Repurposing FDA-approved disulfiram for targeted inhibition of diphtheria toxin and the binary protein toxins of Clostridium botulinum and Bacillus anthracis.

Many bacteria act pathogenic by the release of AB-type protein toxins that efficiently enter human or animal cells and act as enzymes in their cytosol. This leads to disturbed cell functions and the clinical symptoms characteristic for the individual toxin. Therefore, molecules that directly target and neutralize these toxins provide promising novel therapeutic options. Here, we found that the FDA-approved drug disulfiram (DSF), used for decades to treat alcohol abuse, protects cells from intoxication with diphtheria toxin (DT) from Corynebacterium diphtheria, the causative agent of diphtheria, lethal toxin (LT) from Bacillus anthracis, which contributes to anthrax, and C2 enterotoxin from Clostridium botulinum when applied in concentrations lower than those found in plasma of patients receiving standard DSF treatment for alcoholism (up to 20 µM). Moreover, this inhibitory effect is increased by copper, a known enhancer of DSF activity. LT and C2 are binary toxins, consisting of two non-linked proteins, an enzyme (A) and a separate binding/transport (B) subunit. To act cytotoxic, their proteolytically activated B subunits PA63 and C2IIa, respectively, form barrel-shaped heptamers that bind to their cellular receptors and form complexes with their respective A subunits LF and C2I. The toxin complexes are internalized via receptor-mediated endocytosis and in acidified endosomes, PA63 and C2IIa form pores in endosomal membranes, which facilitate translocation of LF and C2I into the cytosol, where they act cytotoxic. In DT, A and B subunits are located within one protein, but DT also forms pores in endosomes that facilitate translocation of the A subunit. If cell binding, membrane translocation, or substrate modification is inhibited, cells are protected from intoxication. Our results implicate that DSF neither affects cellular binding nor the catalytic activity of the investigated toxins to a relevant extend, but interferes with the toxin pore-mediated translocation of the A subunits of DT, LT and C2 toxin, as demonstrated by membrane-translocation assays and toxin pore conductivity experiments in the presence or absence of DSF. Since toxin translocation across intracellular membranes represents a central step during cellular uptake of many bacterial toxins, DSF might neutralize a broad spectrum of medically relevant toxins.

Risk perceptions and preventive preparedness toward anthrax re-emergence within the lens of one health in Northcentral Nigeria.

Anthrax has re-emerged in domestic ruminants in Nigeria with public health concerns. This study assessed stakeholders' perceptions and preventive preparedness toward further resurgence and spread at the human-animal-environment interface. A questionnaire-based cross-sectional study was conducted in Nigeria. Descriptive and analytical statistical analyses were performed at 95% confidence levels. All the 384 recruited stakeholders responded. The majority (96.2%) of animal health practitioners (AHPs) and 56.7% of pastoralists were aware of the recent anthrax re-emergence in Nigeria (p < 0.001). Noteworthy, 88.5% of the AHPs and 32.2% of pastoralists mentioned that anthrax has an environmental component in its transmission to humans and animals. From the environmental perspective, 87.7% of AHPs and 24.0% of pastoralists significantly perceived that soil and aerosol contamination with anthrax spores are highly plausible explanation routes for its re-emergence. Extreme weather events (high rainfall, flooding, winds, and drought) (p = 0.001); grazing of livestock on pastures grown on contaminated soil (p < 0.001), transboundary movement and trade of animals (p = 0.001); introduction of new animals into the herds without quarantine (p = 0.001); and bioterrorism (p < 0.001) were more likely to influence the re-emergence and spread of anthrax. To tackle gaps in knowledge and risk perceptions, and address the socio-economic and anthropogenic drivers, cooperation and collaborations through the lens of the One Health approach are needed. The partnership will promote an integrated disease surveillance system from planning to implementation for the realization of elimination or reduction of the burden of anthrax and other zoonoses in Nigeria and contribute to achieving food safety, food security, and public and ecosystem health.

Anthrax in Humans, Animals, and the Environment and the One Health Strategies for Anthrax Control.

