities of dead spores suppress the recovery of viable spores. Together, we present an integrated method for preparing, irradiating, and verifying the inactivation of spores of B. anthracis for use as standard reagents for testing and evaluating detection and diagnostic devices and techniques.IMPORTANCE The inadvertent shipment by a U.S. Department of Defense (DoD) laboratory of live Bacillus anthracis (anthrax) spores to U.S. and international destinations revealed the need to standardize inactivation methods for materials derived from biological select agents and toxins (BSAT) and for the development of evidence-based methods to prevent the recurrence of such an event. Following a retrospective analysis of the procedures previously employed to generate inactivated B. anthracis spores, a study was commissioned by the DoD to provide data required to support the production of inactivated spores for the biodefense community. The results of this work are presented in this publication, which details the method by which spores can be prepared, irradiated, and tested, such that the chance of finding residual living spores in any given preparation is 1/1,000,000. These irradiated spores are used to test equipment and methods for the detection of agents of biological warfare and bioterrorism.

Effect of Sterilants on Amplification and Detection of Target DNA from Bacillus cereus Spores

To conceal criminal activity of a bioterrorist or agroterrorist, the site of pathogen generation is often treated with sterilants to kill the organisms and remove evidence. As dead organisms cannot be analyzed by culture, this study examined whether DNA from sterilant-treated Bacillus cereus spores was viable for amplification. The spores were exposed to five common sterilants: bleach, Sterilox®, oxidizer foam (L-Gel), a peroxyacid (Actril®), and formaldehyde vapor. The spores were inoculated on typical surfaces found in offices and laboratories to test for environmental effects. It was found that the surface influenced the efficiency of recovery of the organisms. The DNA isolated from the recovered spores was successfully detected using RT-qPCR for all treatments except for formaldehyde, by amplifying the phosphatidylinositol phospholipase C and sphingomyelinase genes. The results demonstrated that evidence from sites treated with sterilants can still provide information on the uncultured organism, using DNA amplification.

Structural and immunochemical relatedness suggests a conserved pathogenicity motif for secondary cell wall polysaccharides in Bacillus anthracis and infection-associated Bacillus cereus

Bacillus anthracis (Ba) and human infection-associated Bacillus cereus (Bc) strains Bc G9241 and Bc 03BB87 have secondary cell wall polysaccharides (SCWPs) comprising an aminoglycosyl trisaccharide repeat: →4)-β-d-ManpNAc-(1→4)-β-d-GlcpNAc-(1→6)-α-d-GlcpNAc-(1→, substituted at GlcNAc residues with both α- and β-Galp. In Bc G9241 and Bc 03BB87, an additional α-Galp is attached to O-3 of ManNAc. Using NMR spectroscopy, mass spectrometry and immunochemical methods, we compared these structures to SCWPs from Bc biovar anthracis strains isolated from great apes displaying “anthrax-like” symptoms in Cameroon (Bc CA) and Côte d’Ivoire (Bc CI). The SCWPs of Bc CA/CI contained the identical HexNAc trisaccharide backbone and Gal modifications found in Ba, together with the α-Gal-(1→3) substitution observed previously at ManNAc residues only in Bc G9241/03BB87. Interestingly, the great ape derived strains displayed a unique α-Gal-(1→3)-α-Gal-(1→3) disaccharide substitution at some ManNAc residues, a modification not found in any previously examined Ba or Bc strain. Immuno-analysis with specific polyclonal anti-Ba SCWP antiserum demonstrated a reactivity hierarchy: high reactivity with SCWPs from Ba 7702 and Ba Sterne 34F2, and Bc G9241 and Bc 03BB87; intermediate reactivity with SCWPs from Bc CI/CA; and low reactivity with the SCWPs from structurally distinct Ba CDC684 (a unique strain producing an SCWP lacking all Gal substitutions) and non-infection-associated Bc ATCC10987 and Bc 14579 SCWPs. Ba-specific monoclonal antibody EAII-6G6-2-3 demonstrated a 10–20 fold reduced reactivity to Bc G9241 and Bc 03BB87 SCWPs compared to Ba 7702/34F2, and low/undetectable reactivity to SCWPs from Bc CI, Bc CA, Ba CDC684, and non-infection-associated Bc strains. Our data indicate that the HexNAc motif is conserved among infection-associated Ba and Bc isolates (regardless of human or great ape origin), and that the number, positions and structures of Gal substitutions confer unique antigenic properties. The conservation of this structural motif could open a new diagnostic route in detection of pathogenic Bc strains.

