Project description:Among the three major genetic lineages of L. monocytogenes (i.e. LI, LII, and LIII), LI and LII are predominantly associated with foodborne listeriosis outbreaks, whereas LIII is rarely implicated in human infections. In a previous study, we identified a Crp/Fnr family transcription factor lmo0753 that was highly specific to outbreak-associated LI and LII but absent from LIII. Lmo0753 shares two conserved functional domains including a DNA-binding domain with the well-characterized master virulence regulator PrfA in L. monocytogenes. In this study, we constructed a lmo0753 deletion and complementation mutants of the fully sequenced L. monocytogenes LII strain EGDe. We found that deletion of lmo0753 led to the loss of L-rhamnose utilization in EGDe. Transcriptomic comparison of the EGDe lmo0753 deletion mutant and the wild type incubated in phenol-red medium containing L-rhamnose as the sole carbon source revealed 126 (4.5%) and 546 (19.5%) out of 2,798 genes in the EGDe genome that were up- and down-regulated for more than 2-fold, respectively. Genes involved in biotin biosynthesis, general stress response and rhamnose metabolism were shown to be differentially regulated by Lmo0753. Findings from this study may partially explain why LIII of L. monocytogenes is underrepresented in the environment and rarely associated with human listeriosis outbreaks due to the inability of rhamnose utilization. We report the transcriptomic profile of L. monocytogenes M-NM-^Tlmo0753 LII strain (EGDe) in broth media with L-rhamnose as the sole carbon source. Examination of deletion of Lmo0753 on L-rhamnose utilization in L. monocytogenes. Two biological replicates per WT and M-NM-^Tlmo0753.
Project description:Among the three major genetic lineages of L. monocytogenes (i.e. LI, LII, and LIII), LI and LII are predominantly associated with foodborne listeriosis outbreaks, whereas LIII is rarely implicated in human infections. In a previous study, we identified a Crp/Fnr family transcription factor lmo0753 that was highly specific to outbreak-associated LI and LII but absent from LIII. Lmo0753 shares two conserved functional domains including a DNA-binding domain with the well-characterized master virulence regulator PrfA in L. monocytogenes. In this study, we constructed a lmo0753 deletion and complementation mutants of the fully sequenced L. monocytogenes LII strain EGDe. We found that deletion of lmo0753 led to the loss of L-rhamnose utilization in EGDe. Transcriptomic comparison of the EGDe lmo0753 deletion mutant and the wild type incubated in phenol-red medium containing L-rhamnose as the sole carbon source revealed 126 (4.5%) and 546 (19.5%) out of 2,798 genes in the EGDe genome that were up- and down-regulated for more than 2-fold, respectively. Genes involved in biotin biosynthesis, general stress response and rhamnose metabolism were shown to be differentially regulated by Lmo0753. Findings from this study may partially explain why LIII of L. monocytogenes is underrepresented in the environment and rarely associated with human listeriosis outbreaks due to the inability of rhamnose utilization. We report the transcriptomic profile of L. monocytogenes Δlmo0753 LII strain (EGDe) in broth media with L-rhamnose as the sole carbon source.
Project description:Coxiella burnetii, a category B select agent, is endemic worldwide, except New Zealand. It causes annually several outbreaks of the zoonotic disease Q fever predominantly in small ruminants. To date, the lipopolysaccharide (LPS), besides a type IV secretion system (T4SS), is the only defined and characterized virulence determinant of C. burnetii. This surface molecule is used to distinguish between virulent (Ph I) and low-virulent (Ph II) organisms, the latter emerge only after frequent passaging in the laboratory. As an obligate intracellular pathogen, targeted genetic modification is still not a routine and labour intensive procedure. The deeper study of novel determinants is complicated and demands not only advanced techniques for axenic and for cell culture-based cultivation but also novel approaches in the high-resolution mass spectrometry. This work is the first proteomic study comparing. C. burnetii Ph I and Ph II propagated in different axenic media and in cell culture.
Project description:Expression profiling by microarray was used with a murine listeriosis model to better understand increased susceptibility of preterm neonates to infection. We used DNA microarray to identify genes that were differentially expressed in liver of adult and neonatal Balb/c mice after listeriosis infection.
Project description:To investigate the evolutionary changes of regulatory elements in ruminants, we then performed regulatory elements profiling analysis using ChIP-seq datasets (H3K27ac and H3K4me3) of liver from three ruminants.
2022-09-15 | GSE206736 | GEO
Project description:Mycoplasma ovipneumoniae isolates from small ruminants in France
| PRJNA641331 | ENA
Project description:Comparative metagenomic analysis of small ruminants' fecal microbiota
Project description:Listeria monocytogenes strain F2365 was the first strain representative of serotype 4b (lineage I) to be sequenced in 2004, suggesting it could become the model organism for this serotype, which is associated with most human outbreaks of listeriosis worldwide to date. F2365 itself is an outbreak strain involved in the Mexican-style soft cheese outbreak in California in 1985. In this study we show through phenotypic and transcriptomic analysis that L. monocytogenes strain F2365 has reduced ability to respond to stress due to the absence of a functional σB-dependent stress response system. F2365 shows no B-dependent ability to survive acid or oxidative stress nor B-dependent ability to infect Caco-2 epithelial cell in vitro or guinea pigs in vivo. Therefore, there is substantial evidence that F2365 is an atypical strain and is not a suitable representative of outbreak-associated serotype 4b strains.
2013-06-01 | GSE42730 | GEO
Project description:Discovery of novel astrovirus genotype species in small ruminants