Search Results (233)

Background noise and intensive sample preparation frequently compromise the field screening of Bacillus anthracis. Addressing these analytical bottlenecks, we constructed a giant magnetoresistive (GMR) biosensor incorporating geometrically tailored trapezoidal magnetic flux concentrators (MFCs). 3D finite element magnetic simulations directed the MFC topology to mitigate edge saturation, reconciling central magnetic gain with spatial uniformity. The resulting platform demonstrated a 100-fold sensitivity improvement over recent electrochemical methods, achieving a limit of detection (LOD) of 10 CFU/mL in standard buffers, with the entire testing process completed within 40 min. Direct target quantification remained viable in heterogeneous matrices—muddy water, whole milk, and apple cider—circumventing tedious pretreatment. This geometric and magnetic optimization yields a pragmatic sensing architecture tailored for on-site biodefense monitoring. Full article

Anthrax is a zoonotic infectious disease characterized by high lethality and transmissibility. Its spores are highly stable and can persist in the environment for long periods. Furthermore, the overuse or improper use of antibiotics may contribute to bacterial resistance, complicating anthrax treatment. Phages can efficiently target and lyse Bacillus anthracis (B. anthracis), significantly reducing pathogen contamination and transmission risks in soil, water, and other environmental media. Compared to traditional chemical disinfectants and antibiotics, phages enable precise pathogen elimination while minimizing ecological disruption. In this study, two phages infecting B. anthracis, vB_BanM-JC307 (JC307) and vB_BanS-YL5 (YL5), were isolated and characterized. Both phages belong to the class Caudoviricetes. Genome sequencing revealed that JC307 and YL5 have sequence lengths of 148,323 bp and 74,568 bp, respectively. Phylogenetic analysis indicates that JC307 is located in the same evolutionary branch as the Nachito phage of the Herelleviridae family, while YL5, although grouped with the Basilisk-like phages, forms an independent branch. As these two phages have been observed to exhibit lytic activity against all nine tested strains of B. anthracis, they could serve as auxiliary tools for pathogen diagnosis and assist in ecological management of anthrax-contaminated areas. Full article

Anthrax is one of the most significant zoonotic diseases in Albania due to its endemic presence in livestock, the potential for occupational exposure, and human cases. Although the implementation of risk-based livestock immunization, animal movement restrictions, and appropriate carcass disposal, the efficacy of targeted management remains limited in certain outbreaks due to insufficient enforcement of these measures. Their efficacy is specifically diminished by insufficient disinfection, the absence of grazing bans in contaminated pastures, and the absence of designated burial sites for the safe disposal of dead animals. District-level data on animal anthrax control programs were collected and analyzed for the period 2021–2025. In addition, a retrospective analysis of national datasets covering the same period was conducted using data from the national surveillance system, alongside a review of the relevant scientific and grey literature and aggregated program and routine surveillance data. Analysis showed that anthrax affected 149 animals in 97 farms, and the average number of animals per infected farm declined from 1.70 to 1.08, indicating a slight reduction within-farm outbreak. Hotspots for human anthrax were aligned with the animal cases and persisted particularly in the southern districts. The peak of outbreaks was in 2023, primarily driven by cattle (n = 32) and sheep (n = 24). Equine cases appeared only in 2024, with small clusters of 3 cases in both 2024 and 2025. Caprine cases remained consistently low throughout the period. Nevertheless, the number of outbreaks and within-herd cases are decreasing due to more rapid identification and response. Targeted surveillance on animal outbreaks provides critical insights into disease spread and links among affected farms in Albania. Therefore, One Health genomic surveillance and antibiotic susceptibility testing of Bacillus anthracis isolates are essential for understanding its epidemiology, transmission routes, and for tracing the sources of infection across humans, animals, and the environment. Full article