Anthrax is a notorious disease of public health importance caused by Bacillus anthracis. The causative agent can also be used as a biological weapon. Spores of these bacteria can sustain extreme environmental conditions and remain viable in soil for decades. Domestic and wild ruminants are highly susceptible to this pathogen, which usually presents as a peracute to acute disease. In humans, cutaneous anthrax is frequent but pulmonary and enteric anthrax are more serious. Humans, animals, and the environment are all involved, making anthrax a perfect target for a One Health approach. The environment plays a key role in disease transmission. At a time when the One Health concept is not mere slogans, collaborative efforts of medical professionals, veterinarians, and environmental scientists will be valuable for the prevention and control of this disease. In this review, we discussed the transmission dynamics of anthrax in the environment, animals, and humans, as well as One Health strategies to control and prevent anthrax.

Comprehensive Spatial-Temporal and Risk Factor Insights for Optimizing Livestock Anthrax Vaccination Strategies in Karnataka, India.

Anthrax, a zoonotic disease affecting both livestock and humans globally, is caused by Bacillus anthracis. The objectives of this study were the following: (1) to identify environmental risk factors for anthrax and use this information to develop an improved predictive risk map, and (2) to estimate spatial variation in basic reproduction number (Ro) and herd immunity threshold at the village level, which can be used to optimize vaccination policies within high-risk regions. Based on the anthrax incidences from 2000-2023 and vaccine administration figures between 2008 and 2022 in Karnataka, this study depicted spatiotemporal pattern analysis to derive a risk map employing machine learning algorithms and estimate Ro and herd immunity threshold for better vaccination coverage. Risk factors considered were key meteorological, remote sensing, soil, and geographical parameters. Spatial autocorrelation and SaTScan analysis revealed the presence of hotspots and clusters predominantly in the southern, central, and uppermost northern districts of Karnataka and temporal cluster distribution between June and September. Factors significantly associated with anthrax were air temperature, surface pressure, land surface temperature (LST), enhanced vegetation index (EVI), potential evapotranspiration (PET), soil temperature, soil moisture, pH, available potassium, sulphur, and boron, elevation, and proximity to waterbodies and waterways. Ensemble technique with random forest and classification tree models were used to improve the prediction accuracy of anthrax. High-risk areas are expected in villages in the southern, central, and extreme northern districts of Karnataka. The estimated Ro revealed 11 high-risk districts with Ro > 1.50 and respective herd immunity thresholds ranging from 11.24% to 55.47%, and the assessment of vaccination coverage at the 70%, 80%, and 90% vaccine efficacy levels, all serving for need-based strategic vaccine allocation. A comparison analysis of vaccinations administered and vaccination coverage estimated in this study is used to illustrate difference in the supply and vaccine force. The findings from the present study may support in planning preventive interventions, resource allocation, especially of vaccines, and other control strategies against anthrax across Karnataka, specifically focusing on predicted high-risk regions.

Alpha-1 antitrypsin inhibits Clostridium botulinum C2 toxin, Corynebacterium diphtheriae diphtheria toxin and B. anthracis fusion toxin.

The bacterium Clostridium botulinum, well-known for producing botulinum neurotoxins, which cause the severe paralytic illness known as botulism, produces C2 toxin, a binary AB-toxin with ADP-ribosyltranferase activity. C2 toxin possesses two separate protein components, an enzymatically active A-component C2I and the binding and translocation B-component C2II. After proteolytic activation of C2II to C2IIa, the heptameric structure binds C2I and is taken up via receptor-mediated endocytosis into the target cells. Due to acidification of endosomes, the C2IIa/C2I complex undergoes conformational changes and consequently C2IIa forms a pore into the endosomal membrane and C2I can translocate into the cytoplasm, where it ADP-ribosylates G-actin, a key component of the cytoskeleton. This modification disrupts the actin cytoskeleton, resulting in the collapse of cytoskeleton and ultimately cell death. Here, we show that the serine-protease inhibitor α1-antitrypsin (α1AT) which we identified previously from a hemofiltrate library screen for PT from Bordetella pertussis is a multitoxin inhibitor. α1AT inhibits intoxication of cells with C2 toxin via inhibition of binding to cells and inhibition of enzyme activity of C2I. Moreover, diphtheria toxin and an anthrax fusion toxin are inhibited by α1AT. Since α1AT is commercially available as a drug for treatment of the α1AT deficiency, it could be repurposed for treatment of toxin-mediated diseases.

