Myriam Gominet

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Members of the Bacillus cereus group (B. anthracis, B. cereus, B. mycoides and B. thuringiensis) are well-known pathogens of mammals (B. anthracis and B. cereus) and insects (B. thuringiensis). The specific diseases they cause depend on their capacity to produce specific virulence factors, such as the lethal toxin of B. anthracis and the Cry toxins of B.(More)
PlcR is a Bacillus cereus transcriptional regulator, which activates gene expression by binding to a nucleotidic sequence called the 'PlcR box'. To build a list of all genes included in the PlcR regulon, a consensus sequence was identified by directed mutagenesis. The reference strain ATCC14579 sequenced genome was searched for occurrences of this consensus(More)
A transcriptional analysis of the phosphatidylinositol-specific phospholipase C (plcA) gene of Bacillus thuringiensis indicated that its transcription was activated at the onset of the stationary phase in B. thuringiensis but was not activated in B. subtilis. The B. thuringiensis gene encoding a transcriptional activator required for plcA expression was(More)
Bacillus thuringiensis has been widely used for 40 years as a safe biopesticide for controlling agricultural pests and mosquitoes because it produces insecticidal crystal proteins. However, spores have also been shown to contribute to overall entomopathogenicity. Here, the opportunistic properties of acrystalliferous B. thuringiensis Cry(-) and Bacillus(More)
In sporulating Bacillus, major processes like virulence gene expression and sporulation are regulated by communication systems involving signalling peptides and regulators of the RNPP family. We investigated the role of one such regulator, NprR, in bacteria of the Bacillus cereus group. We show that NprR is a transcriptional regulator whose activity depends(More)
PlcR is a pleiotropic regulator of virulence factors in the insect pathogen Bacillus thuringiensis and in the opportunistic human pathogen Bacillus cereus. It activates the transcription of at least 15 genes encoding extracellular proteins, including phospholipases C, proteases and enterotoxins. Expression of the plcR gene is autoregulated and activated at(More)
Bacillus thuringiensis is a spore-forming bacterium well known for its insecticidal properties and its ability to produce a crystal inclusion during sporulation. The specific activity of B. thuringiensis against insect larvae is due to the crystal proteins (Cry proteins). Two different transcriptional mechanisms (dependent and independent of sporulation)(More)
It has been shown previously that expression of the Streptomyces lividans clpP1P2 operon, encoding proteolytic subunits of the Clp complex, the clpC1 gene, encoding the ATPase subunit, and the lon gene, encoding another ATP-dependent protease, are all activated by ClgR. The ClgR regulon also includes the clgR gene itself. It is shown here that the(More)
Bacillus thuringiensis is being used worldwide as a biopesticide, although increasing evidence suggests that it is emerging as an opportunistic human pathogen. While phospholipases, hemolysins, and enterotoxins are claimed to be responsible for B. thuringiensis virulence, there is no direct evidence to indicate that the flagellum-driven motility plays a(More)
PURPOSE Bacillus endophthalmitis is a highly explosive infection of the eye that commonly results in rapid inflammation and vision loss, if not loss of the eye itself, within a few days. Quorum-sensing-controlled toxins are essential to virulence during infection. Another unique characteristic of this disease is the ability of Bacillus to replicate rapidly(More)