Modern Plasma Medicine and Orthopaedic Surgery: A Brief History and Outlook.

Modern plasma medicine is a field of medical research combining plasma physics, life sciences, and clinical medicine. It aims to achieve direct application of physical plasma on or in the human body for therapeutic purposes. In medical contexts, the term plasma denotes the liquid component of blood, while in the physical sciences, it refers to ionized gas-also known as the fourth state of matter alongside solid, liquid, and gas.

The mononuclear phagocyte system obscures the accurate diagnosis of infected joint replacements.

Introduction: Diagnosing infected joint replacements relies heavily on assessing the neutrophil response to bacteria. Bacteria form biofilms on joint replacements. Biofilms are sessile bacterial communities encased in a protective extracellular matrix, making them notoriously difficult to culture, remarkably tolerant to antibiotics, and able to evade phagocytosis.

Detecting contamination events during robotic total joint arthroplasty.

Background: Robot-assisted total joint arthroplasty (robotic-TJA) has become more widespread over the last 20 years due to higher patient satisfaction and reduced complications. However, robotic TJA may have longer operative times and increased operating room traffic, which are known risk factors for contamination events. Contamination of surgical instruments may be contact- or airborne-related with documented scalpel blade contamination rates up to 9%.

Host and microbial characteristics associated with recurrent prosthetic joint infections.

Approximately 20% of patients after resection arthroplasty and antibiotic spacer placement for prosthetic joint infection develop repeat infections, requiring an additional antibiotic spacer before definitive reimplantation. The host and bacterial characteristics associated with the development of recurrent infection is poorly understood. A case-control study was conducted for 106 patients with intention to treat by two-stage revision arthroplasty for prosthetic joint infection at a single institution between 2009 and 2020.

Immune checkpoint upregulation in periprosthetic joint infection.

Periprosthetic joint infections (PJI) induce an immunosuppressive cytokine profile through an unknown mechanism. Immune checkpoints, like programmed cell death 1 (PD-1) and its ligand (PD-L1), initiate innate immunosuppressive pathways essential for self-tolerance. Several malignancies and chronic infections co-opt these pathways to derive a survival advantage.

The Safety and Toxicity of Phage Therapy: A Review of Animal and Clinical Studies.

Increasing rates of infection by antibiotic resistant bacteria have led to a resurgence of interest in bacteriophage (phage) therapy. Several phage therapy studies in animals and humans have been completed over the last two decades. We conducted a systematic review of safety and toxicity data associated with phage therapy in both animals and humans reported in English language publications from 2008-2021.

Tolerant Small-colony Variants Form Prior to Resistance Within a Staphylococcus aureus Biofilm Based on Antibiotic Selective Pressure.

Background: The treatment of periprosthetic joint infection (PJI) is focused on the surgical or chemical removal of biofilm. Antibiotics in isolation are typically ineffective against PJI. Bacteria survive after antibiotic administration because of antibiotic tolerance, resistance, and persistence that arise in the resident bacteria of a biofilm.

The Rationale for Using Bacteriophage to Treat and Prevent Periprosthetic Joint Infections.

Prosthetic joint infection (PJI) is a devastating complication after a joint replacement. PJI and its treatment have a high monetary cost, morbidity, and mortality. The lack of success treating PJI with conventional antibiotics alone is related to the presence of bacterial biofilm on medical implants.

A Delayed Inoculation Model of Chronic Pseudomonas aeruginosa Wound Infection.

Pseudomonas aeruginosa (P. aeruginosa) is a major nosocomial pathogen of increasing relevance to human health and disease, particularly in the setting of chronic wound infections in diabetic and hospitalized patients. There is an urgent need for chronic infection models to aid in the investigation of wound pathogenesis and the development of new therapies against this pathogen.

The Immune Response to Chronic Wound Infection in Immunocompetent Mice.

Our goal was to develop a chronic wound model in mice that avoids implantation of foreign material or impaired immunity and to use this to characterize the local and systemic immune response associated with infection. We generated bilateral full-thickness dermal wounds in healthy 10-12-week-old C57Bl6 mice. We waited 24 h to inoculate the developing wound eschar at these sites.

Bacteriophage trigger antiviral immunity and prevent clearance of bacterial infection.

Bacteriophage are abundant at sites of bacterial infection, but their effects on mammalian hosts are unclear. We have identified pathogenic roles for filamentous Pf bacteriophage produced by () in suppression of immunity against bacterial infection. Pf promote wound infection in mice and are associated with chronic human wound infections.

Effect of trabecular metal on the elution of gentamicin from Palacos cement.

Periprosthetic joint infections continues to be a common complication in total joint arthroplasty, resulting in significant morbidity, mortality, and additional cost. Trabecular metal implants with an internal cemented interface may be customizable drug delivery devices with an ingrowth interface. Thirty-six acetabular implants were assembled in vitro, half with a trabecular metal shell and half without.

Periprosthetic bacterial biofilm and quorum sensing.

Periprosthetic joint infection (PJI) is a common complication after total joint arthroplasty leading to severe morbidity and mortality. With an aging population and increasing prevalence of total joint replacement procedures, the burden of PJI will be felt not only by individual patients, but in increased healthcare costs. Current treatment of PJI is inadequate resulting in incredibly high failure rates.