Forensic Approaches to Detect Possible Agents of Bioterror

Many biological agents have been strategic pathogenic agents throughout history. Some have even changed history as a consequence of early discoveries of their use as weapons of war. Many of these bioagents can be easily isolated from the environment, and some have recently been genetically manipulated to become more pathogenic for biowarfare. However, it is difficult to determine accidental outbreaks of disease from intentional exposures. In this review, we examine how molecular tools have been used in combination with forensic research to resolve cases of unusual outbreaks and trace the source of the biocrime. New technologies are also discussed in terms of their crucial role impacting forensic science. The anthrax event of 2001 serves as an example of the real threat of bioterrorism and the employment of bioagents as weapons against a population. The Amerithrax investigation has given us lessons of the highest resolution possible with new technologies capable of distinguishing isolates at the base-pair level of sensitivity. In addition, we discuss the implications of proper sanitation to avoid waterborne diseases. The use of new methods in forensic science and health-related surveillance will be invaluable in determining the source of any new disease outbreak, and these data will allow for a quick response to any type of public health threat, whether accidental or purposely initiated.

Rapid SNP Detection and Genotyping of Bacterial Pathogens by Pyrosequencing

Bacterial identification and typing are fixtures of microbiology laboratories and are vital aspects of our response mechanisms in the event of foodborne outbreaks and bioterrorist events. Whole genome sequencing (WGS) is leading the way in terms of expanding our ability to identify and characterize bacteria through the identification of subtle differences between genomes (e.g. single nucleotide polymorphisms (SNPs) and insertions/deletions). Modern high-throughput technologies such as pyrosequencing can facilitate the typing of bacteria by generating short-read sequence data of informative regions identified by WGS analyses, at a fraction of the cost of WGS. Thus, pyrosequencing systems remain a valuable asset in the laboratory today. Presented in this chapter are two methods developed in the Amoako laboratory that detail the identification and genotyping of bacterial pathogens. The first targets canonical single nucleotide polymorphisms (canSNPs) of evolutionary importance in Bacillus anthracis, the causative agent of Anthrax. The second assay detects Shiga-toxin (stx) genes, which are associated with virulence in Escherichia coli and Shigella spp., and differentiates the subtypes of stx-1 and stx-2 based on SNP loci. These rapid methods provide end users with important information regarding virulence traits as well as the evolutionary and biogeographic origin of isolates.

Alternative pre-approved and novel therapies for the treatment of anthrax

BACKGROUND

Bacillus anthracis, the causative agent of anthrax, is a spore forming and toxin producing rod-shaped bacterium that is classified as a category A bioterror agent. This pathogenic microbe can be transmitted to both animals and humans. Clinical presentation depends on the route of entry (direct contact, ingestion, injection or aerosolization) with symptoms ranging from isolated skin infections to more severe manifestations such as cardiac or pulmonary shock, meningitis, and death. To date, anthrax is treatable if antibiotics are administered promptly and continued for 60 days. However, if treatment is delayed or administered improperly, the patient's chances of survival are decreased drastically. In addition, antibiotics are ineffective against the harmful anthrax toxins and spores. Therefore, alternative therapeutics are essential. In this review article, we explore and discuss advances that have been made in anthrax therapy with a primary focus on alternative pre-approved and novel antibiotics as well as anti-toxin therapies.

METHODS

A literature search was conducted using the University of Manitoba search engine. Using this search engine allowed access to a greater variety of journals/articles that would have otherwise been restricted for general use. In order to be considered for discussion for this review, all articles must have been published later than 2009.

RESULTS

The alternative pre-approved antibiotics demonstrated high efficacy against B. anthracis both in vitro and in vivo. In addition, the safety profile and clinical pharmacology of these drugs were already known. Compounds that targeted underexploited bacterial processes (DNA replication, RNA synthesis, and cell division) were also very effective in combatting B. anthracis. In addition, these novel compounds prevented bacterial resistance. Targeting B. anthracis virulence, more specifically the anthrax toxins, increased the length of which treatment could be administered.

CONCLUSIONS

Several novel and pre-existing antibiotics, as well as toxin inhibitors, have shown increasing promise. A combination treatment that targets both bacterial growth and toxin production would be ideal and probably necessary for effectively combatting this armed bacterium.

Comparative Microbial Genomics and Forensics

Forensic science concerns the application of scientific techniques to questions of a legal nature and may also be used to address questions of historical importance. Forensic techniques are often used in legal cases that involve crimes against persons or property, and they increasingly may involve cases of bioterrorism, crimes against nature, medical negligence, or tracing the origin of food- and crop-borne disease. Given the rapid advance of genome sequencing and comparative genomics techniques, we ask how these might be used to address cases of a forensic nature, focusing on the use of microbial genome sequence analysis. Such analyses rely on the increasingly large numbers of microbial genomes present in public databases, the ability of individual investigators to rapidly sequence whole microbial genomes, and an increasing depth of understanding of their evolution and function. Suggestions are made as to how comparative microbial genomics might be applied forensically and may represent possibilities for the future development of forensic techniques. A particular emphasis is on the nascent field of genomic epidemiology, which utilizes rapid whole-genome sequencing to identify the source and spread of infectious outbreaks. Also discussed is the application of comparative microbial genomics to the study of historical epidemics and deaths and how the approaches developed may also be applicable to more recent and actionable cases.

