Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment.
The bacteriophage life cycle has an important role in Shiga toxin (Stx) expression. The induction of Shiga toxin-encoding phages (Stx phages) increases toxin production as a result of replication of the phage genome, and phage lysis of the host cell also provides a means of Stx toxin to exit the cel...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3290563?pdf=render |
| _version_ | 1811331742870536192 |
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| author | Lejla Imamovic Maite Muniesa |
| author_facet | Lejla Imamovic Maite Muniesa |
| author_sort | Lejla Imamovic |
| collection | DOAJ |
| description | The bacteriophage life cycle has an important role in Shiga toxin (Stx) expression. The induction of Shiga toxin-encoding phages (Stx phages) increases toxin production as a result of replication of the phage genome, and phage lysis of the host cell also provides a means of Stx toxin to exit the cell. Previous studies suggested that prophage induction might also occur in the absence of SOS response, independently of RecA.The influence of EDTA on RecA-independent Stx2 phage induction was assessed, in laboratory lysogens and in EHEC strains carrying Stx2 phages in their genome, by Real-Time PCR. RecA-independent mechanisms described for phage λ induction (RcsA and DsrA) were not involved in Stx2 phage induction. In addition, mutations in the pathway for the stress response of the bacterial envelope to EDTA did not contribute to Stx2 phage induction. The effect of EDTA on Stx phage induction is due to its chelating properties, which was also confirmed by the use of citrate, another chelating agent. Our results indicate that EDTA affects Stx2 phage induction by disruption of the bacterial outer membrane due to chelation of Mg(2+). In all the conditions evaluated, the pH value had a decisive role in Stx2 phage induction.Chelating agents, such as EDTA and citrate, induce Stx phages, which raises concerns due to their frequent use in food and pharmaceutical products. This study contributes to our understanding of the phenomenon of induction and release of Stx phages as an important factor in the pathogenicity of Shiga toxin-producing Escherichia coli (STEC) and in the emergence of new pathogenic strains. |
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| id | doaj.art-ea66c0267e744c3ba22e08ce723384d0 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-13T16:25:18Z |
| publishDate | 2012-01-01 |
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| spelling | doaj.art-ea66c0267e744c3ba22e08ce723384d02022-12-22T02:39:45ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0172e3239310.1371/journal.pone.0032393Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment.Lejla ImamovicMaite MuniesaThe bacteriophage life cycle has an important role in Shiga toxin (Stx) expression. The induction of Shiga toxin-encoding phages (Stx phages) increases toxin production as a result of replication of the phage genome, and phage lysis of the host cell also provides a means of Stx toxin to exit the cell. Previous studies suggested that prophage induction might also occur in the absence of SOS response, independently of RecA.The influence of EDTA on RecA-independent Stx2 phage induction was assessed, in laboratory lysogens and in EHEC strains carrying Stx2 phages in their genome, by Real-Time PCR. RecA-independent mechanisms described for phage λ induction (RcsA and DsrA) were not involved in Stx2 phage induction. In addition, mutations in the pathway for the stress response of the bacterial envelope to EDTA did not contribute to Stx2 phage induction. The effect of EDTA on Stx phage induction is due to its chelating properties, which was also confirmed by the use of citrate, another chelating agent. Our results indicate that EDTA affects Stx2 phage induction by disruption of the bacterial outer membrane due to chelation of Mg(2+). In all the conditions evaluated, the pH value had a decisive role in Stx2 phage induction.Chelating agents, such as EDTA and citrate, induce Stx phages, which raises concerns due to their frequent use in food and pharmaceutical products. This study contributes to our understanding of the phenomenon of induction and release of Stx phages as an important factor in the pathogenicity of Shiga toxin-producing Escherichia coli (STEC) and in the emergence of new pathogenic strains.http://europepmc.org/articles/PMC3290563?pdf=render |
| spellingShingle | Lejla Imamovic Maite Muniesa Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment. PLoS ONE |
| title | Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment. |
| title_full | Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment. |
| title_fullStr | Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment. |
| title_full_unstemmed | Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment. |
| title_short | Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment. |
| title_sort | characterizing reca independent induction of shiga toxin2 encoding phages by edta treatment |
| url | http://europepmc.org/articles/PMC3290563?pdf=render |
| work_keys_str_mv | AT lejlaimamovic characterizingrecaindependentinductionofshigatoxin2encodingphagesbyedtatreatment AT maitemuniesa characterizingrecaindependentinductionofshigatoxin2encodingphagesbyedtatreatment |