Bithionol blocks pathogenicity of bacterial toxins, ricin, and Zika virus.

Diverse pathogenic agents often utilize overlapping host networks, and hub proteins within these networks represent attractive targets for broad-spectrum drugs. Using bacterial toxins, we describe a new approach for discovering broad-spectrum therapies capable of inhibiting host proteins that mediate multiple pathogenic pathways. This approach can be widely used, as it combines genetic-based target identification with cell survival-based and protein function-based multiplex drug screens, and concurrently discovers therapeutic compounds and their protein targets.

Pf4 bacteriophage produced by Pseudomonas aeruginosa inhibits Aspergillus fumigatus metabolism via iron sequestration.

Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) are major human pathogens known to interact in a variety of disease settings, including airway infections in cystic fibrosis. We recently reported that clinical CF isolates of Pa inhibit the formation and growth of Af biofilms. Here, we report that the bacteriophage Pf4, produced by Pa, can inhibit the metabolic activity of Af biofilms.

Ribonuclease E modulation of the bacterial SOS response.

Plants, animals, bacteria, and Archaea all have evolved mechanisms to cope with environmental or cellular stress. Bacterial cells respond to the stress of DNA damage by activation of the SOS response, the canonical RecA/LexA-dependent signal transduction pathway that transcriptionally derepresses a multiplicity of genes-leading to transient arrest of cell division and initiation of DNA repair. Here we report the previously unsuspected role of E.

Tandem repeats in a new toxin gene from Bacillus thuringiensis and in other cry11-like genes.

A new gene, cry11Bb2 from a field isolate of Bacillus thuringiensis, was cloned for expression in Escherichia coli. The encoded protein, with a deduced molecular mass of 89.5 kDa, exhibits 97 and 79% identities with the overlap regions of Cry11Bb1 from B.

YmdB: a stress-responsive ribonuclease-binding regulator of E. coli RNase III activity.

The broad cellular actions of RNase III family enzymes include ribosomal RNA (rRNA) processing, mRNA decay, and the generation of noncoding microRNAs in both prokaryotes and eukaryotes. Here we report that YmdB, an evolutionarily conserved 18.8-kDa protein of Escherichia coli of previously unknown function, is a regulator of RNase III cleavages.

Variations in the mosquito larvicidal activities of toxins from Bacillus thuringiensis ssp. israelensis.

Comparing activities of purified toxins from Bacillus thuringiensis ssp. israelensis against larvae of seven mosquito species (vectors of tropical diseases) that belong to three genera, gleaned from the literature, disclosed highly significant variations in the levels of LC(50) as well as in the hierarchy of susceptibilities. Similar toxicity comparisons were performed between nine transgenic Gram-negative species, four of which are cyanobacterial, expressing various combinations of cry genes, cyt1Aa and p20, against larvae of four mosquito species as potential agents for biological control.

Larvicidal activities against agricultural pests of transgenic Escherichia coli expressing combinations of four genes from Bacillus thuringiensis.

The genes cry1Ac and cry1Ca from Bacillus thuringiensis subsps. kurstaki HD-73 and aizawai 4J4, respectively, encoding delta-endotoxins against lepidopteran larvae were isolated, cloned and expressed in Escherichia coli, with and without cyt1Aa (encoding cytolytic protein) and p20 (accessory protein) from subsp. israelensis.

Cross-resistance spectra of Culex quinquefasciatus resistant to mosquitocidal toxins of Bacillus thuringiensis towards recombinant Escherichia coli expressing genes from B. thuringiensis ssp. israelensis.

Sixteen Escherichia coli clones were assayed against susceptible and Bacillus thuringiensis-resistant Culex quinquefasciatus larvae. The clones expressed different combinations of four genes from Bacillus thuringiensis ssp. israelensis; three genes encoded mosquitocidal toxins (Cry11Aa, Cry4Aa and Cyt1Aa) and the fourth encoded an accessory protein (P20).

Cyt1Ca from Bacillus thuringiensis subsp. israelensis: production in Escherichia coli and comparison of its biological activities with those of other Cyt-like proteins.

The larvicidal activity of Bacillus thuringiensis subsp. israelensis against dipteran larvae is determined by four major polypeptides of the parasporal crystalline body produced during sporulation. Cyt1Aa shows the lowest toxicity when used alone but is the most synergistic with any of the other proteins.

Partial restoration of antibacterial activity of the protein encoded by a cryptic open reading frame (cyt1Ca) from Bacillus thuringiensis subsp. israelensis by site-directed mutagenesis.

Insecticidal crystal proteins of Bacillus thuringiensis belong to two unrelated toxin families: receptor-specific Cry toxins against insects and Cyt toxins that lyse a broad range of cells, including bacteria, via direct binding to phospholipids. A new cyt-like open reading frame (cyt1Ca) encoding a 60-kDa protein, has recently been discovered (C. Berry et al.

Compaction of the Escherichia coli nucleoid caused by Cyt1Aa.

Compaction of the Escherichia coli nucleoid in the cell's centre was associated with the loss of colony-forming ability; these effects were caused by induction of Cyt1Aa, the cytotoxic 27 kDa protein from Bacillus thuringiensis subsp. israelensis. Cyt1Aa-affected compaction of the nucleoids was delayed but eventually more intense than compaction caused by chloramphenicol.