Unique Inflammatory Mediators and Specific IgE Levels Distinguish Local from Systemic Reactions after Anthrax Vaccine Adsorbed Vaccination

Although the U.S. National Academy of Sciences concluded that anthrax vaccine adsorbed (AVA) has an adverse event (AE) profile similar to those of other adult vaccines, 30 to 70% of queried AVA vaccinees report AEs. AEs appear to be correlated with certain demographic factors, but the underlying immunologic pathways are poorly understood. We evaluated a cohort of 2,421 AVA vaccinees and found 153 (6.3%) reported an AE. Females were more likely to experience AEs (odds ratio [OR] = 6.0 [95% confidence interval {CI} = 4.2 to 8.7]; P < 0.0001). Individuals 18 to 29 years of age were less likely to report an AE than individuals aged 30 years or older (OR = 0.31 [95% CI = 0.22 to 0.43]; P < 0.0001). No significant effects were observed for African, European, Hispanic, American Indian, or Asian ancestry after correcting for age and sex. Additionally, 103 AEs were large local reactions (LLRs), whereas 53 AEs were systemic reactions (SRs). In a subset of our cohort vaccinated 2 to 12 months prior to plasma sample collection (n = 75), individuals with LLRs (n = 33) had higher protective-antigen (PA)-specific IgE levels than matched, unaffected vaccinated individuals (n = 50; P < 0.01). Anti-PA IgE was not associated with total plasma IgE, hepatitis B-specific IgE, or anti-PA IgG in individuals who reported an AE or in matched, unaffected AVA-vaccinated individuals. IP-10 was also elevated in sera of individuals who developed LLRs (P < 0.05). Individuals reporting SRs had higher levels of systemic inflammation as measured from C-reactive protein (P < 0.01). Thus, LLRs and SRs are mediated by distinct pathways. LLRs are associated with a vaccine-specific IgE response and IP-10, whereas SRs demonstrate increased systemic inflammation without a skewed cytokine profile.

Phylogenetic Characteristics of Anthrax Outbreaks in Liaoning Province, China, 2001-2015

Anthrax is a continuous threat in China, especially in rural regions. In July 2015, an anthrax outbreak occurred in Xifeng County, Liaoning Province. A total of 10 cutaneous anthrax cases were reported, with 210 people under medical observation. In this study, the general characteristics of human anthrax outbreak occurred in Liaoning Province were described, and all cases were caused by butchering and contacting sick animal. Meanwhile, the phylogenetic relationship between outbreak-related isolates/samples of the year 2015 and previous Bacillus anthracis strains was analyzed by means of canonical single nucleotide polymorphisms (canSNP), multiple-locus variable-number tandem repeat analysis (MLVA) with 15 markers and single-nucleotide repeats (SNR) analysis. There are two canSNP subgroups found in Liaoning, A.Br.001/002 and A.Br.Ames, and a total of six MLVA 15 genotypes and five SNR genotypes were observed. The strain collected from anthrax outbreak in Xifeng County in 2015 was classified as A.Br.001/002 subgroup and identified as MLVA15-29 genotype, with same SNR profile (CL10: 17, CL12: 15, CL33: 29, and CL35: 13). So we conclude that the same clone of B.anthracis caused the anthrax outbreak in Xifeng County in 2015, and this clone is different to previous isolates. Strengthening public health education in China is one of the most important measures to prevent and control anthrax.

Animal Models for the Pathogenesis, Treatment, and Prevention of Infection by Bacillus anthracis

This article reviews the characteristics of the major animal models utilized for studies on Bacillus anthracis and highlights their contributions to understanding the pathogenesis and host responses to anthrax and its treatment and prevention. Advantages and drawbacks associated with each model, to include the major models (murine, guinea pig, rabbit, nonhuman primate, and rat), and other less frequently utilized models, are discussed. Although the three principal forms of anthrax are addressed, the main focus of this review is on models for inhalational anthrax. The selection of an animal model for study is often not straightforward and is dependent on the specific aims of the research or test. No single animal species provides complete equivalence to humans; however, each species, when used appropriately, can contribute to a more complete understanding of anthrax and its etiologic agent.

