Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine
Brucella melitensis Rev 1 is the best vaccine available for the prophylaxis of small ruminant brucellosis and, indirectly, for reducing human brucellosis. However, Rev 1 shows anomalously high rates of spontaneous dissociation from smooth (S) to rough (R) bacteria, the latter being inefficacious as...
| Main Authors: | , , , , , , |
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| Format: | info:eu-repo/semantics/article |
| Language: | eng |
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BioMed Central
2014
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| Online Access: | https://hdl.handle.net/10171/35589 |
| _version_ | 1793400152122195968 |
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| author | Mancilla, M. (Marcos) Grillo, M.J. (María Jesús) Miguel, M.J. (María Jesús) de Lopez-Goñi, I. (Ignacio) San-Roman, B. (Beatriz) Zabalza-Barangua, A. (Ana) Moriyon, I. (Ignacio) |
| author_facet | Mancilla, M. (Marcos) Grillo, M.J. (María Jesús) Miguel, M.J. (María Jesús) de Lopez-Goñi, I. (Ignacio) San-Roman, B. (Beatriz) Zabalza-Barangua, A. (Ana) Moriyon, I. (Ignacio) |
| author_sort | Mancilla, M. (Marcos) |
| collection | DSpace |
| description | Brucella melitensis Rev 1 is the best vaccine available for the prophylaxis of small ruminant brucellosis and, indirectly, for reducing human brucellosis. However, Rev 1 shows anomalously high rates of spontaneous dissociation from smooth (S) to rough (R) bacteria, the latter being inefficacious as vaccines. This S-R instability results from the loss of the O-polysaccharide. To overcome this problem, we investigated whether some recently described mechanisms promoting mutations in O-polysaccharide genes were involved in Rev 1 S-R dissociation. We found that a proportion of Rev 1 R mutants result from genome rearrangements affecting the wbo O-polysaccharide loci of genomic island GI-2 and the wbkA O-polysaccharide glycosyltransferase gene of the wbk region. Accordingly, we mutated the GI-2 int gene and the wbk IS transposase involved in those arrangements, and found that these Rev 1 mutants maintained the S phenotype and showed lower dissociation levels. Combining these two mutations resulted in a strain (Rev 2) displaying a 95% decrease in dissociation with respect to parental Rev 1 under conditions promoting dissociation. Rev 2 did not differ from Rev 1 in the characteristics used in Rev 1 typing (growth rate, colonial size, reactivity with O-polysaccharide antibodies, phage, dye and antibiotic susceptibility). Moreover, Rev 2 and Rev 1 showed similar attenuation and afforded similar protection in the mouse model of brucellosis vaccines. We conclude that mutations targeting genes and DNA sequences involved in spontaneous O-polysaccharide loss enhance the stability of a critical vaccine phenotype and complement the empirical stabilization precautions taken during S Brucella vaccine production. |
| format | info:eu-repo/semantics/article |
| id | oai:dadun.unav.edu:10171-35589 |
| institution | Universidad de Navarra |
| language | eng |
| publishDate | 2014 |
| publisher | BioMed Central |
| record_format | dspace |
| spelling | oai:dadun.unav.edu:10171-355892020-03-03T11:07:45Z Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine Mancilla, M. (Marcos) Grillo, M.J. (María Jesús) Miguel, M.J. (María Jesús) de Lopez-Goñi, I. (Ignacio) San-Roman, B. (Beatriz) Zabalza-Barangua, A. (Ana) Moriyon, I. (Ignacio) O-polysaccharide synthesis Gram-negative bacteria Smooth lipopolysaccharide DNA polymorphism Genomic island PCR assay Abortus Virulence Gene Identification Brucella melitensis Rev 1 is the best vaccine available for the prophylaxis of small ruminant brucellosis and, indirectly, for reducing human brucellosis. However, Rev 1 shows anomalously high rates of spontaneous dissociation from smooth (S) to rough (R) bacteria, the latter being inefficacious as vaccines. This S-R instability results from the loss of the O-polysaccharide. To overcome this problem, we investigated whether some recently described mechanisms promoting mutations in O-polysaccharide genes were involved in Rev 1 S-R dissociation. We found that a proportion of Rev 1 R mutants result from genome rearrangements affecting the wbo O-polysaccharide loci of genomic island GI-2 and the wbkA O-polysaccharide glycosyltransferase gene of the wbk region. Accordingly, we mutated the GI-2 int gene and the wbk IS transposase involved in those arrangements, and found that these Rev 1 mutants maintained the S phenotype and showed lower dissociation levels. Combining these two mutations resulted in a strain (Rev 2) displaying a 95% decrease in dissociation with respect to parental Rev 1 under conditions promoting dissociation. Rev 2 did not differ from Rev 1 in the characteristics used in Rev 1 typing (growth rate, colonial size, reactivity with O-polysaccharide antibodies, phage, dye and antibiotic susceptibility). Moreover, Rev 2 and Rev 1 showed similar attenuation and afforded similar protection in the mouse model of brucellosis vaccines. We conclude that mutations targeting genes and DNA sequences involved in spontaneous O-polysaccharide loss enhance the stability of a critical vaccine phenotype and complement the empirical stabilization precautions taken during S Brucella vaccine production. 2014-03-25T11:41:57Z 2014-03-25T11:41:57Z 2013 info:eu-repo/semantics/article https://hdl.handle.net/10171/35589 eng info:eu-repo/grantAgreement/EC/FP7/221948 info:eu-repo/semantics/openAccess info:eu-repo/semantics/openAccess application/pdf BioMed Central |
| spellingShingle | O-polysaccharide synthesis Gram-negative bacteria Smooth lipopolysaccharide DNA polymorphism Genomic island PCR assay Abortus Virulence Gene Identification Mancilla, M. (Marcos) Grillo, M.J. (María Jesús) Miguel, M.J. (María Jesús) de Lopez-Goñi, I. (Ignacio) San-Roman, B. (Beatriz) Zabalza-Barangua, A. (Ana) Moriyon, I. (Ignacio) Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine |
| title | Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine |
| title_full | Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine |
| title_fullStr | Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine |
| title_full_unstemmed | Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine |
| title_short | Deletion of the GI-2 integrase and the wbkA flanking transposase improves the stability of Brucella melitensis Rev 1 vaccine |
| title_sort | deletion of the gi-2 integrase and the wbka flanking transposase improves the stability of brucella melitensis rev 1 vaccine |
| topic | O-polysaccharide synthesis Gram-negative bacteria Smooth lipopolysaccharide DNA polymorphism Genomic island PCR assay Abortus Virulence Gene Identification |
| url | https://hdl.handle.net/10171/35589 |
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