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| Status |
Public on Jun 01, 2010 |
| Title |
Sigma B in Listeria monocytogenes strains from different lineages |
| Organism |
Listeria monocytogenes |
| Experiment type |
Expression profiling by array
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| Summary |
Listeria monocytogenes strains classify into at least three distinct phylogenetic lineages. Correlations exist between lineage classification and source of bacterial isolation, e.g., human clinical and food isolates usually classify into either lineage I or II, however, human clinical isolates are over-represented in lineage I while food isolates are over-represented in lineage II. σB, a transcriptional regulator previously demonstrated to contribute to environmental stress response and virulence in L. monocytogenes lineage II strains, was hypothesized to provide differential capabilities for L. monocytogenes survival in various niches (e.g., food vs. human clinical). To determine if σB contributions to stress response and virulence differ across diverse L. monocytogenes strains, ΔsigB mutations were created in strains from lineages I, II, IIIA, and IIIB. Paired parent and ΔsigB mutant strains were tested for acid and oxidative stress survival, Caco-2 cell invasion efficiency, and virulence using the guinea pig listeriosis infection model. Parent and ΔsigB mutant strain transcriptomes were compared using whole-genome expression microarrays. σB contributed to virulence in each strain. However, while σB contributed significantly to acid and oxidative stress survival and Caco-2 cell invasion in lineage I, II, and IIIB strains, σB contributions were not significant for these phenotypes in the lineage IIIA strain. A core set of 63 genes was positively regulated by σB in all four strains; different total numbers of genes were positively regulated by σB in each strain. Our results suggest that σB universally contributes to L. monocytogenes virulence, but specific σB-regulated stress response phenotypes vary among strains.
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| Overall design |
Independent RNA isolations were performed for four wildtype and ΔsigB strains from cells grown to early stationary phase. Three biological replicates were used in competitive whole-genome microarray experiments. For each set of hybridizations, RNA from a L. monocytogenes wildtype strain was hybridized with RNA from its isogenic ΔsigB null mutant. Four wildtype and ΔsigB isogenic pairs were compared independently.
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| Contributor(s) |
Oliver HF, Orsi RH, Wiedmann M, Boor KJ |
| Citation(s) |
20453120 |
| Submission date |
Apr 21, 2010 |
| Last update date |
Mar 22, 2012 |
| Contact name |
Haley Franks Oliver |
| E-mail(s) |
haf9@cornell.edu
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| Organization name |
Cornell University
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| Department |
Food Science
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| Lab |
Boor
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| Street address |
410 Stocking
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| City |
Ithaca |
| State/province |
NY |
| ZIP/Postal code |
14853 |
| Country |
USA |
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| Platforms (1) |
| GPL4281 |
JCVI PFGRC Listeria monocytogenes 27K v2 array designed primarily based on strain EGD-e |
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| Samples (4)
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| GSM535669 |
Lineage I wildtype compared to sigma B null mutant |
| GSM535676 |
Lineage II wildtype compared to sigma B null mutant |
| GSM535677 |
Lineage IIIA wildtype compared to sigma B null mutant |
| GSM535678 |
Lineage IIIB wildtype compared to sigma B null mutant |
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| Relations |
| BioProject |
PRJNA126383 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE21427_RAW.tar |
37.5 Mb |
(http)(custom) |
TAR (of GPR) |
| Processed data included within Sample table |
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