Atmospheric dispersion modelling of bioaerosols that are pathogenic to humans and livestock - A review to inform risk assessment studies

In this review we discuss studies that applied atmospheric dispersion models (ADM) to bioaerosols that are pathogenic to humans and livestock in the context of risk assessment studies. Traditionally, ADMs have been developed to describe the atmospheric transport of chemical pollutants, radioactive matter, dust, and particulate matter. However, they have also enabled researchers to simulate bioaerosol dispersion. To inform risk assessment, the aims of this review were fourfold, namely (1) to describe the most important physical processes related to ADMs and pathogen transport, (2) to discuss studies that focused on the application of ADMs to pathogenic bioaerosols, (3) to discuss emission and inactivation rate parameterisations, and (4) to discuss methods for conversion of concentrations to infection probabilities (concerning quantitative microbial risk assessment). The studies included human, livestock, and industrial sources. Important factors for dispersion included wind speed, atmospheric stability, topographic effects, and deposition. Inactivation was mainly governed by humidity, temperature, and ultraviolet radiation. A majority of the reviewed studies, however, lacked quantitative analyses and application of full quantitative microbial risk assessments (QMRA). Qualitative conclusions based on geographical dispersion maps and threshold doses were encountered frequently. Thus, to improve risk assessment for future outbreaks and releases, we recommended determining well-quantified emission and inactivation rates and applying dosimetry and dose-response models to estimate infection probabilities in the population at risk.

Whole-Genome Sequencing in Microbial Forensic Analysis of Gamma-Irradiated Microbial Materials

Effective microbial forensic analysis of materials used in a potential biological attack requires robust methods of morphological and genetic characterization of the attack materials in order to enable the attribution of the materials to potential sources and to exclude other potential sources. The genetic homogeneity and potential intersample variability of many of the category A to C bioterrorism agents offer a particular challenge to the generation of attributive signatures, potentially requiring whole-genome or proteomic approaches to be utilized. Currently, irradiation of mail is standard practice at several government facilities judged to be at particularly high risk. Thus, initial forensic signatures would need to be recovered from inactivated (nonviable) material. In the study described in this report, we determined the effects of high-dose gamma irradiation on forensic markers of bacterial biothreat agent surrogate organisms with a particular emphasis on the suitability of genomic DNA (gDNA) recovered from such sources as a template for whole-genome analysis. While irradiation of spores and vegetative cells affected the retention of Gram and spore stains and sheared gDNA into small fragments, we found that irradiated material could be utilized to generate accurate whole-genome sequence data on the Illumina and Roche 454 sequencing platforms.

Forensic DNA Analysis of Wheat Flour as Commonly Used in White Powder Cases

In the wake of terrorist attacks using anthrax and ricin, white powder is often encountered in cases of malicious mischief and terrorist threats. Wheat flour is a common white powder encountered in such criminal investigations. We used DNA analysis to investigate wheat flour samples for identification and discrimination as trace evidence. Species identification of commercially available wheat flour was carried out by sequencing a partial region of the ribulose bisphosphate carboxylase large subunit gene (rbcL). Samples were discriminated using short tandem repeat (STR) analysis. The rbcL sequences of all wheat flour samples were identical and showed a high level of similarity to known wheat (Triticum aestivum L.) sequences. Furthermore, flours had characteristic patterns in STR analyses, with specific cultivars showing distinctive patterns. These results suggested that the identification of wheat flour species is possible using rbcL sequencing, and that STR analysis is useful for discriminating between samples.

Beyond the bedside: A review of translational medicine in global health

Translational research is a broad field of medicine with several key phases moving from scientific discovery to bench research and the hospital bedside, followed by evidence-based practice and population-level policy and programming. Understanding these phases is crucial when it comes to preventing and treating illness, especially in global health. Communities around the world struggle with a variety of health problems that are at some times similar and at others quite different. Three major world health issues help to outline the phases of translational research: vaccines, human immunodeficiency virus and acquired immunodeficiency syndrome, and non-communicable diseases. Laboratory research has excelled in many of these areas and is struggling in a few. Where successful therapies have been discovered there are often problems with appropriate use or dissemination to groups in need. Also, many diseases would be better prevented from a population health approach. This review highlights successes and struggles in the arena of global health, from smallpox eradication to the impending epidemic of cardiovascular disease, in an attempt to illustrate of the various phases of translational research.

Two cases of human cutaneous anthrax in Bosnia and Herzegovina, September 2014

Two cases of human cutaneous anthrax were reported in September 2014 in south-western Bosnia and Herzegovina. The two men were involved in slaughtering a cow and handled its Bacillus anthracis-infected meat. Anthrax has been sporadically observed in livestock in Bosnia and Herzegovina, but no confirmed human cases had been reported in the country in the last two decades. Clinicians in the country should be aware that anthrax may occur in humans, arising from exposure to infected animals.

