Showing papers on "Bacillus anthracis published in 1995"
Journal Article•
TL;DR: Review of the properties of spores of B. anthracis and other Bacillus species suggests that the specific soil factors linked to epidemic areas reflect important environmental conditions that aid the anthrax spores in causing epidemics.
Abstract: Bacillus anthracis is the causative agent of anthrax, a serious and often fatal disease of wild and domestic animals. Central to the persistence of anthrax in an area is the ability of B. anthracis to form long-lasting, highly resistant spores. Understanding the ecology of anthrax spores is essential if one hopes to control epidemics. Studies on the ecology of anthrax have found a correlation between the disease and specific soil factors, such as alkaline pH, high moisture, and high organic content. Researchers initially suggested that these factors influenced vegetative anthrax bacilli. However, subsequent research has shown that vegetative cells of B. anthracis have very specific nutrient and physiological requirements and are unlikely to survive outside a host. Review of the properties of spores of B. anthracis and other Bacillus species suggests that the specific soil factors linked to epidemic areas reflect important environmental conditions that aid the anthrax spores in causing epidemics. Specifically, high levels of calcium in the soil may help to maintain spore vitality for prolonged periods, thereby increasing the chance of spores encountering and infecting a new host. Cycles of runoff and evaporation may collect spores dispersed from previous epidemics into storage areas, thereby concentrating them. Uptake of large doses of viable spores from storage areas by susceptible animals, via altered feeding or breeding behavior, may then allow the bacterium to establish infection and cause a new epidemic. Literature search for this review was done by scanning the Life Sciences Collection 1982-1994 using the keywords "anthrax" and "calcium and spore."
261 citations
Journal Article•
TL;DR: In this study, compared with previous reports, meningitis and mesenteric lymph node hemorrhages were more common, whereas mediastinal and tracheobronchial lymph nodes hemorrhage were less common.
164 citations
TL;DR: It is shown that transcription of atx A does not appear to differ in cells grown in 5% CO2 compared with cells growing in air, and the antibody response to all three toxin proteins is decreased significantly in atX A‐null mutant‐infected mice, suggesting that the atx B gene product also regulates toxin gene expression during infection.
Abstract: Bacillus anthracis plasmid pXO1 carries the structural genes for the three anthrax toxin proteins, cya (edema factor), lef (lethal factor), and pag (protective antigen). Expression of the toxin genes by B. anthracis is enhanced during growth under elevated levels of CO2. This CO2 effect is observed only in the presence of another pXO1 gene, atxA, which encodes a transactivator of anthrax toxin synthesis. Here we show that transcription of atxA does not appear to differ in cells grown in 5% CO2 compared with cells grown in air. Using a new efficient method for gene replacement in B. anthracis, we constructed an atxA-null mutant in which the atxA-coding sequence on pXO1 is replaced with an omega km-2 cassette. Transcription of all three toxin genes is decreased in the absence of atxA. The pag gene possesses two apparent transcription start sites, P1 and P2; only transcripts with 5' ends mapping to P1 are decreased in the atxA-null mutant. Deletion analysis of the pag promoter region indicates that the 111 bp region upstream of the P1 site is sufficient for atxA-mediated activation of this transcript. The cya and lef genes each have one apparent start site for transcription. Transcripts with 5' ends mapping to these sites are not detected in the atxA-null mutant. The atxA-null mutant is avirulent in mice. Moreover, the antibody response to all three toxin proteins is decreased significantly in atxA-null mutant-infected mice. These data suggest that the atxA gene product also regulates toxin gene expression during infection.
161 citations
TL;DR: The gene coding for the S-layer protein (sap) was cloned on two contiguous fragments in Escherichia coli, and the complete sequence of the structural gene was determined.
