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Journal of Applied Microbiology Aug 2015The goal of this work was to determine conditions under which external application of a spore germination-specific lytic enzyme (GSLE) can increase the germination...
AIMS
The goal of this work was to determine conditions under which external application of a spore germination-specific lytic enzyme (GSLE) can increase the germination efficiency of spore populations.
METHODS AND RESULTS
The Bacillus anthracis GSLE SleB was applied to native and coat-disrupted B. anthracis and Bacillus subtilis spores. SleB was inactive on native spores but was able to trigger rapid germination of coat-disrupted spores. Using spores lacking their GSLEs or their germinant receptors to model poorly germinating spores, SleB application was able to increase colony-forming efficiency 100-fold for native spores and >1000-fold for coat-disrupted spores. SleB effects on GSLE-deficient spores were greater than on germinant receptor-deficient spores.
CONCLUSIONS
SleB treatment can increase spore germination efficiency. The greater effect of SleB on coat-disrupted spores is presumably due to the greater access afforded to the cortex. However, SleB apparently gained access to the cortex of native spores after they responded to nutrients and completed stage I of germination, which may result in the disruption of coat structure.
SIGNIFICANCE AND IMPACT OF THE STUDY
Treatment of spore populations with a GSLE can increase germination efficiency. Such a treatment might be utilized to increase the rapid activation of industrial spore-based products.
Topics: Bacillus anthracis; Bacillus subtilis; Bacterial Proteins; Spores, Bacterial
PubMed: 25963559
DOI: 10.1111/jam.12839 -
Journal of Bacteriology Apr 2020Cyclic di-AMP (c-di-AMP) is a recently identified bacterial second messenger that regulates biological processes. In this study, we found that inactivation of two...
Cyclic di-AMP (c-di-AMP) is a recently identified bacterial second messenger that regulates biological processes. In this study, we found that inactivation of two c-di-AMP phosphodiesterases (PDEs), GdpP and PgpH, resulted in accumulation of 3.8-fold higher c-di-AMP levels than in the parental strain Sterne in and inhibited bacterial growth. Moreover, excess c-di-AMP accumulation decreased bacterial toxin expression, increased sensitivity to osmotic stress and detergent, and attenuated virulence in both C57BL/6J and A/J mice. Complementation of the PDE mutant with a plasmid carrying or in from a Pspac promoter restored bacterial growth, virulence factor expression, and resistance to detergent. Our results indicate that c-di-AMP is a pleiotropic signaling molecule in that is important for host-pathogen interaction. Anthrax is an ancient and deadly disease caused by the spore-forming bacterial pathogen Vegetative cells of this species produce anthrax toxin proteins and S-layer components during infection of mammalian hosts. So far, how the expression of these virulence factors is regulated remains largely unknown. Our results suggest that excess elevated c-di-AMP levels inhibit bacterial growth and reduce expression of S-layer components and anthracis toxins as well as reduce virulence in a mouse model of disease. These results indicate that c-di-AMP signaling plays crucial roles in biology and disease.
Topics: Animals; Anthrax; Bacillus anthracis; Bacterial Proteins; Cyclic AMP; Female; Gene Expression Regulation, Bacterial; Humans; Male; Mice; Mice, Inbred C57BL; Virulence
PubMed: 32071095
DOI: 10.1128/JB.00653-19 -
BMC Microbiology Sep 2018Anthrax, the zoonotic disease caused by the gram-positive bacterium Bacillus anthracis, is nowadays rare in northern parts of Europe including Finland and Scandinavia....
BACKGROUND
Anthrax, the zoonotic disease caused by the gram-positive bacterium Bacillus anthracis, is nowadays rare in northern parts of Europe including Finland and Scandinavia. Only two minor outbreaks of anthrax in 1988 and in 2004 and one sporadic infection in 2008 have been detected in animals in Finland since the 1970's. Here, we report on two Finnish B. anthracis strains that were isolated from spleen and liver of a diseased calf related to the outbreak in 1988 (strain HKI4363/88) and from a local scrotum and testicle infection of a bull in 2008 (strain BA2968). These infections occurred in two rural Finnish regions, i.e., Ostrobothnia in western Finland and Päijänne Tavastia in southern Finland, respectively.