Microbial Forensics☆

Biothreats are a high priority concern for public safety and national security. The field of microbial forensics was developed to analyze evidence associated with biological crimes in which microbes or their toxins are used as weapons. Microbial forensics is the scientific discipline dedicated to analyzing evidence from a bioterrorism act, biocrime, hoax, or inadvertent microorganism/toxin release for attribution purposes. Microbial forensics combines the practices of epidemiology with the characterization of microbial and microbial-related evidence to assist in determining the specific source of the sample, as individualizing as possible, and/or the methods, means, processes and locations involved to determine the identity of the perpetrator(s) of an attack.

Genetic diversity of Bacillus anthracis in Europe: genotyping methods in forensic and epidemiologic investigations

Bacillus anthracis, the etiological agent of anthrax, a zoonosis relatively common throughout the world, can be used as an agent of bioterrorism. In naturally occurring outbreaks and in criminal release of this pathogen, a fast and accurate diagnosis is crucial to an effective response. Microbiological forensics and epidemiologic investigations increasingly rely on molecular markers, such as polymorphisms in DNA sequence, to obtain reliable information regarding the identification or source of a suspicious strain. Over the past decade, significant research efforts have been undertaken to develop genotyping methods with increased power to differentiate B. anthracis strains. A growing number of DNA signatures have been identified and used to survey B. anthracis diversity in nature, leading to rapid advances in our understanding of the global population of this pathogen. This article provides an overview of the different phylogenetic subgroups distributed across the world, with a particular focus on Europe. Updated information on the anthrax situation in Europe is reported. A brief description of some of the work in progress in the work package 5.1 of the AniBioThreat project is also presented, including (1) the development of a robust typing tool based on a suspension array technology and multiplexed single nucleotide polymorphisms scoring and (2) the typing of a collection of DNA from European isolates exchanged between the partners of the project. The know-how acquired will contribute to improving the EU's ability to react rapidly when the identity and real origin of a strain need to be established.

Historical perspective on agroterrorism: lessons learned from 1945 to 2012

This article presents a historical perspective on agroterrorism cases from 1945 until 2012. The threat groups and perpetrators associated with bio- and agroterrorism are clustered into several groups: apocalyptic sects, lone wolves, political groups, and religious groups. We used open-source information, and 4 biological agroterrorism cases are described: (1) in 1952, Mau Mau poisoned cattle in Kenya by using a plant toxin from the African milk bush plant; (2) in 1985, the USDA claimed that Mexican contract workers were involved in deliberately spreading screwworm (Cochliomyia hominivorax) among livestock; (3) in 2000, Palestinian media reported that Israeli settlers released sewer water into Palestinian agricultural fields; and (4) in 2011, a person was sentenced to prison after threatening US and UK livestock with the deliberate spread of foot-and-mouth disease virus. All 4 cases can be assigned to political groups. These cases have not attracted much attention in literature nor in the public media, and the credibility of the sources of information varies. We concluded that agroterrorism has not been a problem during the period studied. Lessons learned from the few cases have generated awareness about the fact that nontypical biological weapons and non-high-risk agents, such as African milk bush, screwworm, and sewer water, have been used by attackers to influence local decision makers. This review will be useful in improving future preparedness planning and developing countermeasures.

Two-step source tracing strategy of Yersinia pestis and its historical epidemiology in a specific region

Source tracing of pathogens is critical for the control and prevention of infectious diseases. Genome sequencing by high throughput technologies is currently feasible and popular, leading to the burst of deciphered bacterial genome sequences. Utilizing the flooding genomic data for source tracing of pathogens in outbreaks is promising, and challenging as well. Here, we employed Yersinia pestis genomes from a plague outbreak at Xinghai county of China in 2009 as an example, to develop a simple two-step strategy for rapid source tracing of the outbreak. The first step was to define the phylogenetic position of the outbreak strains in a whole species tree, and the next step was to provide a detailed relationship across the outbreak strains and their suspected relatives. Through this strategy, we observed that the Xinghai plague outbreak was caused by Y. pestis that circulated in the local plague focus, where the majority of historical plague epidemics in the Qinghai-Tibet Plateau may originate from. The analytical strategy developed here will be of great help in fighting against the outbreaks of emerging infectious diseases, by pinpointing the source of pathogens rapidly with genomic epidemiological data and microbial forensics information.

