18F-labelled gentiobiose as potential PET-radiotracer for specific bacterial imaging: precursor synthesis, radiolabelling and in vitro evaluation.

Aim: Bacterial infections are a clinical challenge, requiring fast and specific diagnosis to ensure effective treatment. Therefore, this project is dedicated to development of positron emission tomography (PET) radiotracers specifically targeting bacteria. Unlike previously developed bacteria-specific radiotracers, which are successful in detecting Gram-negative bacteria, tracers capable of imaging Gram-positive infections are still lacking.

The Influence of Different Sera on the Anti-Infective Properties of Silver Nitrate in Biopolymer Coatings.

The widespread prevalence of periprosthetic joint infections (PJIs) poses significant challenges in orthopedic surgeries, with pathogens such as being particularly problematic due to their capability to form biofilms on implants. This study investigates the efficacy of an innovative silver nitrate-embedded poly-L-lactide biopolymer coating designed to prevent such infections. The methods involved applying varying concentrations of silver nitrate to in vitro setups and recording the resultant bacterial growth inhibition across different serum environments, including human serum and various animal sera.

A novel radiolabelled salmochelin derivative for bacteria-specific PET imaging: synthesis, radiolabelling and evaluation.

For specific imaging of bacterial infections we aimed at targeting the exclusive bacterial iron transport system siderophore-based radiotracers. synthesis and radiolabeling yielded the salmochelin-based PET radiotracer [Ga]Ga-RMA693, which showed a favourable biodistribution and a bacteria-specific uptake in an animal model of infection.

Shock Wave-Activated Silver-Loaded Biopolymer Implant Coating Eliminates on the Surface and in the Surrounding of Implants.

Bacterial biofilms on foreign surfaces are considered a primary cause of implant-related infections, which are challenging to treat. A new implant coating was developed, containing anti-infective silver within a biocompatible polymer carrier substance. In addition to its passive effect on the implant surface, highly concentrated anti-infective silver can be released as needed via the application of high-energy shock waves.

On-Demand Release of Anti-Infective Silver from a Novel Implant Coating Using High-Energy Focused Shock Waves.

Implant-related infections are a significant concern in orthopedic surgery. A novel anti-infective implant coating made of bioresorbable polymer with silver nitrate was developed. A controlled release of silver ions into the vicinity of the prosthesis can be triggered on-demand by extracorporeal shock waves to effectively combat all clinically relevant microorganisms.

Bacterial Lipoproteins Shift Cellular Metabolism to Glycolysis in Macrophages Causing Bone Erosion.

Belonging to a group of membrane proteins, bacterial lipoproteins (LPPs) are defined by a unique lipid structure at their -terminus providing the anchor in the bacterial cell membrane. In Gram-positive bacteria, LPPs play a key role in host immune activation triggered through a Toll-like receptor 2 (TLR2)-mediated action resulting in macrophage stimulation and subsequent tissue damage demonstrated in experimental models. Yet the physiologic links between LPP activation, cytokine release, and any underlying switches in cellular metabolism remain unclear.

Protein Disulfide Isomerase and Extracellular Adherence Protein Cooperatively Potentiate Staphylococcal Invasion into Endothelial Cells.

Invasion of host cells is an important feature of Staphylococcus aureus. The main internalization pathway involves binding of the bacteria to host cells, e.g.

Neutralization of the Staphylococcus aureus Panton-Valentine leukocidin by African and Caucasian sera.

Background: The prevalence of Staphylococcus aureus isolates carrying the Panton-Valentine leukocidin (PVL) gene is higher in Africa (≈50%) compared to Europe (< 5%). The study aimed to measure anti-PVL-antibodies in Africans and Germans in a multi-center study and to test whether detected antibodies can neutralize the cytotoxic effect of PVL on polymorphonuclear leukocytes (PMNs).

Methods: Sera from asymptomatic Africans (n = 22, Nigeria, Gabon) and Caucasians (n = 22, Germany) were used to quantify antibody titers against PVL and α-hemolysin (in arbitrary units [AU]) by ELISA.

Mechanical and microbiological testing concept for activatable anti-infective biopolymer implant coatings.

An anti-infective bilayer implant coating with selectively activatable properties was developed to prevent biofilm formation and to support the treatment of periprosthetic infection as a local adjunct to current treatment concepts. In a first step, Ti6Al4V discs were coated with a permanent layer of Poly(l-lactide) (PLLA) including silver ions. The PLLA could be optionally released by the application of extracorporeal shock waves.

-An Emerging One Health Pathogen?

The -related complex is formed by the , , , and . Within this complex, is the only species mainly found in African wildlife, but it is rarely detected as a colonizer in humans or as a contaminant of fomites. The few detections in humans are most likely spillover events after contact with wildlife.

Quiescence of Human Monocytes after Affinity Purification: A Novel Method Apt for Monocyte Stimulation Assays.

Several methods to isolate monocytes from whole blood have been previously published, with different advantages and disadvantages. For the purpose of cytokine release assessment upon external stimulation, the use of monocyte preparations consisting of non-activated cells is prerequisite. Affinity-isolated monocyte preparations from peripheral blood mononuclear cells (PBMCs), obtained via positive or negative selection using magnetic beads, released pro-inflammatory cytokines such as TNF-α and IL-6 even without adding external stimuli, hindering any assessment of an effect of bacterial lipoproteins on cell stimulation.