A thorough understanding of the functions of virulence regulators in Bacillus anthracis evolution and host adaptation, particularly the systematic host responses they trigger, requires an efficient infection model capable of resolving subtle mechanisms. This study constructed a high-resolution host immune response decoder based on Galleria mellonella to analyze the specific response profiles elicited by different virulence regulators in a capsule-deficient background. By integrating transcriptomic, histopathological, and bacterial colonization analyses, the research delineated distinct host immune stress profiles regulated by AtxA and PlcR. The results showed that the AtxA-deficient strain failed to elicit significant host responses; wild-type infection activated broad systemic immune recognition pathways, while the PlcR-activated strain induced a unique response profile characterized by perturbations in oxidative stress pathways. Its enhanced virulence was associated with the expression of downstream hydrolases and occurred without strong systemic immune activation. This work successfully advanced the G. mellonella model from a phenotypic screener to a mechanistic resolver, providing a new methodological framework for distinguishing B. anthracis virulence regulatory mechanisms at the host response level. This approach not only deciphers pathogen-specific immune signatures but also offers a practical platform for rapid anti-virulence compound screening and guides the design of targeted validation in mammalian systems, thereby accelerating therapeutic strategy development against anthrax. Full article

The Bacillus cereus group (B. cereus group) comprises several closely related species that share high genetic similarity but display markedly different phenotypic traits and pathogenic potential. Reliable and rapid discrimination at the species level remains challenging using conventional microbiological and molecular methods. In this study, Fourier Transform Infrared (FTIR) spectroscopy was evaluated as a rapid phenotypic approach to differentiate seven members of the Bacillus cereus sensu stricto (B. cereus s.s.), Bacillus anthracis (B. anthracis), Bacillus thuringiensis (B. thuringensis), Bacillus mycoides (B. mycoides), Bacillus toyonensis (B. toyonensis), Bacillus wiedmannii (B. wiedmannii) and Bacillus weihenstephanensis (B. weihenstephanensis). A collection of 190 isolates previously characterized by whole genome sequencing was analyzed using the IR Biotyper system. Spectral data were processed through multivariate analyses, including principal component analysis and linear discriminant analysis, following a hierarchical classification strategy. FTIR spectroscopy enabled clear discrimination of B. anthracis from other members of the B. cereus group and allowed the separation of several additional species based on distinct spectral signatures. A further discrimination step permitted differentiation between B. cereus sensu stricto and B. thuringiensis, with minimal overlap. These findings demonstrate that FTIR spectroscopy represents a promising and rapid tool for species-level discrimination within the B. cereus group. While the results should be considered preliminary for species represented by a limited number of isolates, this approach shows strong potential as a complementary method to molecular techniques in routine diagnostics in food safety and veterinary microbiology. Full article

Anthrax, caused by Bacillus anthracis, remains a significant zoonotic disease across the globe disproportionately affecting rural populations reliant on livestock farming. Despite the availability of vaccines for humans and animals, and preventive measures, anthrax outbreaks continue to occur due to convergence of inadequate animal husbandry practices, socioeconomic vulnerabilities, and cultural traditions. This study aimed to identify and quantitatively synthesize the key exposure-related behavioral risk factors for human anthrax infection while contextualizing socio-demographic and cultural determinants through narrative review. A systematic review and meta-analysis were performed in accordance with PRISMA guidelines. Using a random-effects model, risk estimates were pooled exclusively for exposure-related behavioral pathways that are mechanistically linked to anthrax transmission, while socio-demographic and cultural variables were summarized narratively due to heterogeneity in study design, variable definition, and limited cross-study comparability. A total of 20 studies were included, primarily from Africa, Asia, and Europe. The meta-analysis identified a consistent set of high-risk exposure pathways, including contact with raw meat from infected animals (OR = 5.79, 95% CI: 4.04–8.31), skinning (OR = 5.64, 95% CI: 3.73–8.52), butchering (OR = 6.54, 95% CI: 3.26–13.09), slaughtering or presence during slaughter (OR = 5.16, 95% CI: 2.54–10.49), and handling of carcasses or animal by-products (OR = 4.13, 95% CI: 2.88–5.92). Socio-demographic and cultural factors, including religious norms and demographic characteristics, were consistently identified as contextual modifiers of anthrax risk across studies but were not quantitatively pooled because of methodological and definitional heterogeneity. While heterogeneity varied by risk factor, it remained generally low to moderate, supporting the consistency of findings across diverse settings. Our findings emphasize that direct exposure-related behaviors represent the dominant and consistent transmission pathways for human anthrax across endemic settings. Effective prevention strategies should prioritize improved livestock management, enhanced biosecurity systems, community education on safe animal handling practices, particularly the handling of moribund livestock or dead animals of unknown origin, and strengthened veterinary services. Future research should prioritize region-specific interventions and conduct longitudinal studies to assess the effectiveness of anthrax risk reduction efforts. Full article