Pan-genome analysis reveals novel chromosomal markers for multiplex PCR-based specific detection of Bacillus anthracis.

BACKGROUND: Bacillus anthracis is a highly pathogenic bacterium that can cause lethal infection in animals and humans, making it a significant concern as a pathogen and biological agent. Consequently, accurate diagnosis of B. anthracis is critically important for public health. However, the identification of specific marker genes encoded in the B. anthracis chromosome is challenging due to the genetic similarity it shares with B. cereus and B. thuringiensis. METHODS: The complete genomes of B. anthracis, B. cereus, B. thuringiensis, and B. weihenstephanensis were de novo annotated with Prokka, and these annotations were used by Roary to produce the pan-genome. B. anthracis exclusive genes were identified by Perl script, and their specificity was examined by nucleotide BLAST search. A local BLAST alignment was performed to confirm the presence of the identified genes across various B. anthracis strains. Multiplex polymerase chain reactions (PCR) were established based on the identified genes. RESULT: The distribution of genes among 151 whole-genome sequences exhibited three distinct major patterns, depending on the bacterial species and strains. Further comparative analysis between the three groups uncovered thirty chromosome-encoded genes exclusively present in B. anthracis strains. Of these, twenty were found in known lambda prophage regions, and ten were in previously undefined region of the chromosome. We established three distinct multiplex PCRs for the specific detection of B. anthracis by utilizing three of the identified genes, BA1698, BA5354, and BA5361. CONCLUSION: The study identified thirty chromosome-encoded genes specific to B. anthracis, encompassing previously described genes in known lambda prophage regions and nine newly discovered genes from an undefined gene region to the best of our knowledge. Three multiplex PCR assays offer an accurate and reliable alternative method for detecting B. anthracis. Furthermore, these genetic markers have value in anthrax vaccine development, and understanding the pathogenicity of B. anthracis.

Evaluation of the Epidemic Situation of Anthrax in Armenia Over the Last Decade.

INTRODUCTION: Anthrax is a World Organisation for Animal Health (WOAH)-listed disease that must be reported upon confirmation based on the Terrestrial Animal Health Code. Anthrax poses a serious health issue for unvaccinated livestock, is a threat to humans through interaction with contaminated livestock and animal products and is endemic in many areas throughout the world, including the Transcaucasian Region. Despite several control and eradication efforts that have been implemented by the government of the Republic of Armenia (RA), sporadic cases of anthrax are still reported. We sought to understand the epidemic situation of anthrax in RA during the last 10 years (2012-2023) based on analysis of outbreaks and reported cases in cattle and humans. METHODS: We collected and evaluated officially reported data from human and animal cases, such as time, location, animal species, disease intensity and spread radius. The data and various parameters were mapped using ArcGIS to prepare a viable risk assessment. RESULTS: Based on the officially available data and reports, there have been 80 human cases and 55 animal cases of anthrax confirmed in RA from 2012 to 2023. We also identified the presence of anthrax spores in soil and environmental samples near animal burial sites in RA in 2015-2017 through polymerase chain reaction (PCR) testing. Upon comparing the human and animal cases by frequency and intensity, the human cases are directly proportional to the animal husbandry practices performed in RA. CONCLUSION: The detection of the anthrax pathogen at the burial sites highlights the continued threat in these areas. Thus, it is imperative to secure and monitor any areas that have been used for anthrax burial and limit the movement of animals in these areas. In the future, legislation should be updated to prioritise incineration of anthrax-infected carcasses instead of burial to limit further exposure to animals and humans.

Omadacycline is active in vitro and in vivo against ciprofloxacin-resistant Bacillus anthracis.

