Redox proteomic study of Bacillus cereus thiol proteome during fermentative anaerobic growth.

Background: Bacillus cereus is a notorious foodborne pathogen, which can grow under anoxic conditions. Anoxic growth is supported by endogenous redox metabolism, for which the thiol redox proteome serves as an interface. Here, we studied the cysteine (Cys) proteome dynamics of B.

Cysteine Proteome Reveals Response to Endogenous Oxidative Stress in .

At the end of exponential growth, aerobic bacteria have to cope with the accumulation of endogenous reactive oxygen species (ROS). One of the main targets of these ROS is cysteine residues in proteins. This study uses liquid chromatography coupled to high-resolution tandem mass spectrometry to detect significant changes in protein abundance and thiol status for cysteine-containing proteins from during aerobic exponential growth.

Antibacterial Mode of Action of the Essential Oil Active Compounds against and Efflux-Mediated Drug Resistance in Gram-Negative Bacteria.

Today, an alarming rise of bacterial gastroenteritis in humans resulting from consuming -tainted foods is being observed. One of the solutions for mitigating this issue may be the antibacterial activity of essential oils. In the present research, we propose to study the antibacterial activity against and other Gram-negative bacteria of essential oil and its active molecules.

B cells response directed against Cut4 and CFP21 lipolytic enzymes in active and latent tuberculosis infections.

Background: Better understanding of the immune response directed against Mycobacterium tuberculosis (Mtb) is critical for development of vaccine strategies and diagnosis tests. Previous studies suggested that Mtb enzymes involved in lipid metabolism, are associated with persistence and/or reactivation of dormant bacilli.

Methods: Circulating antibodies secreting cells (ASCs), memory B cells, and antibodies directed against Cut4 (Rv3452) and CFP21 (Rv1984c) antigens were explored in subjects with either active- or latent-tuberculosis (LTB), and in Mtb-uninfected individuals.

Identification of residues involved in substrate specificity and cytotoxicity of two closely related cutinases from Mycobacterium tuberculosis.

The enzymes belonging to the cutinase family are serine enzymes active on a large panel of substrates such as cutin, triacylglycerols, and phospholipids. In the M. tuberculosis H37Rv genome, seven genes coding for cutinase-like proteins have been identified with strong immunogenic properties suggesting a potential role as vaccine candidates.

Regulation of cel genes of C. cellulolyticum: identification of GlyR2, a transcriptional regulator regulating cel5D gene expression.

Transcription and expression regulation of some individual cel genes (cel5A, cel5I, cel5D and cel44O) of Clostridium cellulolyticum were investigated. Unlike the cip-cel operon, these genes are transcribed as monocistronic units of transcription, except cel5D. The location of the transcription initiation sites was determined using RT-PCR and the mRNA 5'-end extremities were detected using primer extension experiments.

MmPPOX inhibits Mycobacterium tuberculosis lipolytic enzymes belonging to the hormone-sensitive lipase family and alters mycobacterial growth.

Lipid metabolism plays an important role during the lifetime of Mycobacterium tuberculosis, the causative agent of tuberculosis. Although M. tuberculosis possesses numerous lipolytic enzymes, very few have been characterized yet at a biochemical/pharmacological level.

Mycobacterium tuberculosis lipolytic enzymes as potential biomarkers for the diagnosis of active tuberculosis.

Background: New diagnosis tests are urgently needed to address the global tuberculosis (TB) burden and to improve control programs especially in resource-limited settings. An effective in vitro diagnostic of TB based on serological methods would be regarded as an attractive progress because immunoassays are simple, rapid, inexpensive, and may offer the possibility to detect cases missed by standard sputum smear microscopy. However, currently available serology tests for TB are highly variable in sensitivity and specificity.

The omp50 gene is transcriptionally controlled by a temperature-dependent mechanism conserved among thermophilic Campylobacter species.

The thermophilic Campylobacters are enteropathogenic for humans. We recently showed that Omp50 is a Campylobacter species-specific porin produced in Campylobacter jejuni and Campylobacter lari but not in Campylobacter coli. In the present study, we investigated regulation of the omp50 gene and found that its expression in C.

Chromosomal His-tagging: an alternative approach to membrane protein purification.

Membrane proteins are of keen interest to structural biologists, as they are known to act as receptors, adhesins, sensors, transporters, and signal-transducers of living cells. During the past few decades, the efforts made to study the bacterial membrane proteins have been impaired by the problems encountered during the production and purification of native proteins. Herein we demonstrate that the Campylobacter jejuni CadF protein, which was isolated using a novel purification strategy, exhibits biological activity as evidenced by channel activity in lipid bilayers.

Use of the omp50 gene for identification of Campylobacter species by PCR.

We studied the prevalence of the omp50 gene and the Omp50 protein in Campylobacter strains. Immunodetection assays and DNA-DNA hybridizations showed that most C. coli strains tested were negative and most C.

Environmental regulation of Campylobacter jejuni major outer membrane protein porin expression in Escherichia coli monitored by using green fluorescent protein.

Porins allow exchanges between bacteria and their environment. In the gram-negative food-borne pathogen Campylobacter jejuni two porins, major outer membrane protein (MOMP) and Omp50, have been identified. MOMP is synthesized at a very high level under laboratory culture conditions, suggesting that its promoter functions very efficiently under these conditions.