Bacillus anthracis displays susceptibility to penicillin despite harboring a β-lactamase gene, a phenotype governed by the anti-sigma factor RsiP. While RsiP represses σ^P-dependent β-lactamase expression, its broader roles in physiology and virulence remain unclear. This study aimed to define the global regulatory functions of RsiP beyond antibiotic resistance. Deletion of rsiP significantly upregulated the nprR gene, which is an important quorum-sensing (QS) system regulator and enhanced protease secretion. The ΔrsiP mutant caused higher mortality in cellular and Galleria mellonella models and triggered elevated inflammatory cytokines (IL-6, IL-1β, TNF-α, MIP-2) in macrophages models. Surprisingly, in DBA/2 mice models, ΔrsiP was attenuated, with increased host survival and reduced bacterial loads. Competitive indices (CI) confirmed fitness defects in mice (spleen CI = 0.39; liver CI = 0.42). These defects were not due to altered oxidative stress tolerance but were attributed to impaired macrophage internalization of ΔrsiP spores, reducing early colonization. Our findings indicate that RsiP not only modulates β-lactam resistance but also influences extracellular protease activity and host adaptation. Full article

Bacillus anthracis has three main virulence factors: an extracellular capsule and two binary toxins (lethal toxin—consists of a lethal factor and a protective antigen, and edema toxin—consists of an edema factor and a protective antigen). In the Russian Federation, the epidemiological situation regarding anthrax infection remains unfavorable. In the late stages of an anthrax infection, antibiotic therapy becomes ineffective and the patient dies within 24 h as a large amount of lethal toxin accumulates in the patient’s blood. Antibodies capable of neutralising lethal toxin (LT) can be an effective treatment for these patients. The objective of the study was to construct a chimeric monoclonal antibody targeting the protective antigen of the LT and to elucidate its mechanism of toxin neutralization. In this work, a chimeric monoclonal antibody (xi1E10) directed against the protective antigen was successfully produced. Both in vitro and in vivo experiments demonstrated the capacity of xi1E10 to neutralize lethal toxin. Confocal microscopy revealed that xi1E10 effectively suppresses the formation of a functional pore, thereby blocking the translocation of the lethal factor into the cytosol. These findings indicate that the monoclonal antibody xi1E10 represents a promising candidate for the development of a therapeutic drug. Full article

This study presents an ultra-sensitive dual-core photonic crystal fiber-based surface plasmon resonance (PCF-SPR) sensor for the detection of waterborne pathogens through refractive index (RI) variation. The proposed sensor integrates a bimetallic coating of silver and titanium dioxide (Ag–TiO₂). Silver ensures sharp plasmonic resonance, and TiO₂ enhances chemical stability and coupling efficiency. This dual-core configuration allows for increased interaction between the core-guided modes and the plasmonic interface. As a result, the sensor’s sensitivity improves significantly. The sensor can accurately detect analytes with an RI value of 1.28 to 1.43. It demonstrates a maximum wavelength sensitivity (WS) of 107,000 nm/RIU, an amplitude sensitivity (AS) of 2209.21 RIU⁻¹, a wavelength resolution of 9.35 × 10⁻⁷ RIU, and a figure of merit (FOM) of about 520. These results support the sensor’s ability to identify the presence of different pathogenic contaminants, such as E. coli, Vibrio cholerae, and Bacillus anthracis, based on their unique RI properties. This optimized design, high resolution, and potential for real-time detection enable this sensor to be a promising solution for environmental monitoring applications. Full article

