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Pathogens (Basel, Switzerland) Jun 2022Anthrax has been feared for its high mortality in animals and humans for centuries. The etiologic agent is considered a potentially devastating bioweapon, and since...
Anthrax has been feared for its high mortality in animals and humans for centuries. The etiologic agent is considered a potentially devastating bioweapon, and since 1876-when Robert Koch demonstrated that Bacillus anthracis caused anthrax-it has been considered the sole cause of the disease. Anthrax is, however, a toxin-mediated disease. The toxins edema toxin and lethal toxin are formed from protein components encoded for by the pXO1 virulence plasmid present in pathogenic strains. However, other members of the group, to which belongs, have recently been shown to harbor the pXO1 plasmid and produce anthrax toxins. Infection with these group organisms produces a disease clinically similar to anthrax. This suggests that anthrax should be defined by the exotoxins encoded for by the pXO1 plasmid rather than the bacterial species it has historically been associated with, and that the definition of anthrax should be expanded to include disease caused by any member of the group containing the toxin-producing pXO1 plasmid or anthrax toxin genes specifically.
PubMed: 35745544
DOI: 10.3390/pathogens11060690 -
Clinical Infectious Diseases : An... Oct 2022The neurological sequelae of Bacillus anthracis infection include a rapidly progressive fulminant meningoencephalitis frequently associated with intracranial hemorrhage,... (Review)
Review
The neurological sequelae of Bacillus anthracis infection include a rapidly progressive fulminant meningoencephalitis frequently associated with intracranial hemorrhage, including subarachnoid and intracerebral hemorrhage. Higher mortality than other forms of bacterial meningitis suggests that antimicrobials and cardiopulmonary support alone may be insufficient and that strategies targeting the hemorrhage might improve outcomes. In this review, we describe the toxic role of intracranial hemorrhage in anthrax meningoencephalitis. We first examine the high incidence of intracranial hemorrhage in patients with anthrax meningoencephalitis. We then review common diseases that present with intracranial hemorrhage, including aneurysmal subarachnoid hemorrhage and spontaneous intracerebral hemorrhage, postulating applicability of established and potential neurointensive treatments to the multimodal management of hemorrhagic anthrax meningoencephalitis. Finally, we examine the therapeutic potential of minocycline, an antimicrobial that is effective against B. anthracis and that has been shown in preclinical studies to have neuroprotective properties, which thus might be repurposed for this historically fatal disease.
Topics: Anthrax; Bacillus anthracis; Cerebral Hemorrhage; Humans; Meningoencephalitis; Minocycline
PubMed: 36251558
DOI: 10.1093/cid/ciac521 -
Pathogens (Basel, Switzerland) Oct 2022Bacillus anthracis, present as a very durable endospore in soil, causes zoonotic illness which is mainly associated with herbivores and domestic animals. Human cases are... (Review)
Review
Bacillus anthracis, present as a very durable endospore in soil, causes zoonotic illness which is mainly associated with herbivores and domestic animals. Human cases are scarce and often involve populations close to infected livestock. If anthrax is no longer of public health concern in developed countries, B. anthracis is one of the top-tier biological weapon agents. It is classified by the CDC as a category A agent. Since 1994, emerging strains of Bacillus cereus have been associated with anthrax-like disease in mammals. Some clinical strains of B. cereus harbor anthrax-like plasmid genes (pXO1 and pXO2) associated with non-human primate and human infections, with the same clinical presentation of inhalation anthrax and mortality rates. Although currently restricted to certain limited areas of circulation, the emergence of these new strains of B. cereus extends the list of potential agents possibly usable for bioterrorism or as a biological weapon. It is therefore important to improve our knowledge of the phylogeny within the B. cereus sensu lato group to better understand the origin of these strains. We can then more efficiently monitor the emergence of new strains to better control the risk of infection and limit potentially malicious uses.
PubMed: 36297243
DOI: 10.3390/pathogens11101186 -
Microbiology Spectrum Nov 2019As obligate anaerobes, clostridial pathogens depend on their metabolically dormant, oxygen-tolerant spore form to transmit disease. However, the molecular mechanisms by... (Review)
Review
As obligate anaerobes, clostridial pathogens depend on their metabolically dormant, oxygen-tolerant spore form to transmit disease. However, the molecular mechanisms by which those spores germinate to initiate infection and then form new spores to transmit infection remain poorly understood. While sporulation and germination have been well characterized in and , striking differences in the regulation of these processes have been observed between the bacilli and the clostridia, with even some conserved proteins exhibiting differences in their requirements and functions. Here, we review our current understanding of how clostridial pathogens, specifically , , and , induce sporulation in response to environmental cues, assemble resistant spores, and germinate metabolically dormant spores in response to environmental cues. We also discuss the direct relationship between toxin production and spore formation in these pathogens.