Bacillus anthracis, the causative agent of anthrax, is among the most likely bacterial pathogens to be used in a biological attack. Inhalation anthrax is a serious, life-threatening form of infection, and the mortality from acute inhaled anthrax can approach 100% if not treated early and aggressively. Food and Drug Administration-approved antibiotics indicated for post-exposure prophylaxis (PEP) or treatment of anthrax are limited. This study assessed the in vitro activity and in vivo efficacy of omadacycline and comparators against clinical isolates of B. anthracis, including a ciprofloxacin-resistant isolate. Minimum inhibitory concentrations (MICs) of omadacycline, ciprofloxacin, and doxycycline were determined against animal and human clinical isolates of B. anthracis, including the ciprofloxacin-resistant Ames strain BACr4-2. Mice were challenged with aerosolized BACr4-2 spores, and survival was monitored for 28 days post-challenge. Treatment was initiated 24 h after aerosol challenge and administered for 14 days. Omadacycline demonstrated in vitro activity against 53 B. anthracis isolates with an MIC range of ≤0.008-0.25 µg/mL, and an MIC50/MIC90 of 0.015/0.03 µg/mL. Consistent with this, omadacycline demonstrated in vivo efficacy in a PEP mouse model of inhalation anthrax caused by the Ames BACr4-2 ciprofloxacin-resistant B. anthracis isolate. Omadacycline treatment significantly increased survival compared with the vehicle control group and the ciprofloxacin treatment group. As antibiotic resistance rates continue to rise worldwide, omadacycline may offer an alternative PEP or treatment option against inhalation anthrax, including anthrax caused by antibiotic-resistant B. anthracis.

Jean-Nicolas Marjolin (1780-1850): An ulcer, an anthrax, and a rose.

Jean-Nicolas Marjolin was a 19th century French anatomist and surgeon. Although not strictly speaking a pivotal figure in history of medicine, he deserves to be known for at least three reasons. He (more or less accurately) described a type of ulcer which is nowadays referred to as Marjolin's ulcer (1828); he had the privilege of operating on the world-famous Charles-Maurice de Talleyrand-Périgord for an anthrax (1838); and a rose has been named after him since 1860.

Implication of Capillary Morphogenesis Gene 2 (CMG2) in the Disease Progression and Peritoneal Metastasis of Pancreatic Cancer.

Capillary morphogenesis gene 2 (CMG2) mediates cell-matrix interactions to facilitate cell adhesion and migration. CMG2 has been implicated in the disease progression of breast cancer, prostate cancer and gastric cancer. The present study aims to determine the role of CMG2 in the disease progression and peritoneal metastasis of pancreatic cancer. Pancreatic tumour samples were collected from Peking University Cancer Hospital. CMG2 expression was determined using quantitative PCR. After the creation of knockdown and overexpression of CMG2 in pancreatic cancer cells, the effect of CMG2 on several cell functions and adhesion to the peritoneum was examined. Potential pathways regulated by CMG2 were found via proteomics analysis and drug tests. CMG2 was upregulated in pancreatic cancer tissues and associated with a poor prognosis. CMG2 was increased in metastatic lesions and those primary tumours with distant metastases. CMG2 promotes cell-cell, cell-matrix and cell-hyaluronic acid adhesion, which may be mediated by epidermal growth factor receptor (EGFR) and focal adhesion kinase (FAK) pathway activation.

New Insights into the Phylogeny of the A.Br.161 ("A.Br.Heroin") Clade of Bacillus anthracis.

Bacillus anthracis is a rare but highly dangerous zoonotic bacterial pathogen. At the beginning of this century, a new manifestation of the disease, injectional anthrax, emerged as a result of recreational heroin consumption involving contaminated drugs. The organisms associated with this 13-year-lasting outbreak event in European drug consumers were all grouped into the canonical single-nucleotide polymorphism (canSNP) clade A-branch (A.Br.) 161 of B. anthracis. Related clade A.Br.161 strains of B. anthracis not associated with heroin consumption have also been identified from different countries, mostly in Asia. Because of inadvertent spread by anthropogenic activities, other strains of this A.Br.161 lineage were, however, isolated from several countries. Thus, without additional isolates from this clade, its origin of evolution or its autochthonous region remains obscure. Here, we genomically characterized six new A.Br.161 group isolates, some of which were from Iran, with others likely historically introduced into Germany. All the chromosomes of these isolates could be grouped into a distinct sub-clade within the A.Br.161 clade. This sub-clade is separated from the main A.Br.161 lineage by a single SNP. We have developed this SNP into a PCR assay facilitating the future attribution of strains to this group.