Abstract: Bacillus anthracis, a gram-positive, spore-forming bacterium, is the etiological agent of anthrax. The gene coding for the S-layer protein (sap) was cloned on two contiguous fragments in Escherichia coli, and the complete sequence of the structural gene was determined. The protein, Sap, is composed of 814 residues, including a classical prokaryotic 29-amino-acid signal peptide. The mature form has a calculated molecular mass of 83.7 kDa and a molecular mass of 94 kDa on a sodium dodecyl sulfate-polyacrylamide gel. Sap possesses many charged residues, is weakly acidic, and contains only 0.9% methionine and no cysteine residues. The N-terminal region of Sap shares sequence similarities with the Acetogenium kivui S-layer protein, the Bacillus brevis middle wall protein, the Thermotoga maritima Omp alpha protein, and the Bacillus thuringiensis S-layer protein. Electron microscopy observations showed that this S-layer is not observed on B. anthracis cells in which sap has been deleted.
155 citations
TL;DR: It is concluded that methods such as PFGE and sequences of ISRs may be useful in separating B. anthracis from closely related species, but more sensitive methods are needed for strain identification.
Abstract: We evaluated the abilities of pulsed-field gel electrophoresis (PFGE) and sequences of intergenic spacer regions (ISRs) between two highly conserved genes, 16S-23S rDNA and gyrB-gyrA ISRs, to detect variation in strains of Bacillus anthracis as well as two closely related species, B cereus ATCC 14579 and B mycoides ATCC 6462 For each restriction enzyme, (NotI, SfiI, and SmaI), the PFGE banding patterns for three B anthracis strains (Ames, Vollum, and Sterne) were identical However, closely related species could be differentiated from B anthracis and from each other PCR amplification of the 16S-23S rDNA ISR yielded a 143- to 144-bp fragment, showing identical sequences for B anthracis strains, one nucleotide deletion between B cerus and B anthracis, and 13 nucleotide differences between B mycoides and B anthracis The gyrase ISR sequences (121 bp) in B anthracis strains were also identical, but those in B cereus and B mycoides differed from that in B anthracis by 1 and 2 nucleotides, respectively, and from each other by only 1 nucleotide Given the diverse geographic origins of these B anthracis strains, this species is very homogenous We conclude that methods such as PFGE and sequences of ISRs may be useful in separating B anthracis from closely related species, but more sensitive methods are needed for strain identification of B anthracis
154 citations
TL;DR: The PA+MPL in SLT vaccine, which was lyophilized and then reconstituted before use, demonstrated strong protective immunogenicity, even after storage for 2 years at 4 degrees C, and the MPL component was required for maximum efficacy of the vaccine.
126 citations
TL;DR: The antibody response to the in vivo production of PA, LF, and EF in mice immunized with spores of mutant strains is examined to confirm the role of PA as the major protective antigen in the humoral response but also indicate a significant contribution of LF and EF to immunoprotection.
Abstract: The two toxins secreted by Bacillus anthracis are composed of binary combinations of three proteins: protective antigen (PA), lethal factor (LF), and edema factor (EF). Six mutant strains that are deficient in the production of one or two of these toxin components have been previously constructed and characterized (C. Pezard, E. Duflot, and M. Mock, J. Gen. Microbiol. 139:2459-2463, 1993). In this work, we examined the antibody response to the in vivo production of PA, LF, and EF in mice immunized with spores of strains producing these proteins. High titers of antibody to PA were observed after immunization with all strains producing PA, while titers of antibodies to EF and LF were weak in animals immunized with strains producing only EF or LF. In contrast, immunization with strains producing either PA and EF or PA and LF resulted in an increased antibody response to EF or LF, respectively. The differing levels of protection from a lethal anthrax challenge afforded to mice immunized with spores of the mutant strains not only confirm the role of PA as the major protective antigen in the humoral response but also indicate a significant contribution of LF and EF to immunoprotection. We observed, however, that PA-deficient strains were also able to provide some protection, thereby suggesting that immune mechanisms other than the humoral response may be involved in immunity to anthrax. Finally, a control strain lacking the toxin-encoding plasmid was unable to provide protection or elicit an antibody response against bacterial antigens, indicating a possible role for pXO1 in the survival of B. anthracis in a host.
116 citations
TL;DR: A nested PCR has been developed to detect Bacillus anthracis spores in natural soil and waste samples which may be heavily contaminated by organic and inorganic compounds as is the case at former tannery sites.