Topics: Animals; Clostridium; Clostridium Infections; Humans; Spores, Bacterial
PubMed: 31858953
DOI: 10.1128/microbiolspec.GPP3-0017-2018 -
Virulence Dec 2021is an obligate pathogen and a causative agent of anthrax. Its major virulence factors are plasmid-coded; however, recent studies have revealed chromosome-encoded...
is an obligate pathogen and a causative agent of anthrax. Its major virulence factors are plasmid-coded; however, recent studies have revealed chromosome-encoded virulence factors, indicating that the current understanding of its virulence mechanism is elusive and needs further investigation. In this study, we established a silkworm ( infection model of . We showed that silkworms were killed by Sterne and cured of the infection when administered with antibiotics. We quantitatively determined the lethal dose of the bacteria that kills 50% larvae and effective doses of antibiotics that cure 50% infected larvae. Furthermore, we demonstrated that mutants with disruption in virulence genes such as , and had attenuated silkworm-killing ability and reduced colonization in silkworm hemolymph. The silkworm infection model established in this study can be utilized in large-scale infection experiments to identify novel virulence determinants and develop novel therapeutic options against infections.
Topics: Animals; Anthrax; Anti-Bacterial Agents; Bacillus anthracis; Bombyx; Disease Models, Animal; Virulence; Virulence Factors
PubMed: 34490836
DOI: 10.1080/21505594.2021.1965830 -
Vavilovskii Zhurnal Genetiki I Selektsii Oct 2022Bacillus anthracis is the anthrax causative agent. For its epidemiology, it is important not only to identify the etiological agent but also to determine the patterns of...
Bacillus anthracis is the anthrax causative agent. For its epidemiology, it is important not only to identify the etiological agent but also to determine the patterns of its evolution and spread. Modern methods of molecular biology make it possible to detect a number of genetic markers suitable for indicating and differentiating the strains of B. anthracis, including the loci arranged as variable number tandem repeats (VNTRs) and SNPs, one nucleotide-sized differences in the DNA sequence of the loci being compared. The objective of the present study was to examine the effectiveness of SNP analysis and PCR amplif ication of VNTR loci combined with the high-resolution amplicon melting analysis for identif ication and differentiation of the anthrax agent strains. In the study, seven strains of B. anthracis obtained from soil samples and animal carcasses were investigated using vaccine strain STI-1 as a reference. For molecular genetic characterization of these bacteria, analysis of 12 SNPs and variability analysis of eight VNTR loci were carried out. To detect the differences between the strains, their PCR product melting points were measured in the presence of the EvaGreen (Sintol, Russia) intercalating dye. For SNP detection, a PCR assay with double TaqMan probes was applied. It was found that the studied virulent strains, except for B. anthracis No. 1 and 3, could not be attributed to any phylogenetic subgroup of the anthrax agents. The proposed method made it possible to differentiate four out of the seven investigated strains. Strains No. 5-7 had identical SNP and HRM prof iles and, as a result, formed a single cluster. Our investigation has conf irmed that the proposed method can be successfully used for preliminary analysis of an epizootic situation in the case of anthrax.
PubMed: 36313827
DOI: 10.18699/VJGB-22-68 -
Microorganisms Nov 2020Anthrax is a highly resilient and deadly disease caused by the spore-forming bacterial pathogen . The bacterium presents a complex and dynamic composition of its cell... (Review)
Review
Anthrax is a highly resilient and deadly disease caused by the spore-forming bacterial pathogen . The bacterium presents a complex and dynamic composition of its cell envelope, which changes in response to developmental and environmental conditions and host-dependent signals. Because of their easy to access extracellular locations, cell envelope components represent interesting targets for the identification and development of novel therapeutic and vaccine strategies. This review will focus on the novel insights regarding the composition, physiological role, and clinical relevance of cell envelope components.
PubMed: 33255913
DOI: 10.3390/microorganisms8121864