Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis.
Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain) and Côte d'Ivoire (CI strain). These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and...
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ftdoajarticles:oai:doaj.org/article:54a687e190e841529dc9d951e15e2a0d 2023-05-15T15:14:41+02:00 Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis. Christophe Brézillon Michel Haustant Susann Dupke Jean-Philippe Corre Angelika Lander Tatjana Franz Marc Monot Evelyne Couture-Tosi Gregory Jouvion Fabian H Leendertz Roland Grunow Michèle E Mock Silke R Klee Pierre L Goossens 2015-04-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0003455 https://doaj.org/article/54a687e190e841529dc9d951e15e2a0d EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC4382292?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0003455 https://doaj.org/article/54a687e190e841529dc9d951e15e2a0d PLoS Neglected Tropical Diseases, Vol 9, Iss 4, p e0003455 (2015) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2015 ftdoajarticles https://doi.org/10.1371/journal.pntd.0003455 2022-12-30T23:33:24Z Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain) and Côte d'Ivoire (CI strain). These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and pBCXO2, that are highly similar to the pXO1 and pXO2 plasmids of B. anthracis that encode the toxins and the polyglutamate capsule respectively. The virulence factors implicated in the pathogenicity of these B. cereus bv anthracis strains remain to be characterised. We tested their virulence by cutaneous and intranasal delivery in mice and guinea pigs; they were as virulent as wild-type B. anthracis. Unlike as described for pXO2-cured B. anthracis, the CA strain cured of the pBCXO2 plasmid was still highly virulent, showing the existence of other virulence factors. Indeed, these strains concomitantly expressed a hyaluronic acid (HA) capsule and the B. anthracis polyglutamate (PDGA) capsule. The HA capsule was encoded by the hasACB operon on pBCXO1, and its expression was regulated by the global transcription regulator AtxA, which controls anthrax toxins and PDGA capsule in B. anthracis. Thus, the HA and PDGA capsules and toxins were co-regulated by AtxA. We explored the respective effect of the virulence factors on colonisation and dissemination of CA within its host by constructing bioluminescent mutants. Expression of the HA capsule by itself led to local multiplication and, during intranasal infection, to local dissemination to the adjacent brain tissue. Co-expression of either toxins or PDGA capsule with HA capsule enabled systemic dissemination, thus providing a clear evolutionary advantage. Protection against infection by B. cereus bv anthracis required the same vaccination formulation as that used against B. anthracis. Thus, these strains, at the frontier between B. anthracis and B. cereus, provide insight into how the monomorphic B. anthracis may have emerged. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 9 4 e0003455 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Christophe Brézillon Michel Haustant Susann Dupke Jean-Philippe Corre Angelika Lander Tatjana Franz Marc Monot Evelyne Couture-Tosi Gregory Jouvion Fabian H Leendertz Roland Grunow Michèle E Mock Silke R Klee Pierre L Goossens Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain) and Côte d'Ivoire (CI strain). These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and pBCXO2, that are highly similar to the pXO1 and pXO2 plasmids of B. anthracis that encode the toxins and the polyglutamate capsule respectively. The virulence factors implicated in the pathogenicity of these B. cereus bv anthracis strains remain to be characterised. We tested their virulence by cutaneous and intranasal delivery in mice and guinea pigs; they were as virulent as wild-type B. anthracis. Unlike as described for pXO2-cured B. anthracis, the CA strain cured of the pBCXO2 plasmid was still highly virulent, showing the existence of other virulence factors. Indeed, these strains concomitantly expressed a hyaluronic acid (HA) capsule and the B. anthracis polyglutamate (PDGA) capsule. The HA capsule was encoded by the hasACB operon on pBCXO1, and its expression was regulated by the global transcription regulator AtxA, which controls anthrax toxins and PDGA capsule in B. anthracis. Thus, the HA and PDGA capsules and toxins were co-regulated by AtxA. We explored the respective effect of the virulence factors on colonisation and dissemination of CA within its host by constructing bioluminescent mutants. Expression of the HA capsule by itself led to local multiplication and, during intranasal infection, to local dissemination to the adjacent brain tissue. Co-expression of either toxins or PDGA capsule with HA capsule enabled systemic dissemination, thus providing a clear evolutionary advantage. Protection against infection by B. cereus bv anthracis required the same vaccination formulation as that used against B. anthracis. Thus, these strains, at the frontier between B. anthracis and B. cereus, provide insight into how the monomorphic B. anthracis may have emerged. |
format |
Article in Journal/Newspaper |
author |
Christophe Brézillon Michel Haustant Susann Dupke Jean-Philippe Corre Angelika Lander Tatjana Franz Marc Monot Evelyne Couture-Tosi Gregory Jouvion Fabian H Leendertz Roland Grunow Michèle E Mock Silke R Klee Pierre L Goossens |
author_facet |
Christophe Brézillon Michel Haustant Susann Dupke Jean-Philippe Corre Angelika Lander Tatjana Franz Marc Monot Evelyne Couture-Tosi Gregory Jouvion Fabian H Leendertz Roland Grunow Michèle E Mock Silke R Klee Pierre L Goossens |
author_sort |
Christophe Brézillon |
title |
Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis. |
title_short |
Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis. |
title_full |
Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis. |
title_fullStr |
Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis. |
title_full_unstemmed |
Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis. |
title_sort |
capsules, toxins and atxa as virulence factors of emerging bacillus cereus biovar anthracis. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2015 |
url |
https://doi.org/10.1371/journal.pntd.0003455 https://doaj.org/article/54a687e190e841529dc9d951e15e2a0d |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 9, Iss 4, p e0003455 (2015) |
op_relation |
http://europepmc.org/articles/PMC4382292?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0003455 https://doaj.org/article/54a687e190e841529dc9d951e15e2a0d |
op_doi |
https://doi.org/10.1371/journal.pntd.0003455 |
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PLOS Neglected Tropical Diseases |
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9 |
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4 |
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e0003455 |
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