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The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection
Burkholderia mallei is a highly pathogenic bacterium that causes the zoonosis glanders. Previous studies indicated that the genome of the organism contains eight genes specifying autotransporter proteins, which are important virulence factors of Gram-negative bacteria. In the present study, we repor...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2015
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4438868/ https://www.ncbi.nlm.nih.gov/pubmed/25993100 http://dx.doi.org/10.1371/journal.pone.0126437 |
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author | Zimmerman, Shawn M. Michel, Frank Hogan, Robert J. Lafontaine, Eric R. |
author_facet | Zimmerman, Shawn M. Michel, Frank Hogan, Robert J. Lafontaine, Eric R. |
author_sort | Zimmerman, Shawn M. |
collection | PubMed |
description | Burkholderia mallei is a highly pathogenic bacterium that causes the zoonosis glanders. Previous studies indicated that the genome of the organism contains eight genes specifying autotransporter proteins, which are important virulence factors of Gram-negative bacteria. In the present study, we report the characterization of one of these autotransporters, BpaB. Database searches identified the bpaB gene in ten B. mallei isolates and the predicted proteins were 99-100% identical. Comparative sequence analyses indicate that the gene product is a trimeric autotransporter of 1,090 amino acids with a predicted molecular weight of 105-kDa. Consistent with this finding, we discovered that recombinant bacteria expressing bpaB produce a protein of ≥300-kDa on their surface that is reactive with a BpaB-specific monoclonal antibody. Analysis of sera from mice infected with B. mallei indicated that animals produce antibodies against BpaB during the course of disease, thus establishing production of the autotransporter in vivo. To gain insight on its role in virulence, we inactivated the bpaB gene of B. mallei strain ATCC 23344 and determined the median lethal dose of the mutant in a mouse model of aerosol infection. These experiments revealed that the bpaB mutation attenuates virulence 8-14 fold. Using a crystal violet-based assay, we also discovered that constitutive production of BpaB on the surface of B. mallei promotes biofilm formation. To our knowledge, this is the first report of a biofilm factor for this organism. |
format | Online Article Text |
id | pubmed-4438868 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-44388682015-05-29 The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection Zimmerman, Shawn M. Michel, Frank Hogan, Robert J. Lafontaine, Eric R. PLoS One Research Article Burkholderia mallei is a highly pathogenic bacterium that causes the zoonosis glanders. Previous studies indicated that the genome of the organism contains eight genes specifying autotransporter proteins, which are important virulence factors of Gram-negative bacteria. In the present study, we report the characterization of one of these autotransporters, BpaB. Database searches identified the bpaB gene in ten B. mallei isolates and the predicted proteins were 99-100% identical. Comparative sequence analyses indicate that the gene product is a trimeric autotransporter of 1,090 amino acids with a predicted molecular weight of 105-kDa. Consistent with this finding, we discovered that recombinant bacteria expressing bpaB produce a protein of ≥300-kDa on their surface that is reactive with a BpaB-specific monoclonal antibody. Analysis of sera from mice infected with B. mallei indicated that animals produce antibodies against BpaB during the course of disease, thus establishing production of the autotransporter in vivo. To gain insight on its role in virulence, we inactivated the bpaB gene of B. mallei strain ATCC 23344 and determined the median lethal dose of the mutant in a mouse model of aerosol infection. These experiments revealed that the bpaB mutation attenuates virulence 8-14 fold. Using a crystal violet-based assay, we also discovered that constitutive production of BpaB on the surface of B. mallei promotes biofilm formation. To our knowledge, this is the first report of a biofilm factor for this organism. Public Library of Science 2015-05-20 /pmc/articles/PMC4438868/ /pubmed/25993100 http://dx.doi.org/10.1371/journal.pone.0126437 Text en © 2015 Zimmerman et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Zimmerman, Shawn M. Michel, Frank Hogan, Robert J. Lafontaine, Eric R. The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection |
title | The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection |
title_full | The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection |
title_fullStr | The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection |
title_full_unstemmed | The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection |
title_short | The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection |
title_sort | autotransporter bpab contributes to the virulence of burkholderia mallei in an aerosol model of infection |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4438868/ https://www.ncbi.nlm.nih.gov/pubmed/25993100 http://dx.doi.org/10.1371/journal.pone.0126437 |
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