Resolving immune cells with patrolling behaviour by magnetic resonance time-lapse single cell tracking.

Background: Immune cells show distinct motion patterns that change upon inflammatory stimuli. Monocytes patrol the vasculature to screen for pathogens, thereby exerting an early task of innate immunity. Here, we aimed to non-invasively analyse single patrolling monocyte behaviour upon inflammatory stimuli.

More Is Not Always Better-the Double-Headed Role of Fibronectin in Staphylococcus aureus Host Cell Invasion.

While Staphylococcus aureus has classically been considered an extracellular pathogen, these bacteria are also capable of being taken up by host cells, including nonprofessional phagocytes such as endothelial cells, epithelial cells, or osteoblasts. The intracellular S. aureus lifestyle contributes to infection development.

Host-pathogen interactions of clinical isolates to induce infective endocarditis.

To evaluate potential pathomechanisms in the induction of infective endocarditis (IE), 34 () isolates, collected from patients with endocarditis and from healthy individuals were investigated both and isolates were tested for their cytotoxicity, invasion and the association with platelets. Virulence factor expression profiles and cellular response were additionally investigated and tested for correlation with the ability of to induce vegetations on the aortic valves . In an animal model of IE valvular conspicuity was assessed by magnetic resonance imaging at 9.

Genomic analysis of Staphylococcus aureus from the West African Dwarf (WAD) goat in Nigeria.

Background: Staphylococcus aureus can colonize various host species, and human-animal interaction is a significant factor for cross-species transmission. However, data on S. aureus colonization in animals, particularly on ruminants in close contact with humans, is limited.

Conjugated Pt(II) Complexes as Luminescence-Switch-On Reporters Addressing the Microenvironment of Bacterial Biofilms.

In this work, the synthesis, structural and photophysical characterization of six phosphorescent HO-soluble Pt(II) complexes are reported while addressing their emission maxima, photoluminescence quantum yields (), lifetimes (), aggregation tendency, and microenvironment sensitivity as a function of the substitution pattern on the main tridentate luminophore. Different ancillary ligands, namely, a trisulfonated phosphane and maltohexaose-conjugated pyridines (with or without amide bridges), were introduced and evaluated for the realization of switch-on-photoluminescent labels reporting on the microenvironment sensed in biofilms of Gram and Gram models, namely, and . With the aid of confocal luminescence micro(spectro)scopy, we observed that selected complexes specifically interact with the biofilms while leaving planktonic cells unlabeled.

A Narrative Review on the Role of Bacteriuria in Bacteremia.

bacteriuria (SABU) can occur in patients with bacteremia (SAB). However, little is known on the (molecular) pathomechanisms of the renal passage of . This review discusses the epidemiology and pathogenesis of SABU in patients with SAB and identifies knowledge gaps.

An in vitro study on Staphylococcus schweitzeri virulence.

Staphylococcus schweitzeri belongs to the Staphylococcus aureus-related complex and is mainly found in African wildlife; no infections in humans are reported yet. Hence, its medical importance is controversial. The aim of this work was to assess the virulence of S.

Impact of Small Colony Variants on Human Lung Epithelial Cells with Subsequent Influenza Virus Infection.

Human beings are exposed to microorganisms every day. Among those, diverse commensals and potential pathogens including () compose a significant part of the respiratory tract microbiota. Remarkably, bacterial colonization is supposed to affect the outcome of viral respiratory tract infections, including those caused by influenza viruses (IV).

Lipoproteins in Gram-Positive Bacteria: Abundance, Function, Fitness.

When one thinks of the Gram+ cell wall, the peptidoglycan (PG) scaffold in particular comes to mind. However, the cell wall also consists of many other components, for example those that are covalently linked to the PG: the wall teichoic acid and the cell wall proteins tethered by the sortase. In addition, there are completely different molecules that are anchored in the cytoplasmic membrane and span the cell wall.

Isolating Crucial Steps in Induction of Infective Endocarditis With Preclinical Modeling of Host Pathogen Interaction.

Animal models of infective endocarditis (IE), especially in rodents, are commonly used to investigate the underlying pathogenesis, disease progression, potential diagnostic approaches, and therapeutic treatment. All these models are based on surgical interventions, and imply valve trauma by placing a polyurethane catheter at the aortic root. While the influence of endothelial damage and inflammation on the induction of IE has been studied intensively, the role of the catheter, as permanent source of bacteremia, and the interplay with bacterial virulence factors during the formation of IE is poorly understood.

The influenza replication blocking inhibitor LASAG does not sensitize human epithelial cells for bacterial infections.

Severe influenza virus (IV) infections still represent a major challenge to public health. To combat IV infections, vaccines and antiviral compounds are available. However, vaccine efficacies vary with very limited to no protection against newly emerging zoonotic IV introductions.

Aetiology of traveller's diarrhea: A nested case-control study.

Background: Traveller's diarrhea (TD) is the leading cause of morbidity among travelers. Recently, molecular methods have been developed to detect the causative pathogens of TD. The aim of this study was to test a multiplex-PCR approach in patients with TD and asymptomatic controls.