Biofilm Formation in Streptococcus agalactiae Is Inhibited by a Small Regulatory RNA Regulated by the Two-Component System CiaRH.

Regulatory small RNAs (sRNAs) are involved in the adaptation of bacteria to their environment. CiaR-dependent sRNAs (csRNAs) are controlled by the regulatory two-component system (TCS) CiaRH, which is widely conserved in streptococci. Except for Streptococcus pneumoniae and Streptococcus sanguinis, the targets of these csRNAs have not yet been investigated.

Functional Study of the Type II-A CRISPR-Cas System of Hypervirulent Strains.

Nearly all strains of , the leading cause of invasive infections in neonates, encode a type II-A clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system. Interestingly, strains belonging to the hypervirulent Sequence Type 17 (ST17) contain significantly fewer spacers in their CRISPR locus than other lineages, which could be the result of a less functional CRISPR-Cas system. Here, we revealed one large deletion in the ST17 promoter region and we evaluated its impact on the transcription of genes as well as the functionalities of the CRISPR-Cas system.

Defining the Role of the Sht-Family Proteins in Zinc Acquisition and Complement Evasion.

is not only part of the human intestinal and urogenital microbiota but is also a leading cause of septicemia and meningitis in neonates. Its ability to cause disease depends upon the acquisition of nutrients from its environment, including the transition metal ion zinc. The primary zinc acquisition system of the pathogen is the Adc/Lmb ABC permease, which is essential for viability in zinc-restricted environments.

Inductors and regulatory properties of the genomic island-associated fru metabolic operon of Streptococcus agalactiae.

The fru metabolic operon of Streptococcus agalactiae encodes the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) enzyme II complex Fru (EIIB , EIIA , and EIIC ); Fru R, a transcriptional activator with PTS regulatory domains (PRDs); a d-allulose-6-phosphate 3-epimerase; a transaldolase; and a transketolase. We showed that the transcription of fru is induced during the stationary phase of growth in complex media and during incubation in human cerebrospinal or amniotic fluids. d-allose and d-ribose are environmental signals governing this induction.

The Adc/Lmb System Mediates Zinc Acquisition in Streptococcus agalactiae and Contributes to Bacterial Growth and Survival.

Unlabelled: The Lmb protein of Streptococcus agalactiae is described as an adhesin that binds laminin, a component of the human extracellular matrix. In this study, we revealed a new role for this protein in zinc uptake. We also identified two Lmb homologs, AdcA and AdcAII, redundant binding proteins that combine with the AdcCB translocon to form a zinc-ABC transporter.

An homolog of the Frz Phosphoenolpyruvate:carbohydrate phosphoTransferase System of extraintestinal pathogenic Escherichia coli is encoded on a genomic island in specific lineages of Streptococcus agalactiae.

We identified a Streptococcus agalactiae metabolic region (fru2) coding for a Phosphoenolpyruvate:carbohydrate phosphoTransferase System (PTS) homologous to the Frz system of extraintestinal pathogenic Escherichia coli strains. The Frz system is involved in environmental sensing and regulation of the expression of adaptation and virulence genes in E. coli.

[The relationship between aneurysmal subarachnoid hemorrhage and meteorological parameters based on a series of 236 French patients].

Subarachnoid hemorrhage (SAH) is a sudden and potentially severe event with mortality rates ranging between 24 and 30 % depending on the initial clinical condition. Studies have attempted to assess the possible influence of meteorological parameters on the occurrence of SAH. However, this idea remains very controversial and the results vary widely from one study to another.

COV2HTML: a visualization and analysis tool of bacterial next generation sequencing (NGS) data for postgenomics life scientists.

COV2HTML is an interactive web interface, which is addressed to biologists, and allows performing both coverage visualization and analysis of NGS alignments performed on prokaryotic organisms (bacteria and phages). It combines two processes: a tool that converts the huge NGS mapping or coverage files into light specific coverage files containing information on genetic elements; and a visualization interface allowing a real-time analysis of data with optional integration of statistical results. To demonstrate the scope of COV2HTML, the program was tested with data from two published studies.

Characterization of a French series of female cases of mesothelioma.

Background: More than 80% of mesothelioma cases in men are attributable to occupational asbestos exposure compared to only 40% in women. The objective of the study was to characterize a series of female pleural mesotheliomas according to known and suspected risk factors.

Methods: From the exhaustive recording of 318 female mesothelioma cases in the French National Mesothelioma Surveillance Program between 1998 and 2009, multiple correspondence analysis and hybrid clustering were performed to characterize these cases according to expert assessed occupational and non-occupational exposure to asbestos and man-made vitreous fibers, X-ray exposure, and history of cancer and non-malignant respiratory diseases.

Global transcriptional control by glucose and carbon regulator CcpA in Clostridium difficile.

The catabolite control protein CcpA is a pleiotropic regulator that mediates the global transcriptional response to rapidly catabolizable carbohydrates, like glucose in Gram-positive bacteria. By whole transcriptome analyses, we characterized glucose-dependent and CcpA-dependent gene regulation in Clostridium difficile. About 18% of all C.

Characterization of Acp, a peptidoglycan hydrolase of Clostridium perfringens with N-acetylglucosaminidase activity that is implicated in cell separation and stress-induced autolysis.

This work reports the characterization of the first known peptidoglycan hydrolase (Acp) produced mainly during vegetative growth of Clostridium perfringens. Acp has a modular structure with three domains: a signal peptide domain, an N-terminal domain with repeated sequences, and a C-terminal catalytic domain. The purified recombinant catalytic domain of Acp displayed lytic activity on the cell walls of several Gram-positive bacterial species.

Characterization of AtlL, a bifunctional autolysin of Staphylococcus lugdunensis with N-acetylglucosaminidase and N-acetylmuramoyl-l-alanine amidase activities.

The nucleotide sequence of atlL, a gene encoding a putative Staphylococcus lugdunensis peptidoglycan hydrolase, was determined using degenerate consensus PCR and genome walking. This 3837-bp gene encodes a protein, AtlL, that appears as a putative bifunctional autolysin with a 29-amino acid putative signal peptide and two enzymatic putative centres (N-acetylmuramoyl-l-alanine amidase and N-acetylglucosaminidase) interconnected with three imperfect repeated sequences displaying glycine-tryptophan motifs. In order to determine whether both lytic domains were functional, and verify their exact enzymatic activities, gene fragments harbouring both putative domains, AM (N-acetylmuramoyl-l-alanine amidase enzymatic centre plus two repeated sequences) and GL (N-acetylglucosaminidase enzymatic centre plus one repeated sequence), were isolated, subcloned, and expressed in Escherichia coli.

Acd, a peptidoglycan hydrolase of Clostridium difficile with N-acetylglucosaminidase activity.

A gene encoding a putative peptidoglycan hydrolase was identified by sequence similarity searching in the Clostridium difficile 630 genome sequence, and the corresponding protein, named Acd (autolysin of C. difficile) was expressed in Escherichia coli. The deduced amino acid sequence of Acd shows a modular structure with two main domains: an N-terminal domain exhibiting repeated sequences and a C-terminal catalytic domain.