Antimicrobial resistance (AMR) in bacteria is a critical global health threat, yet the impact of environmental stressors such as aerosolization on resistance remains unclear. We previously showed that aerosolization can induce antibiotic resistance in Escherichia coli MG1655, a gram-negative pathogen simulant. Here, we investigated Bacillus globigii, a surrogate for the gram-positive pathogen Bacillus anthracis, to assess how aerosolization affects bacterial survival and antibiotic resistance. B. globigii vegetative cells and spores were aerosolized under varying conditions and durations (5, 10, 15, 30, and 45 min) into a sterile, airtight chamber and collected using the wetted wall cyclone (WWC) system. Samples were analyzed via antibiotic susceptibility testing, culture-based assay, and quantitative polymerase chain reaction (qPCR). Vegetative cells exhibited the lowest culturability after 5 and 30 min aerosolization, while spores showed reduced culturability at 15–45 min. Both vegetative cells and spores displayed lowest antibiotic susceptibility profiles after 15 min of aerosolization. Our findings suggest that aerosolization duration and bacterial state (vegetative vs. spores) can influence bacterial survival and development of antibiotic resistance. Understanding these dynamics is essential for designing strategies to mitigate the airborne spread of antibiotic-resistant bacteria. Full article

Bacillus anthracis is the etiological agent of the zoonotic disease anthrax. The pathogen has colonized many regions of all inhabited continents. Increasing evidence points to a strong contribution of anthropogenic activities (trade) in this almost global spread. This article contributes further genomic data from 21 B. anthracis strains, including 19 isolated in Germany, aiming to support and detail the human role in anthrax dispersal. The newly sequenced genomes belong to the B. anthracis lineage predominant in China. This lineage is remarkable because of its phylogenetic structure. A polytomy with nine branches radiating from a central node was identified by whole-genome single-nucleotide polymorphism (wgSNP) analysis. Strains from Germany populate two among the nine branches. Detailed analysis of the polytomy indicates that it most likely emerged in China. We propose that the polytomy is the result of the import of contaminated animal products in a limited spatiotemporal frame, followed by the distribution of these products to different locations within China, where new B. anthracis lineages then became independently established. Currently available data point to Bengal as a likely geographic source of the original contamination, and the history of trade exchanges between Bengal and China agrees with the early fifteenth century as a likely time period. The subsequent exports to Germany would have occurred during the 19th century according to German trade history. Notably, Germany has been experiencing localized anthrax outbreaks from this trade heritage up into the 21st century. Full article

The Bacillus anthracis pXO1 plasmid, encoding ~143 proteins, presents a compact model for exploring protein function and evolutionary patterns using protein language models. Due to the organism’s slow evolutionary rate, its limited amino acid variation enhances detection of physiologically relevant patterns in plasmid protein composition. In this study, we applied embedding-based analyses and machine learning methods to characterize pXO1 protein modules across diverse B. anthracis lineages. We generated protein sequence embeddings, constructed phylogenies, and compared plasmid content with whole genome variation. While whole genome and plasmid-based phylogenies diverge, the composition of proteins encoded along the pXO1 plasmid revealed lineage specific structure. Association rule mining combined with decision tree classification produced plasmid-encoded targets for assessing anthrax sublineage, which yielded functionally redundant protein modules that reflected geographic and phylogenetic patterns. A conserved DNA replication module exhibited both shared and B. anthracis lineage specific features. These results show that pXO1 plasmid protein modules contain biologically meaningful and evolutionarily informative signatures, exemplifying their value in phylogeographic characterizations of bacterial pathogens. This framework can be extended to study additional virulence plasmids across Bacillus and other environmental pathogens using scalable protein language model tools. Full article