Sensitive Detection ofBacillus anthracisUsing a Binding Protein Originating from γ-Phage

Detection of biological weapons is a primary concern in force protection, treaty verification, and safeguarding civilian populations against domestic terrorism. One great concern is the detection of Bacillus anthracis, the causative agent of anthrax. Therefore, there is a pressing need to develop novel methods for rapid, simple, and precise detection of B. anthracis. Here, we report that the C-terminal region of gamma-phage lysin protein (PlyG) binds specifically to the cell wall of B. anthracis and the recombinant protein corresponding to this region (positions, 156-233), PlyGB, is available as a bioprobe for detection of B. anthracis. Our detection method, based on a membrane direct blot assay using recombinant PlyGB, was more rapid and sensitive than the gamma-phage test and was simpler and more inexpensive than genetic methods such as PCR, or immunological methods using specific antibodies. Furthermore, its specificity was comparable to the gamma-phage test. PlyGB is applicable in conventional methods instead of antibodies and could be a potent tool for detection of B. anthracis.

Characterization of AmiBA2446, a novel bacteriolytic enzyme active against Bacillus species

There continues to be a need for developing efficient and environmentally friendly treatments for Bacillus anthracis, the causative agent of anthrax. One emerging approach for inactivation of vegetative B. anthracis is the use of bacteriophage endolysins or lytic enzymes encoded by bacterial genomes (autolysins) with highly evolved specificity toward bacterium-specific peptidoglycan cell walls. In this work, we performed in silico analysis of the genome of Bacillus anthracis strain Ames, using a consensus binding domain amino acid sequence as a probe, and identified a novel lytic enzyme that we termed AmiBA2446. This enzyme exists as a homodimer, as determined by size exclusion studies. It possesses N-acetylmuramoyl-l-alanine amidase activity, as determined from liquid chromatography-mass spectrometry (LC-MS) analysis of muropeptides released due to the enzymatic digestion of peptidoglycan. Phylogenetic analysis suggested that AmiBA2446 was an autolysin of bacterial origin. We characterized the effects of enzyme concentration and phase of bacterial growth on bactericidal activity and observed close to a 5-log reduction in the viability of cells of Bacillus cereus 4342, a surrogate for B. anthracis. We further tested the bactericidal activity of AmiBA2446 against various Bacillus species and demonstrated significant activity against B. anthracis and B. cereus strains. We also demonstrated activity against B. anthracis spores after pretreatment with germinants. AmiBA2446 enzyme was also stable in solution, retaining its activity after 4 months of storage at room temperature.

MHC class II and non-MHC class II genes differentially influence humoral immunity to Bacillus anthracis lethal factor and protective antigen

Anthrax Lethal Toxin consists of Protective Antigen (PA) and Lethal Factor (LF), and current vaccination strategies focus on eliciting antibodies to PA. In human vaccination, the response to PA can vary greatly, and the response is often directed toward non-neutralizing epitopes. Variable vaccine responses have been shown to be due in part to genetic differences in individuals, with both MHC class II and other genes playing roles. Here, we investigated the relative contribution of MHC class II versus non-MHC class II genes in the humoral response to PA and LF immunization using three immunized strains of inbred mice: A/J (H-2k at the MHC class II locus), B6 (H-2b), and B6.H2k (H-2k). IgG antibody titers to LF were controlled primarily by the MHC class II locus, whereas IgG titers to PA were strongly influenced by the non-MHC class II genetic background. Conversely, the humoral fine specificity of reactivity to LF appeared to be controlled primarily through non-MHC class II genes, while the specificity of reactivity to PA was more dependent on MHC class II. Common epitopes, reactive in all strains, occurred in both LF and PA responses. These results demonstrate that MHC class II differentially influences humoral immune responses to LF and PA.

Identification of novel and cross-species seroreactive proteins from Bacillus anthracis using a ligation-independent cloning-based, SOS-inducible expression system

The current standard for Bacillus anthracis vaccination is the Anthrax Vaccine Adsorbed (AVA, BioThrax). While effective, the licensed vaccine schedule requires five intramuscular injections in the priming series and yearly boosters to sustain protection. One potential approach to maintain or improve the protection afforded by an anthrax vaccine, but requiring fewer doses, is through the use of purified proteins to enhance an antibody response, which could be used on their own or in combination with the current vaccine. This study describes a novel, high-throughput system to amplify and clone every gene in the B. anthracis pXO1 and pXO2 virulence plasmids. We attempted to express each cloned gene in Escherichia coli, and obtained full-length expression of 57% of the proteins. Expressed proteins were then used to identify immunogens using serum from three different mammalian infection models: Dutch-belted rabbits, BALB/c mice, and rhesus macaque monkeys. Ten proteins were detected by antibodies in all of these models, eight of which have not been identified as immunoreactive in other studies to date. Serum was also collected from humans who had received the AVA vaccine, and similar screens showed that antigens that were detected in the infection models were not present in the serum of vaccinated humans, suggesting that antibodies elicited by the current AVA vaccine do not react with the immunoreactive proteins identified in this study. These results will contribute to the future selection of targets in antigenicity and protection studies as one or more of these proteins may prove to be worthy of inclusion in future vaccine preparations.