RESULTS
The isolates were genetically characterized by PCR-based methods such as multilocus variable number of tandem repeat analysis (MLVA) and whole genome-sequence analysis (WGS). Phylogenetic comparison of the two strains HKI4363/88 and BA2968 by chromosomal single nucleotide polymorphism (SNP) analysis grouped these organisms within their relatives of the minor canonical A-branch canSNP-group A.Br.003/004 (A.Br.V770) or canonical B-branch B.Br.001/002, respectively. Strain HKI4363/88 clustered relatively closely with other members of the A.Br.003/004 lineage from Europe, South Africa, and South America. In contrast, strain BA2968 clearly constituted a new sublineage within B.Br.001/002 with its closest relative being HYO01 from South Korea.
CONCLUSIONS
Our results suggest that Finland harbors both unique (autochthonous) and more widely distributed, common clades of B. anthracis. We suspect that members of the common clades such as strains HKI4363/88 have been introduced only recently by anthropogenic activities involving importation of contaminated animal products. On the other hand, autochthonous strains such as isolate BA2968 probably have an older history of their introduction into Finland as evidenced by a high number of single nucleotide variant sites in their genomes.
Topics: Animals; Anthrax; Bacillus anthracis; Cattle; Cattle Diseases; Finland; Genome, Bacterial; Genotype; Phylogeny; Polymorphism, Single Nucleotide
PubMed: 30176810
DOI: 10.1186/s12866-018-1250-4 -
Viruses Jan 2022is a potent biowarfare agent, able to be highly lethal. The bacteria dwell in the soil of certain regions, as natural flora. Bacteriophages or their lytic enzymes,...
is a potent biowarfare agent, able to be highly lethal. The bacteria dwell in the soil of certain regions, as natural flora. Bacteriophages or their lytic enzymes, endolysins, may be an alternative for antibiotics and other antibacterials to fight this pathogen in infections and to minimize environmental contamination with anthrax endospores. Upon screening environmental samples from various regions in Poland, we isolated three new siphophages, J5a, F16Ba, and z1a, specific for They represent new species related to historical anthrax phages Gamma, Cherry, and Fah, and to phage Wbeta of genus. We show that the new phages and their closest relatives, phages Tavor_SA, Negev_SA, and Carmel_SA, form a separate clade of the genus, designated as J5a clade. The most distinctive feature of J5a clade phages is their cell lysis module. While in the historical phages it encodes a canonical endolysin and a class III holin, in J5a clade phages it encodes an endolysin with a signal peptide and two putative holins. We present the basic characteristic of the isolated phages. Their comparative genomic analysis indicates that they encode two receptor-binding proteins, of which one may bind a sugar moiety of cell surface.
Topics: Bacillus anthracis; Bacterial Proteins; Bacteriophages; Genome, Viral; Genomics; Phylogeny; Receptors, Virus; Siphoviridae; Viral Proteins
PubMed: 35215807
DOI: 10.3390/v14020213 -
Journal of Bacteriology Dec 2015Bacillus anthracis, a spore-forming pathogen, replicates as chains of vegetative cells by regulating the separation of septal peptidoglycan. Surface (S)-layer proteins...
UNLABELLED
Bacillus anthracis, a spore-forming pathogen, replicates as chains of vegetative cells by regulating the separation of septal peptidoglycan. Surface (S)-layer proteins and B. anthracis S-layer-associated proteins (BSLs) function as chain length determinants and are assembled in the envelope by binding to the secondary cell wall polysaccharide (SCWP). B. anthracis expresses six different genes encoding LytR-CpsA-Psr (LCP) enzymes (lcpB1 to -4, lcpC, and lcpD), which when expressed in Staphylococcus aureus promote attachment of wall teichoic acid to peptidoglycan. Mutations in B. anthracis lcpB3 and lcpD cause aberrations in cell size and chain length that can be explained as discrete defects in SCWP assembly; however, the function of the other lcp genes is not known. By deleting combinations of lcp genes from the B. anthracis genome, we generated variants with single lcp genes. B. anthracis expressing lcpB3 alone displayed physiological cell size, vegetative growth, spore formation, and S-layer assembly. Strains expressing lcpB1 or lcpB4 displayed defects in cell size and shape, S-layer assembly, and spore formation yet sustained vegetative growth. In contrast, the lcpB2 strain was unable to grow unless the gene was expressed from a multicopy plasmid (lcpB2(++)), and variants expressing lcpC or lcpD displayed severe defects in growth and cell shape. The lcpB2(++), lcpC, or lcpD strains supported neither S-layer assembly nor spore formation. We propose a model whereby LCP enzymes fulfill partially overlapping functions in transferring SCWP molecules to discrete sites within the bacterial envelope.