Knowledge, attitude and practice related to anthrax among livestock farmers in West Kazakhstan.

BACKGROUND: Anthrax is the most prioritized zoonotic disease in Kazakhstan due to its threatening potential to the public health and agricultural sector. Sporadic anthrax outbreaks are being reported annually among human and livestock populations throughout the country, with the highest frequency occurring in West Kazakhstan. METHODS: A cross-sectional study was conducted using a survey-based face-to-face interview. From January to May 2022, 489 randomly selected participants were surveyed in 6 districts of the Baiterek province in West Kazakhstan oblast to evaluate the knowledge, attitude and practice (KAP) regarding anthrax among community members. This is the first KAP study conducted relating to outbreaks of anthrax in Kazakhstan. RESULTS: In this study, most participants (74%) surveyed were males, and 40% of respondents had a secondary level education. Overall, 91% of the community respondents were engaged in agriculture and livestock rearing. Among these community members, cattle rearing was the most common (67%) occupation compared to other livestock species. Additionally, over a 50% of the population studied had no knowledge about the zoonotic nature of the disease, and about 82% and 87% of respondents were unaware of any animal and human anthrax symptoms, respectively. About 70% of the respondents were interested in vaccinating their livestock against anthrax. Individuals aged 45-54 displayed notably higher animal vaccination rates (45%; 95% CI: 38.4-52.0; p < 0.025) compared to those aged 25-34 and 65-74. Respondents residing in the Beles district (20%; 95% CI: 17.1-24.7; p < 0.005) exhibited a significantly higher level of awareness concerning the fatality of anthrax in contrast to participants from Bolashak. Roughly 61% of respondents held the belief that anthrax is a lethal disease. An overwhelming majority of the survey participants (99%) affirmed their non-participation in the slaughter of infected animals. CONCLUSION: The findings of this study indicate that KAP among community members relating to anthrax is low and requires swift implementation of education programmes in building awareness of anthrax under the One Health approach, especially in anthrax prone regions.

Unveiling the global reach of African anthrax research: A bibliometric study.

Anthrax is a zoonotic bacterial disease caused by Bacillus anthracis. It poses significant threat to humans through contact with infected animals or their by-products. Concerns arise from its long-lasting spore viability and lethality, fuelling its biowarfare potential. Recent anthrax outbreaks across multiple African nations prompted this bibliometric study. The aim of the study was to assess the contributions of African countries, institutions, authors, research funding, and collaborations, while identifying research trends and gaps. We conducted an extensive bibliometric analysis of anthrax-related research publications in Africa from 1923 to 2023, utilizing the Scopus database and VOSviewer. The study covered 364 publications from 32 African countries, accumulating 5,636 citations at an average of 15.5 citations per article, with research articles comprising 88.5% of the corpus. The publication growth rate from 1923 to 2023 was modest at 8.3%, indicating gradual advancement. Notably, there was a significant surge in publications between 2011 and 2023, accounting for 73.1% of total publications. The African research contributions, were categorized into five thematic focuses: ecological dynamics and host interactions, human-livestock anthrax interface, molecular insights into bacterial activity and treatment strategies, collaborative approaches for zoonotic disease prevention, and antibody response and vaccination strategies. Leading institutional contributors included the University of Pretoria and the University of KwaZulu-Natal. Collaborations extended globally to 35 non-African countries, with significant involvement from the United States, United Kingdom, and Germany. Strong African partnerships, especially between Kenya, Nigeria, and South Africa, emerged. The top 10 cited papers explored diverse aspects, including disease impact on wildlife and innovative control strategies, underscoring the importance of multidisciplinary approaches. South Africa played a prominent role, contributing 95 publications and securing funding from various sources, including the National Research Foundation. Collaborations with global institutions highlighted its commitment. This study unveils the dynamic landscape of anthrax research in Africa, emphasizing the pivotal role of collaboration, multidisciplinary One Health approaches, and global partnerships in enhancing research outcomes. Ongoing research and practical solutions for human and animal health remain imperative.