Existence of separate domains in lysin PlyG for recognizing Bacillus anthracis spores and vegetative cells

As a potential antimicrobial, the bacteriophage lysin PlyG has been reported to specifically recognize Bacillus anthracis vegetative cells only and to kill B. anthracis vegetative cells and its germinating spores. However, how PlyG interacts with B. anthracis spores remains unclear. Herein, a 60-amino-acid domain in PlyG (residues 106 to 165), located mainly in the previously identified catalytic domain, was found able to specifically recognize B. anthracis spores but not vegetative cells. The exosporium of the spores was found to be the most probable binding target of this domain. This is the first time that a lysin for spore-forming bacteria has been found to have separate domains to recognize spores and vegetative cells, which might help in understanding the coevolution of phages with spore-forming bacteria. Besides providing new biomarkers for developing better assays for identifying B. anthracis spores, the newly found domain may be helpful in developing PlyG as a preventive antibiotic to reduce the threat of anthrax in suspected exposures to B. anthracis spores.

New developments in vaccines, inhibitors of anthrax toxins, and antibiotic therapeutics for Bacillus anthracis

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.

Progress and novel strategies in vaccine development and treatment of anthrax

The lethal anthrax disease is caused by spores of the gram-positive Bacillus anthracis, a member of the cereus group of bacilli. Although the disease is very rare in the Western world, development of anthrax countermeasures gains increasing attention due to the potential use of B. anthracis spores as a bio-terror weapon. Protective antigen (PA), the non-toxic subunit of the bacterial secreted exotoxin, fulfills the role of recognizing a specific receptor and mediating the entry of the toxin into the host target cells. PA elicits a protective immune response and represents the basis for all current anthrax vaccines. Anti-PA neutralizing antibodies are useful correlates for protection and for vaccine efficacy evaluation. Post exposure anti-toxemic and anti-bacteremic prophylactic treatment of anthrax requires prolonged antibiotic administration. Shorter efficient postexposure treatments may require active or passive immunization, in addition to antibiotics. Although anthrax is acknowledged as a toxinogenic disease, additional factors, other than the bacterial toxin, may be involved in the virulence of B. anthracis and may be needed for the long-lasting protection conferred by PA immunization. The search for such novel factors is the focus of several high throughput genomic and proteomic studies that are already leading to identification of novel targets for therapeutics, for vaccine candidates, as well as biomarkers for detection and diagnosis.

Anthrax letters in an open office environment: effects of selected CDC response guidelines on personal exposure and building contamination

In 2001, letters filled with a powder containing anthrax (Bacillus anthracis) spores were delivered by mail to a number of governmental and media locations within the United States. In response, the U.S. Centers for Disease Control and Prevention (CDC) provided guidelines for office personnel who might encounter a letter containing suspicious powder. These guidelines were developed during the crisis and in the absence of experimental data from laboratory or field investigations. An obvious need thus exists for quantitative and scientific verification for validation of these guidelines. This study attempts to address this need, adapting earlier work that used a multiple small office test site to create a model system in an open office test site in a vacated office building in which Bacillus atrophaeus spores (as a simulant for B. anthracis spores) were released by opening a letter. Using SF(6) as a tracer gas, smoke tubes (containing stannic chloride) to visualize airflow, culturable aerosol sampling, and aerosol spectrometry we were able to characterize airflow and unmitigated spore aerosol dissemination within the office test site. Subsequently, two scripted test scenarios were used to reproduce selected portions of the existing CDC response guidelines and a modified version where the contaminated letter opener warned co-workers to evacuate then waited 5 min before doing so himself. By not leaving together with other co-workers, the risk of the letter opener cross-contaminating others was eliminated. The total potential spore aerosol exposure of the letter opener was not affected by remaining still and waiting 5 min to allow co-workers to escape first before leaving the office. Closing office doors and quickly deactivating the heating, ventilation, and air conditioning system significantly reduced spore aerosol concentrations outside the main open office in which they had been released.