IMPORTANCE
Products of genes essential for bacterial envelope assembly represent targets for antibiotic development. The LytR-CpsA-Psr (LCP) enzymes tether bactoprenol-linked intermediates of secondary cell wall polymers to the C6 hydroxyl of N-acetylmuramic acid in peptidoglycan; however, the role of LCPs as a target for antibiotic therapy is not defined. We show here that LCP enzymes are essential for the cell cycle, vegetative growth, and spore formation of Bacillus anthracis, the causative agent of anthrax disease. Furthermore, we assign functions for each of the six LCP enzymes, including cell size and shape, vegetative growth and sporulation, and S-layer and S-layer-associated protein assembly.
Topics: Bacillus anthracis; Bacterial Proteins; Cell Division; Cell Wall; Membrane Glycoproteins; Spores, Bacterial
PubMed: 26391207
DOI: 10.1128/JB.00656-15 -
Journal of Bacteriology Nov 2021Anthrax disease is caused by infection with the bacteria Bacillus anthracis which, if left untreated, can result in fatal bacteremia and toxemia. Current treatment for...
Anthrax disease is caused by infection with the bacteria Bacillus anthracis which, if left untreated, can result in fatal bacteremia and toxemia. Current treatment for infection requires prolonged administration of antibiotics. Despite this, inhalational and gastrointestinal anthrax still result in lethal disease. By identifying key metabolic steps that B. anthracis uses to grow in host-like environments, new targets for antibacterial strategies can be identified. Here, we report that the gene, which encodes dihydroxyacid dehydratase in the putative pathway for synthesizing branched chain amino acids, is necessary for B. anthracis to synthesize isoleucine in an otherwise limiting microenvironment. We observed that Δ B. anthracis cannot grow in media lacking isoleucine, but growth is restored when exogenous isoleucine is added. In addition, bacilli are unable to utilize human hemoglobin or serum albumin to overcome isoleucine auxotrophy, but can when provided with the murine forms. This species-specific effect is due to the lack of isoleucine in human hemoglobin. Furthermore, even when supplemented with physiological levels of human serum albumin, apotransferrin, fibrinogen, and IgG, the knockout strain grew poorly relative to nonsupplemented wild type. In addition, comparisons upon infecting humanized mice suggest that murine hemoglobin is a key source of isoleucine for both WT and Δ bacilli. Further growth comparisons in murine and human blood show that the auxotrophy is detrimental for growth in human blood, not murine. This report identifies as necessary for isoleucine production in B. anthracis, and that it plays a key role in allowing the bacilli to effectively grow in isoleucine poor hosts. Anthrax disease, caused by B. anthracis, can cause lethal bacteremia and toxemia, even following treatment with antibiotics. This report identifies the gene, which encodes a dihydroxyacid dehydratase, as necessary for B. anthracis to synthesize the amino acid isoleucine in a nutrient-limiting environment, such as its mammalian host. The use of this strain further demonstrated a unique species-dependent utilization of hemoglobin as an exogenous source of extracellular isoleucine. By identifying mechanisms that B. anthracis uses to grow in host-like environments, new targets for therapeutic intervention are revealed.