A genome-based investigation of the Priestia species isolated from anthrax endemic regions in Kruger National Park.

Priestia is a genus that was renamed from the genus Bacillus based on the conserved signature indels (CSIs) in protein sequences that separate Priestia species from Bacillus, with the latter only including species closely related to B. subtilis and B. cereus. Diagnosis of anthrax, a zoonotic disease, is implicated by tripartite anthrax virulence genes (lef, pagA, and cya) and poly-γ-D-glutamic acid capsular genes cap-ABCDE of Bacillus anthracis. Due to the amplification of anthrax virulence genes in Priestia isolates, the search for homologous anthrax virulence genes within the Priestia genomes (n = 9) isolated from animal blood smears was embarked upon through whole genome sequencing. In silico taxonomic identification of the isolates was conducted using genome taxonomy database (GTDB), average nucleotide identity (ANI), and multi-locus sequence typing (MLST), which identified the genomes as P. aryabhattai (n = 5), P. endophytica (n = 2) and P. megaterium (n = 2). A pan-genome analysis was further conducted on the Priestia genomes, including the screening of virulence, antibiotic resistance genes and mobile genetic elements on the sequenced genomes. The oligoribonuclease NrnB protein sequences showed that Priestia spp. possess a unique CSI that is absent in other Bacillus species. Furthermore, the CSI in P. endophytica is unique from other Priestia spp. Pan-genomic analysis indicates that P. endophytica clusters separately from P. aryabhattai and P. megaterium. In silico BLASTn genome analysis using the SYBR primers, Taqman probes and primers that target the chromosomal marker (Ba-1), protective antigen (pagA), and lethal factor (lef) on B. anthracis, showed partial binding to Priestia regions encoding for hypothetical proteins, pyridoxine biosynthesis, hydrolase, and inhibitory proteins. The antibiotic resistance genes (ARG) profile of Priestia spp. showed that the genomes contained no more than two ARGs. This included genes conferring resistance to rifamycin and fosfomycin on P. endophytica, as well as clindamycin on P. aryabhattai and P. megaterium. Priestia genomes lacked B. anthracis plasmids and consisted of plasmid replicon types with unknown functions. Furthermore, the amplification of Priestia strains may result in false positives when qPCR is used to detect the virulence genes of B. anthracis in soil, blood smears, and/or environmental samples.

Polyelectrolyte-coated liposomes microfluidically assembled in one-step for enhancing cell endocytosis and in-vivo immune responses.

To enhance the cellular uptake of liposomes, we prepared conventional liposomes with targeting molecules and surface-charged liposomes and evaluated their potential as nano-carriers and vaccine adjuvants by comparing their endocytosis efficiencies using immune cells. Surface-charged liposomes were synthesized via a one-step microfluidic method, which provided a novel, simple, fast, and highly reproducible method for preparing liposomes. Flow cytometry revealed that cationic polyelectrolyte-coated liposomes exhibited higher endocytosis efficiencies (of up to a factor of 100) in A774A.1 cells and JAWs II cells compared with uncoated liposomes or those coated with anionic polyelectrolytes. Positively charged liposomes exhibited some cytotoxicity at quaternary-chitosan coating concentrations higher than 6 mg/mL; however, significantly lower cytotoxicities (by a factor of almost ten) were obtained by protein mixing. Furthermore, BALB/c mice vaccinated with a mixture of Anthrax vaccine adsorbed (AVA) and quaternary chitosan-coated liposomes showed faster and stronger anti-PA IgG inductions compared to those vaccinated with AVA alone, with titers positively correlating with the amount of cationic liposome used. This finding clearly reveals that quaternary chitosan-coated liposomes act as both nano-carriers and vaccine adjuvants that significantly enhance in-vivo immune responses to vaccines with low immunogenicities.

c-di-AMP accumulation impairs toxin expression of Bacillus anthracis by down-regulating potassium importers.

