Employs Multiple Mechanisms of Salivary Mucin Binding That Differ Between Strains.

is an oral commensal and opportunistic pathogen that can enter the bloodstream and cause bacteremia and infective endocarditis. Here, we investigated the mechanisms of binding to oral mucins using clinical isolates, isogenic mutants and glycoconjugates. bound to both MUC5B and MUC7, with a higher level of binding to MUC7.

pneumolysin and neuraminidase A convert high-density lipoproteins into pro-atherogenic particles.

High-density lipoproteins (HDLs) are a group of different subpopulations of sialylated particles that have an essential role in the reverse cholesterol transport (RCT) pathway. Importantly, changes in the protein and lipid composition of HDLs may lead to the formation of particles with reduced atheroprotective properties. Here, we show that pneumolysin (PLY) and neuraminidase A (NanA) impair HDL function by causing chemical and structural modifications of HDLs.

CesL Regulates Type III Secretion Substrate Specificity of the Enteropathogenic Injectisome.

The type III secretion system (T3SS) is a complex molecular device used by several pathogenic bacteria to translocate effector proteins directly into eukaryotic host cells. One remarkable feature of the T3SS is its ability to secrete different categories of proteins in a hierarchical manner, to ensure proper assembly and timely delivery of effectors into target cells. In enteropathogenic , the substrate specificity switch from translocator to effector secretion is regulated by a gatekeeper complex composed of SepL, SepD, and CesL proteins.

A novel sialic acid-binding adhesin present in multiple species contributes to the pathogenesis of Infective endocarditis.

Bacterial binding to platelets is a key step in the development of infective endocarditis (IE). Sialic acid, a common terminal carbohydrate on host glycans, is the major receptor for streptococci on platelets. So far, all defined interactions between streptococci and sialic acid on platelets are mediated by serine-rich repeat proteins (SRRPs).

Streptococcus oralis subsp. Produces Monolateral Serine-Rich Repeat Protein Fibrils, One of Which Contributes to Saliva Binding via Sialic Acid.

Our studies reveal that the oral colonizer and cause of infective endocarditis subsp. displays a striking monolateral distribution of surface fibrils. Furthermore, our data suggest that these fibrils impact the structure of adherent bacterial chains.

Novel insights into the mechanism of SepL-mediated control of effector secretion in enteropathogenic Escherichia coli.

Type three secretion systems (T3SSs) are virulence determinants employed by several pathogenic bacteria as molecular syringes to inject effector proteins into host cells. Diarrhea-producing enteropathogenic Escherichia coli (EPEC) uses a T3SS to colonize the intestinal tract. T3S is a highly coordinated process that ensures hierarchical delivery of three classes of substrates: early (inner rod and needle subunits), middle (translocators), and late (effectors).

Identification of Aminopeptidase-N2 as a Cry2Ab binding protein in Manduca sexta.

Bacillus thuringiensis Cry2Ab toxin has been used in combination with Cry1Ac for resistance management on the Bt-cotton that is widely planted worldwide. However, little is known regarding Cry2Ab mode of action. Particularly, there is a gap of knowledge on the identification of insect midgut proteins that bind Cry2Ab and mediate toxicity.

Type Three Secretion System in Attaching and Effacing Pathogens.

Enteropathogenic and enterohemorrhagic are diarrheagenic bacterial human pathogens that cause severe gastroenteritis. These enteric pathotypes, together with the mouse pathogen , belong to the family of attaching and effacing pathogens that form a distinctive histological lesion in the intestinal epithelium. The virulence of these bacteria depends on a type III secretion system (T3SS), which mediates the translocation of effector proteins from the bacterial cytosol into the infected cells.

Functional Characterization of EscK (Orf4), a Sorting Platform Component of the Enteropathogenic Escherichia coli Injectisome.

Unlabelled: The type III secretion system (T3SS) is a supramolecular machine used by many bacterial pathogens to translocate effector proteins directly into the eukaryotic host cell cytoplasm. Enteropathogenic Escherichia coli (EPEC) is an important cause of infantile diarrheal disease in underdeveloped countries. EPEC virulence relies on a T3SS encoded within a chromosomal pathogenicity island known as the locus of enterocyte effacement (LEE).