MLVA and SNP analysis identified a unique genetic cluster in Bulgarian Bacillus anthracis strains

A collection of 40 Bacillus anthracis strains mostly isolated from soil in Bulgaria between 1960 and 1980 were investigated. All strains were proven to be B. anthracis by culture and amplification of a B. anthracis-specific chromosomal marker. PCR demonstrated that in nine strains both virulence plasmids (pX01+/pX02+) and in four strains only one plasmid (pX02+) were present, whereas the majority of strains (n = 27) lacked both plasmids (pX01-/pX02-). Multi-locus-variable number of tandem repeat-analysis (MLVA) using 15 markers differentiated three genotypes. Comparison with typing data of more than 1,000 different B. anthracis strains revealed that Bulgarian genotypes affiliated with the A1.a cluster and form their own unique cluster different from clusters containing strains isolated in geographical proximity, e.g., Turkey, Georgia, Hungary, Albania or Italy. In addition, a new allele of one marker (vrrC2) was identified. Canonical single nucleotide polymorphisms analysis allocated 31 Bulgarian strains into the A.Br.008/009 and nine strains into the A.Br.WNA group, which is the first description of B. anthracis strains of the A.Br.WNA group on the Eurasian continent.

Bioinformatics for biodefense: challenges and opportunities

The intentional release of traditional or combinatorial bioweapons remains one of the most important challenges that will continue to shape homeland security. The misuse of dual-use and how-to methods and techniques in the fields of molecular, synthetic, and computational biology can lessen the technical barriers for launching attacks, even for small groups or individuals. Bioinformatics is guiding the implementation of several biodefense countermeasures. However, existing algorithms have not effectively translated available pathogen genomic data into standardized diagnostics, rational vaccine development, or broad spectrum therapeutics. Despite its potential, bioinformatics has a limited impact on forensic and intelligence operations. More than 12 biodefense databases and information exchange architectures lack interoperability and a common layer that restricts scalability and the development of biodefense enterprises. Therefore, in order to use next-generation genome sequencing for medical intelligence, forensic operations, biothreat awareness, and mitigation, the attention has to be redirected toward the development of computational biology applications. This article debates some of the challenges that the bioinformatics field confronts in terms of biodefense problems and proposes potential opportunities to use pathogen genomic data. Issues related to the analysis of pathogen genomes and emerging methods including genomic barcoding, active curation, and knowledge management and their impact on intelligence, forensics, and policymaking are discussed.

Genome-wide single nucleotide polymorphism typing method for identification of Bacillus anthracis species and strains among B. cereus group species

As an issue of biosecurity, species-specific genetic markers have been well characterized. However, Bacillus anthracis strain-specific information is currently not sufficient for traceability to identify the origin of the strain. By using genome-wide screening using short read mapping, we identified strain-specific single nucleotide polymorphisms (SNPs) among B. anthracis strains including Japanese isolates, and we further developed a simplified 80-tag SNP typing method for the primary investigation of traceability. These 80-tag SNPs were selected from 2,965 SNPs on the chromosome and the pXO1 and pXO2 plasmids from a total of 19 B. anthracis strains, including the available genome sequences of 17 strains in the GenBank database and 2 Japanese isolates that were sequenced in this study. Phylogenetic analysis based on 80-tag SNP typing showed a higher resolution power to discriminate 12 Japanese isolates rather than the 25 loci identified by multiple-locus variable-number tandem-repeat analysis (MLVA). In addition, the 80-tag PCR testing enabled the discrimination of B. anthracis from other B. cereus group species, helping to identify whether a suspected sample originates from the intentional release of a bioterrorism agent or environmental contamination with a virulent agent. In conclusion, 80-tag SNP typing can be a rapid and sufficient test for the primary investigation of strain origin. Subsequent whole-genome sequencing will reveal apparent strain-specific genetic markers for traceability of strains following an anthrax outbreak.

Targeted proteomics approach to species-level identification of Bacillus thuringiensis spores by AP-MALDI-MS

Anthrax infections progress at a rapid pace, making rapid detection methods of utmost importance. MALDI-MS proteomics methods focused on Bacillus anthracis detection have targeted chromosomally encoded proteins, which are highly conserved between closely related species, hindering species identification. Presented here is an AP-MALDI-MS method targeting plasmid-borne proteins from Bacillus spores for species-level identification. A bioinformatics analysis revealed that 60.3% and 75.4% of tryptic peptides from plasmid-borne proteins of B. anthracis and B. thuringiensis were species-specific, respectively. Reported here is a method in which plasmid-borne delta-endotoxins were extracted directly from B. thuringiensis spores in 100 mM KOH. The pH was then adjusted to 8 and a 5-min trypsin digestion was performed on the extracted proteins. The resulting tryptic peptides were analyzed by AP-MALDI-MS/MS, which produced a definitive identification the B. thuringiensis species-specific Cry1Ab protein with a MASCOT score of 278 and expect value of 7.5 x 10(-23). This method has demonstrated the detection and identification of B. thuringiensis spores at the species level following a 5-min trypsin digestion. The challenges in applying a similar approach to the detection of plasmid-borne protein toxins from B. anthracis are also discussed.