Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolates
<p>Abstract</p> <p>Background</p> <p>Currently, food regulatory authorities consider all <it>Listeria monocytogenes</it> isolates as equally virulent. However, an increasing number of studies demonstrate extensive variations in virulence and pathogenicity of...
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2012-12-01
|
| Series: | BMC Microbiology |
| Online Access: | http://www.biomedcentral.com/1471-2180/12/304 |
| _version_ | 1818825101096779776 |
|---|---|
| author | Roche Sylvie M Grépinet Olivier Kerouanton Annaëlle Ragon Marie Leclercq Alexandre Témoin Stéphanie Schaeffer Brigitte Skorski Gilbert Mereghetti Laurent Le Monnier Alban Velge Philippe |
| author_facet | Roche Sylvie M Grépinet Olivier Kerouanton Annaëlle Ragon Marie Leclercq Alexandre Témoin Stéphanie Schaeffer Brigitte Skorski Gilbert Mereghetti Laurent Le Monnier Alban Velge Philippe |
| author_sort | Roche Sylvie M |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Currently, food regulatory authorities consider all <it>Listeria monocytogenes</it> isolates as equally virulent. However, an increasing number of studies demonstrate extensive variations in virulence and pathogenicity of <it>L. monocytogenes</it> strains. Up to now, there is no comprehensive overview of the population genetic structure of <it>L. monocytogenes</it> taking into account virulence level. We have previously demonstrated that different low-virulence strains exhibit the same mutations in virulence genes suggesting that they could have common evolutionary pathways. New low-virulence strains were identified and assigned to phenotypic and genotypic Groups using cluster analysis. Pulsed-field gel electrophoresis, virulence gene sequencing and multi-locus sequence typing analyses were performed to study the genetic relatedness and the population structure between the studied low-virulence isolates and virulent strains.</p> <p>Results</p> <p>These methods showed that low-virulence strains are widely distributed in the two major lineages, but some are also clustered according to their genetic mutations. These analyses showed that low-virulence strains initially grouped according to their lineage, then to their serotypes and after which, they lost their virulence suggesting a relatively recent emergence.</p> <p>Conclusions</p> <p>Loss of virulence in lineage II strains was related to point mutation in a few virulence genes (<it>prfA, inlA, inlB, plcA</it>). These strains thus form a tightly clustered, monophyletic group with limited diversity. In contrast, low-virulence strains of lineage I were more dispersed among the virulence strains and the origin of their loss of virulence has not been identified yet, even if some strains exhibited different mutations in <it>prfA</it> or <it>inlA</it>.</p> |
| first_indexed | 2024-12-19T00:06:24Z |
| format | Article |
| id | doaj.art-2fc5645297c4410e852ee5fcd085c8fb |
| institution | Directory Open Access Journal |
| issn | 1471-2180 |
| language | English |
| last_indexed | 2024-12-19T00:06:24Z |
| publishDate | 2012-12-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Microbiology |
| spelling | doaj.art-2fc5645297c4410e852ee5fcd085c8fb2022-12-21T20:46:13ZengBMCBMC Microbiology1471-21802012-12-0112130410.1186/1471-2180-12-304Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolatesRoche Sylvie MGrépinet OlivierKerouanton AnnaëlleRagon MarieLeclercq AlexandreTémoin StéphanieSchaeffer BrigitteSkorski GilbertMereghetti LaurentLe Monnier AlbanVelge Philippe<p>Abstract</p> <p>Background</p> <p>Currently, food regulatory authorities consider all <it>Listeria monocytogenes</it> isolates as equally virulent. However, an increasing number of studies demonstrate extensive variations in virulence and pathogenicity of <it>L. monocytogenes</it> strains. Up to now, there is no comprehensive overview of the population genetic structure of <it>L. monocytogenes</it> taking into account virulence level. We have previously demonstrated that different low-virulence strains exhibit the same mutations in virulence genes suggesting that they could have common evolutionary pathways. New low-virulence strains were identified and assigned to phenotypic and genotypic Groups using cluster analysis. Pulsed-field gel electrophoresis, virulence gene sequencing and multi-locus sequence typing analyses were performed to study the genetic relatedness and the population structure between the studied low-virulence isolates and virulent strains.</p> <p>Results</p> <p>These methods showed that low-virulence strains are widely distributed in the two major lineages, but some are also clustered according to their genetic mutations. These analyses showed that low-virulence strains initially grouped according to their lineage, then to their serotypes and after which, they lost their virulence suggesting a relatively recent emergence.</p> <p>Conclusions</p> <p>Loss of virulence in lineage II strains was related to point mutation in a few virulence genes (<it>prfA, inlA, inlB, plcA</it>). These strains thus form a tightly clustered, monophyletic group with limited diversity. In contrast, low-virulence strains of lineage I were more dispersed among the virulence strains and the origin of their loss of virulence has not been identified yet, even if some strains exhibited different mutations in <it>prfA</it> or <it>inlA</it>.</p>http://www.biomedcentral.com/1471-2180/12/304 |
| spellingShingle | Roche Sylvie M Grépinet Olivier Kerouanton Annaëlle Ragon Marie Leclercq Alexandre Témoin Stéphanie Schaeffer Brigitte Skorski Gilbert Mereghetti Laurent Le Monnier Alban Velge Philippe Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolates BMC Microbiology |
| title | Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolates |
| title_full | Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolates |
| title_fullStr | Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolates |
| title_full_unstemmed | Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolates |
| title_short | Polyphasic characterization and genetic relatedness of low-virulence and virulent <it>Listeria monocytogenes</it> isolates |
| title_sort | polyphasic characterization and genetic relatedness of low virulence and virulent it listeria monocytogenes it isolates |
| url | http://www.biomedcentral.com/1471-2180/12/304 |
| work_keys_str_mv | AT rochesylviem polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT grepinetolivier polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT kerouantonannaelle polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT ragonmarie polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT leclercqalexandre polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT temoinstephanie polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT schaefferbrigitte polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT skorskigilbert polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT mereghettilaurent polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT lemonnieralban polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates AT velgephilippe polyphasiccharacterizationandgeneticrelatednessoflowvirulenceandvirulentitlisteriamonocytogenesitisolates |