Identification of a novel sequence type of as the causative agent of pyelonephritis and bloodstream infection.

Introduction: Globally, extra-intestinal pathogenic are one of the predominant causative agents of bacteraemia.

Case Presentation: This case report outlines a presentation of community-acquired pyelonephritis and secondary bloodstream infection in an 81-year-old man. Laboratory investigations revealed that the causative isolate was a multi-drug-resistant of a novel multi-locus sequence type.

Characterization of Escherichia coli bloodstream isolates associated with mortality.

Extra-intestinal pathogenic Escherichia coli (ExPEC) are the predominant cause of Gramnegative bloodstream infections. In this study, 20 E. coli isolates that were the causative agents of bacteraemia and subsequent mortality were characterized.

Bacterial self-defence: how Escherichia coli evades serum killing.

The ability to survive the bactericidal action of serum is advantageous to extraintestinal pathogenic Escherichia coli that gain access to the bloodstream. Evasion of the innate defences present in serum, including complement and antimicrobial peptides, involves multiple factors. Serum resistance mechanisms utilized by E.

Response of extraintestinal pathogenic Escherichia coli to human serum reveals a protective role for Rcs-regulated exopolysaccharide colanic acid.

Extraintestinal Escherichia coli (ExPEC) organisms are the leading cause of Gram-negative bacterial bloodstream infections. These bacteria adapt to survival in the bloodstream through expression of factors involved in scavenging of nutrients and resisting the killing activity of serum. In this study, the transcriptional response of a prototypic ExPEC strain (CFT073) to human serum was investigated.

Iron-regulated surface determinant B (IsdB) promotes Staphylococcus aureus adherence to and internalization by non-phagocytic human cells.

Staphylococcus aureus is a human pathogen that causes invasive and recurring infections. The ability to internalize into and persist within host cells is thought to contribute to infection. Here we report a novel role for the well-characterized iron-regulated surface determinant B (IsdB) protein which we have shown can promote adhesion of 293T, HeLa cells and platelets to immobilized bacteria independently of its ability to bind haemoglobin.

Staphylococcus aureus protein A binds to osteoblasts and triggers signals that weaken bone in osteomyelitis.

Osteomyelitis is a debilitating infectious disease of the bone. It is predominantly caused by S. aureus and is associated with significant morbidity and mortality.

Effect of filaggrin breakdown products on growth of and protein expression by Staphylococcus aureus.

Background: Colonization of the skin by Staphylococcus aureus in individuals with atopic dermatitis exacerbates inflammation. Atopic dermatitis is associated with loss-of-function mutations in the filaggrin (FLG) gene, accompanied by reduced levels of filaggrin breakdown products on the skin.

Objective: To assess the affect of growth in the presence of the filaggrin breakdown products urocanic acid (UCA) and pyrrolidone carboxylic acid (PCA) on fitness of and protein expression by S aureus.

Direct interaction of iron-regulated surface determinant IsdB of Staphylococcus aureus with the GPIIb/IIIa receptor on platelets.

The interaction of bacteria with platelets is implicated in the pathogenesis of endovascular infections, including infective endocarditis, of which Staphylococcus aureus is the leading cause. Several S. aureus surface proteins mediate aggregation of platelets by fibrinogen- or fibronectin-dependent processes, which also requires specific antibodies.

Surface proteins that promote adherence of Staphylococcus aureus to human desquamated nasal epithelial cells.

Background: The natural habitat of Staphylococcus aureus is the moist squamous epithelium in the anterior nares. About 20% of the human population carry S. aureus permanently in their noses and another 60% of individuals are intermittent carriers.

Identification of the Staphylococcus aureus MSCRAMM clumping factor B (ClfB) binding site in the alphaC-domain of human fibrinogen.

Clumping factor B (ClfB) of Staphylococcus aureus binds to cytokeratin 10 and to fibrinogen. In this study the binding site in human fibrinogen was localized to a short region within the C terminus of the Aalpha-chain. ClfB only bound to the Aalpha-chain of fibrinogen in a ligand-affinity blot and in solid-phase assays with purified recombinant fibrinogen chains.

Key role for clumping factor B in Staphylococcus aureus nasal colonization of humans.

Background: Staphylococcus aureus permanently colonizes the vestibulum nasi of one-fifth of the human population, which is a risk factor for autoinfection. The precise mechanisms whereby S. aureus colonizes the nose are still unknown.

Both complement- and fibrinogen-dependent mechanisms contribute to platelet aggregation mediated by Staphylococcus aureus clumping factor B.

Staphylococcus aureus can stimulate activation and aggregation of platelets, which are thought to be factors in the development of infective endocarditis. Previous studies have identified clumping factor A (ClfA) and fibronectin binding proteins A and B (FnBPA and FnBPB) as potent platelet aggregators. These proteins are able to stimulate rapid platelet aggregation by either a fibrinogen- or a fibronectin-dependent process which also requires antibodies specific to each protein.