The Gram-positive bacterium Bacillus anthracis is the causative agent of anthrax and a bioterrorism threat worldwide. As a crucial second messenger in many bacterial species, cyclic di-AMP (c-di-AMP) modulates various key processes for bacterial homeostasis and pathogenesis. Overaccumulation of c-di-AMP alters cellular growth and reduces anthrax toxin expression as well as virulence in Bacillus anthracis by unresolved underlying mechanisms. In this report, we discovered that c-di-AMP binds to a series of receptors involved in potassium uptake in B. anthracis. By analyzing Kdp and Ktr mutants for osmotic stress, gene expression, and anthrax toxin expression, we also showed that c-di-AMP inhibits Kdp operon expression through binding to the KdpD and ydaO riboswitch; up-regulating intracellular potassium promotes anthrax toxin expression in c-di-AMP accumulated B. anthracis. Decreased anthrax toxin expression at high c-di-AMP occurs through the inhibition of potassium uptake. Understanding the molecular basis of how potassium uptake affects anthrax toxin has the potential to provide new insight into the control of B. anthracis.IMPORTANCEThe bacterial second messenger cyclic di-AMP (c-di-AMP) is a conserved global regulator of potassium homeostasis. How c-di-AMP regulates bacterial virulence is unknown. With this study, we provide a link between potassium uptake and anthrax toxin expression in Bacillus anthracis. c-di-AMP accumulation might inhibit anthrax toxin expression by suppressing potassium uptake.

Upper Limb Compartment Syndrome-An Extremely Rare Life-Threatening Complication of Cutaneous Anthrax.

(1) Background: Cutaneous anthrax is a disease caused by a Gram-positive bacillus, spore-forming Bacillus anthracis (BA). Cutaneous anthrax accounts for 95% of all anthrax cases, with mortality between 10-40% in untreated forms. The most feared complication, which can be life-threatening and is rarely encountered and described in the literature, is compartment syndrome. (2) Methods: We report a series of six cases of cutaneous anthrax from the same endemic area. In two of the cases, the disease was complicated by compartment syndrome. The systematic review was conducted according to systematic review guidelines, and the PubMed, Google Scholar, and Web of Science databases were searched for publications from 1 January 2008 to 31 December 2023. The keywords used were: "cutaneous anthrax" and "compartment syndrome by cutaneous anthrax". (3) Results: For compartment syndrome, emergency surgical intervention for decompression was required, along with another three surgeries, with hospitalization between 21 and 23 days. In the systematic review, among the 37 articles, 29 did not contain cases focusing on compartment syndrome of the thoracic limb in cutaneous anthrax. The results were included in a Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flow diagram. (4) Conclusions: Early recognition of the characteristic cutaneous lesions and compartment syndrome with early initiation of antibiotics and urgent surgical treatment is the lifesaving solution.

Anthrax Vaccination, Gulf War Illness, and Human Leukocyte Antigen (HLA).

We report on a highly significant, positive association between anthrax vaccination and occurrence of Gulf War Illness (GWI) in 111 Gulf War veterans (42 with GWI and 69 controls). GWI was diagnosed in 47.1% of vaccinated veterans but only in 17.2% of non-vaccinated veterans (Pearson χ2 = 7.08, p = 0.008; odds ratio = 3.947; relative risk = 2.617), with 1.6x higher GWI symptom severity in vaccinated veterans (p = 0.007, F-test in analysis of covariance). Next, we tested the hypothesis that the susceptibility to GWI following anthrax vaccination could be due to inability to make antibodies against the anthrax protective antigen (PA), the key protein contained in the vaccine. Since the first step in initiating antibody production would be the binding of PA peptide fragments (typically 15-amino acid long [15-mer]) to peptide-binding motifs of human leukocyte antigen (HLA) Class II molecules, we assessed the binding-motif affinities of such HLA specific molecules to all linear 15-mer peptide fragments of the anthrax PA. We identified a total of 58 HLA Class II alleles carried by the veterans in our sample and found that, of those, 18 (31%) were present in the vaccinated group that did not develop GWI but were absent from the vaccinated group who developed GWI. Remarkably, in silico analyses revealed very high binding affinities of peptide-binding motifs of those 18 HLA alleles with fragments of anthrax vaccine PA, leading to the successful production of anti-PA antibodies. Conversely, the absence of these protective HLA alleles points to a reduced ability to develop antibodies against PA, thus resulting in harmful PA persistence and development of GWI.