The Centers for Disease Control and Prevention (CDC) classifies Bacillus anthracis as one of the most dangerous pathogens that may affect public health and national security. Due to its importance as a potential biological weapon, this bacteria has been classified in the highest category A, together with such pathogens as variola virus or botulinum neurotoxin. Characteristic features of this pathogen that increase its military importance are the ease of its cultivation, transport, and storage and its ability to create survival forms that are extremely resistant to environmental conditions. However, beyond bioterrorism, B. anthracis is also a naturally occurring pathogen. Anthrax outbreaks occur in livestock and wildlife, particularly in spore-contaminated regions of Africa, Asia, and North America. Spores persist for decades, leading to recurrent infections and zoonotic transmission through direct contact, inhalation, or consumption of contaminated meat. This work presents a new electrochemical method for detecting and quantifying B. anthracis in spore form using a selective immune reaction. The developed method is based on the thiol-modified electrodes that constitute the sensing element of the electrochemical system. Tests with the B. anthracis spore suspension showed that the detection limit for this pathogen is as low as 10³ CFU/mL. Furthermore, it was possible to quantify the analyte with a sensitivity of 11 mV/log (CFU/mL). Due to several features, such as low unit cost, portability, and minimal apparatus demands, this method can be easily implemented in field analyzers for this pathogen and provides an alternative to currently used techniques and devices. Full article

Protein toxins are biologically active polypeptides produced by a variety of organisms, including bacteria, plants, fungi, and animals. These molecules exert potent and specific toxic effects on target cells and are primarily associated with pathogenicity and defense mechanisms of the organisms. In the past few decades, significant progress has been made in understanding their structure, mechanisms of action, and regulation. Among these, bacterial protein toxins have emerged as valuable tools particularly in the development of targeted therapies. A notable example is Botulinum toxin, originally known for its neurotoxic effects, which was approved as a therapeutic agent in 1989 for strabismus treatment, paving way for repurposing bacterial toxins for clinical use. This review provides an overview of the different classes of bacterial toxin-based therapeutics, with a particular focus on Pseudomonas exotoxin A (PE) from Pseudomonas aeruginosa and anthrax toxin from Bacillus anthracis. The modular architecture and potent cytotoxicity of these A-B type toxins have enabled their successful adaptation into targeted cancer therapies. The clinical approval of the PE-based immunotoxin, moxetumomab pasudotox, for the treatment of hairy cell leukemia, underscores the potential of this strategy. This review also discusses current challenges and outlines future directions for the advancement of bacterial toxin-based therapeutics. Full article

Anthrax remains a serious bioterrorism threat for which new and thermostable vaccines are needed. We previously demonstrated that immunization of rabbits with multiple-antigenic-peptide (MAP) vaccines elicit antibody (Ab) against the loop-neutralizing-determinant (LND), a cryptic linear neutralizing epitope in the 2β2-2β3 loop of protective antigen (PA) from Bacillus anthracis (B. anthracis), which mediates the complete protection of rabbits from inhalation spore challenge with B. anthracis Ames strain. Importantly, LND-specific Ab is not significantly elicited with PA-based vaccines. In the current study, we sought to identify a second unique neutralizing epitope which would also not overlap with the neutralizing specificities elicited by PA-based vaccines, and which could be combined with an LND vaccine as a prototype bivalent vaccine for anthrax. We evaluated linear peptide sequences in the α2-α3 helices of domain 3 of lethal factor (LF) in the form of virus-like particle (VLP) vaccines. Immunogenicity studies confirmed the presence of a 20-mer peptide sequence that is capable of eliciting protective levels of neutralizing Ab following two immunizations of rabbits using human-use adjuvants, and lyophilization of the VLPs did not diminish their immunogenicity. To our knowledge, this is the first demonstration that immunization with linear peptide sequences from LF can elicit protective levels of neutralizing Ab in vivo. Full article