69 citations
TL;DR: In this paper, sequence based on the conserved 20 bp inverted repeat of IS231 variants were used as polymerase chain reaction-based fingerprinting primers of the member species of the Bacillus cereus group (B. anthracis, B. thuringiensis and B. mycoides).
Abstract: Sequences based on the conserved 20 bp inverted repeat of IS231 variants were used as polymerase chain reaction-based fingerprinting primers of the member species of the Bacillus cereus group (B. anthracis, B. cereus, B. thuringiensis and B. mycoides), because of their close association with transposons, principally Tn4430 in B. thuringiensis. Fingerprints of B. anthracis were simple, and specifically allowed its identification and sub-differentiation from other members of the group. Fingerprints for B. cereus were strain-specific; those for B. thuringensis gave a 1650 bp product, characteristic of 1S231 variants A-F. The same reaction conditions gave one or two bands for both B. anthracis and B. cereus that differed by restriction endonuclease mapping from the B. thuringiensis PCR product and established IS231 restriction maps; this does not preclude some kind of relationship between these products and IS231.
64 citations
TL;DR: The data presented indicate that DNA containing methylated adenine residues is restricted in the B. anthracis strains studied here, resulting in decreased plasmid DNA-mediated transformation frequencies, which could be alleviated by propagating plasmids species in MTase-deficient (dam) strains of E. coli.
47 citations
TL;DR: Rec recombination in B. anthracis was found to be very efficient (approximately 10(-2) recombinants per transconjugant cell) and single integration of a suicide plasmid can be distinguished from multiple integration according to the level of resistance to an appropriate antibiotic.
TL;DR: The potential of the Biolog system for the identification of Bacillus anthracis was evaluated and 20% of all the strains of bacilli examined during the study gave unreadable reaction profiles due to false‐positive reactions.
Abstract: The potential of the Biolog system for the identification of Bacillus anthracis was evaluated. In-house generated databases allowed the correct identification of 19 of 20 isolates of B. anthracis within 24 h. Five strains of the closely related B. cereus/thuringiensis group were misidentified as B. anthracis. For this reason the test could only serve as a primary screen with further testing being required to confirm identity. In addition 20% of all the strains of bacilli examined during the study gave unreadable reaction profiles due to false-positive reactions.
TL;DR: Sequences based on the conserved 20 bp inverted repeat of IS231 variants were used as polymerase chain reaction-based fingerprinting primers of the member species of the Bacillus cereus group, and specifically allowed its identification and sub-differentiation from other members of the group.
Abstract: Sequences based on the conserved 20 bp inverted repeat of IS231 variants were used as polymerase chain reaction-based fingerprinting primers of the member species of the Bacillus cereus group (B. anthracis, B. cereus, B. thuringiensis and B. mycoides), because of their close association with transposons, principally Tn4430 in B. thuringiensis. Fingerprints of B. anthracis were simple, and specifically allowed its identification and sub-differentiation from other members of the group. Fingerprints for B. cereus were strain-specific; those for B. thuringensis gave a 1650 bp product, characteristic of 1S231 variants A-F. The same reaction conditions gave one or two bands for both B. anthracis and B. cereus that differed by restriction endonuclease mapping from the B. thuringiensis PCR product and established IS231 restriction maps; this does not preclude some kind of relationship between these products and IS231.
TL;DR: A 63-year-old man developed black crusts on the parietal scalp that showed mixed infections of dermatophytes and Bacillus anthracis on culture that improved with bifonazole, griseofulvin and bacampicillin hydrochloride.
Abstract: NATORI, N. A Case of Cutaneous Anthrax. Tohoku J. Exp. Med., 1995, 176 (3), 187-190-A 63-year-old man developed black crusts on the parietal scalp that showed mixed infections of dermatophytes and Bacillus anthracis on culture. The lesions improved with bifonazole, griseofulvin and bacampicillin hydrochl oride. Although cutaneous anthrax is now a very rare disease, the mortality is high in untreated cases. If a patient has black crusts, anthrax should be differentiated firstly.