Topics: Animals; Bacillus anthracis; Blood Proteins; Culture Media; Gene Deletion; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Enzymologic; Hemoglobins; Humans; Hydro-Lyases; Mice; Mutation
PubMed: 34570623
DOI: 10.1128/JB.00415-21 -
International Journal of Medical... Jul 2008Anthrax Euronet, a Coordination Action of the EU 6th Framework Programme, was designed to strengthen networking activities between anthrax research groups in Europe and... (Review)
Review
Anthrax Euronet, a Coordination Action of the EU 6th Framework Programme, was designed to strengthen networking activities between anthrax research groups in Europe and to harmonise protocols for testing anthrax vaccines and therapeutics. Inevitably, the project also addressed aspects of the current political issues of biosecurity and dual-use research, i.e. research into agents of important diseases of man, livestock or agriculture that could be used as agents of bioterrorism. This review provides a comprehensive overview of the biology of Bacillus anthracis, of the pathogenesis, epidemiology and diagnosis of anthrax, as well as vaccine and therapeutic intervention strategies. The proposed requirement for a code of conduct for working with dual-use agents such as the anthrax bacillus is also discussed.
Topics: Animals; Anthrax; Anthrax Vaccines; Bacillus anthracis; Humans; Virulence Factors
PubMed: 18375178
DOI: 10.1016/j.ijmm.2007.09.007 -
Microbiology (Reading, England) Jul 2010Recent observations have shed light on some of the endogenous iron-acquisition mechanisms of members of the Bacillus cereus sensu lato group. In particular, pathogens in... (Review)
Review
Recent observations have shed light on some of the endogenous iron-acquisition mechanisms of members of the Bacillus cereus sensu lato group. In particular, pathogens in the B. cereus group use siderophores with both unique chemical structures and biological roles. This review will focus on recent discoveries in siderophore biosynthesis and biology in this group, which contains numerous human pathogens, most notably the causative agent of anthrax, Bacillus anthracis.
Topics: Animals; Anthrax; Bacillus anthracis; Biological Transport; Humans; Iron; Siderophores
PubMed: 20466767
DOI: 10.1099/mic.0.039404-0 -
PloS One 2020To understand the epidemiological and genetic background of anthrax cases occurring in Vietnam from 2011 to 2015, we surveilled and genetically analyzed Bacillus...
To understand the epidemiological and genetic background of anthrax cases occurring in Vietnam from 2011 to 2015, we surveilled and genetically analyzed Bacillus anthracis isolated in the north of the country. Epidemiological surveillance showed that most human cutaneous anthrax cases occurred in association with animal dissection. Whole-genome sequences were obtained from six B. anthracis strains from human patients with cutaneous anthrax in the endemic area. Comparative genomic analysis showed that the genetic homogeneity among Vietnamese B. anthracis strains was very high. All Vietnamese B. anthracis strains belonged to the canSNP lineage of A.Br.011/009, which mostly consists of strains of the trans-Eurasian (TEA) group, including the most closely related strain, Carbosap. To clarify the genetic diversity of Vietnamese strains and strains belonging to A.Br.011/009 and A.Br.008/011 canSNP lineages, we applied a reference genome-based single-nucleotide polymorphism (SNP) and gene-by-gene genomic analysis (whole-genome MLST) strategy. The phylogeny from core genome SNPs revealed that the Vietnamese strains were positioned close to each other; moreover, several SNPs specific to Vietnamese B. anthracis were identified. Whole-genome MLST analysis revealed the differences in the number of SNPs between Vietnamese strains, which could enable discrimination at the strain level.
Topics: Anthrax; Bacillus anthracis; Genome, Bacterial; Genomics; Humans; Multilocus Sequence Typing; Phylogeny; Polymorphism, Single Nucleotide; Skin Diseases, Bacterial; Vietnam
PubMed: 32084143
DOI: 10.1371/journal.pone.0228116 -
MBio 2011In the fall of 2001, Bacillus anthracis spores were spread through letters mailed in the United States. Twenty-two people are known to have been infected, and five of...
In the fall of 2001, Bacillus anthracis spores were spread through letters mailed in the United States. Twenty-two people are known to have been infected, and five of these individuals died. Together with the September 11 attacks, this resulted in a reevaluation of the risks and benefits of life science research with the potential for misuse. In this editorial, we review some of the results of these discussions and their implications for the future.
Topics: Anthrax; Bacillus anthracis; Biomedical Research; Bioterrorism; Humans; Postal Service; Security Measures; United States
PubMed: 22027008
DOI: 10.1128/mBio.00232-11