Lysins as a powerful alternative to combat Bacillus anthracis.

This review gathers all, to the best of our current knowledge, known lysins, mainly bacteriophage-derived, that have demonstrated activity against Bacillus anthracis strains. B. anthracis is a spore-forming, toxin-producing bacteria, naturally dwelling in soil. It is best known as a potential biowarfare threat, an etiological agent of anthrax, and a severe zoonotic disease. Anthrax can be treated with antibiotics (ciprofloxacin, penicillin, doxycycline); however, their administration may take up even to 60 days, and different factors can compromise their effectiveness. Bacterial viruses, bacteriophages (phages), are natural enemies of bacteria and use their lytic enzymes, endolysins (lysins), to specifically kill bacterial cells. Harnessing the potential of lysins to combat bacterial infections holds promise for diminishing antibiotic usage and, consequently, addressing the escalating antibiotic resistance in bacteria. In this context, we list the lysins with the activity against B. anthracis, providing a summary of their lytic properties in vitro and the outcomes observed in animal models. Bacillus cereus strain ATCC 4342/RSVF1, a surrogate for B. anthracis, was also included as a target bacteria. KEY POINTS: • More than a dozen different B. anthracis lysins have been identified and studied. • They fall into three blocks regarding their amino acid sequence similarity and most of them are amidases. • Lysins could be used in treating B. anthracis infections.

Associations of community knowledge, perceptions, and practices related to zoonotic disease with sociodemographic factors in and around Chiro Town, Eastern Ethiopia: a cross-sectional study.

BACKGROUND: Zoonoses are infectious diseases that are transmitted from animals to humans. Studying the knowledge, perceptions and practices of communities related to zoonoses and the associated risk factors is crucial for effective control and prevention. This study aimed to assess the knowledge, perceptions, and practices of respondents on zoonoses and the associated risk factors in and around Chiro town, Ethiopia. Zoonotic diseases, such as rabies, anthrax, bovine tuberculosis, and brucellosis, pose a direct threat to health and livelihoods in the communities where they occur. These diseases emerge due to a combination of human-animal interactions, migration, and contact with wildlife and their respective parasites and vectors. Hence, recognizing residents' perceptions, knowledge, and practices is crucial for effectively minimizing risks. METHODS: A cross-sectional study was conducted from January 2020 to July 2021 in and around Chiro town using a pretested close-ended questionnaire. A total of 350 respondents were selected using simple random sampling methods. The questionnaire included information on the sociodemographic status of the respondents and questions concerning the knowledge, perceptions, and practices of the participants regarding the selected zoonotic diseases. The associations of knowledge, perceptions, and practices related to zoonoses with zoonotic risk factors were analysed using chi-square tests. RESULTS: The study revealed that 82.9% of the respondents had knowledge of bovine tuberculosis, followed by knowledge of rabies (80%), knowledge of anthrax (45.1%), and knowledge of brucellosis (24.3%). Males had greater knowledge of bovine tuberculosis (84.8%), followed by rabies (79.8%) and anthrax (48.6%), while females had greater knowledge of brucellosis (23.6%). The most cited source of information was radio (68%). Most respondents mentioned the outbreaks of rabies (62.5%), bovine tuberculosis (53.2%), anthrax (35.6%), and brucellosis (15.7%). Respondents with higher educational levels and urban residents had more knowledge of zoonoses. More than 75% of respondents had a good perception of the transmission of zoonotic disease from animals, and the practice of consuming raw milk or raw/undercooked meat and sharing the same house with animals was high. CONCLUSION: The majority of respondents reported that they had knowledge of bovine tuberculosis and rabies, but lower knowledge and perceptions were reported for anthrax and brucellosis. These findings illustrate the need for collaboration among animal, human and environmental health offices in one health approach to prevent and control zoonotic disease.