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Introduction: In chronic rhinosinusitis (CRS), the congestion and blockage of the nose can cause anaerobic conditions within the sinus cavities which may promote the expression of virulence and antibiotic resistance genes in invading pathogens. Pseudomonas aeruginosa is a facultative anaerobic bacteria and causes severe recalcitrant CRS. In this study, we aimed to evaluate the antimicrobial resistance of P. aeruginosa isolates of CRS patients in planktonic and biofilm form grown in aerobic and anaerobic conditions. Methods: P. aeruginosa clinical isolates of CRS patients (n = 25) were grown in planktonic and biofilm form in aerobic and anaerobic conditions. Minimum inhibitory concentrations (MIC) of planktonic forms and minimum biofilm eradication concentrations (MBEC) were determined. Additionally, metabolic activity by fluorescein diacetate assay, biofilm biomass by crystal violet assay and eDNA concentration were assessed in both conditions. Results: P. aeruginosa planktonic cells grown in anaerobic condition exhibited increased gentamicin resistance (p < .01), whereas P. aeruginosa biofilms grown in anaerobic condition displayed significantly increased MBEC values for gentamicin (p < .0001) and levofloxacin (p < .001). The metabolic activity of anaerobic biofilms was significantly higher compared with aerobic biofilms (p < .0001). However, the biofilm biomass of isolates grown in aerobic conditions was higher than anaerobic conditions (p < .5). Conclusion: P. aeruginosa isolates from CRS patients grown in anaerobic conditions showed significantly increased resistance to antibiotics with an increased metabolic activity but decreased biofilm biomass. [ABSTRACT FROM AUTHOR]

Chronic rhinosinusitis (CRS) is an inflammatory condition of the sinonasal mucosa. Despite being a common health issue, the exact cause of CRS is yet to be understood. However, research suggests that Staphylococcus aureus, particularly in its biofilm form, is associated with the disease. This study aimed to investigate the impact of long-term exposure to secreted factors of Staphylococcus aureus biofilm (SABSFs), harvested from clinical isolates of non-CRS carrier and CRS patients, on the nasal mucosa in a rat model. Animals were randomised (n = 5/group) to receive daily intranasal instillations of 40 μL (200 μg/μL) SABSFs for 28 days or vehicle control. The sinonasal samples were analysed through histopathology and transcriptome profiling. The results showed that all three intervention groups displayed significant lymphocytic infiltration (p ≤ 0.05). However, only the SABSFs collected from the CRSwNP patient caused significant mucosal damage, mast cell infiltration, and goblet cell hyperplasia compared to the control. The transcriptomics results indicated that SABSFs significantly enriched multiple inflammatory pathways and showed distinct transcriptional expression differences between the control group and the SABSFs collected from CRS patients (p ≤ 0.05). Additionally, the SABSF challenges induced the expression of IgA and IgG but not IgE. This in vivo study indicates that long-term exposure to SABSFs leads to an inflammatory response in the nasal mucosa with increased severity for S. aureus isolated from a CRSwNP patient. Moreover, exposure to SABSFs does not induce local production of IgE. [ABSTRACT FROM AUTHOR]

Chronic rhinosinusitis (CRS) is characterized by sinonasal mucosal inflammation. Staphylococcus aureus (S. aureus) is associated with severe CRS phenotypes. Different animal models have been proposed to study the association of CRS and S. aureus. However, current animal models are expensive due to the use of large animals, have high barriers to ethics approval, or require invasive surgical intervention, necessitating a need for a model that can overcome these limitations. This study aimed at establishing a reliable and efficient rat lymphoplasmacytic inflammatory model for rhinosinusitis. Sprague Dawley rats received a daily intranasal application of 20 μL of saline, S. aureus CI-182 exoprotein (250 μg/mL), or exoprotein CI-182 in combination with S. aureus clinical isolate (CI-908 or CI-913) 108 colony-forming unit (CFU)/mL. The rats' sinuses were harvested at 1 and 2 weeks post-intervention. The CFU and histopathologic examination of inflammation were evaluated. S. aureus clinical isolates CI-908 or CI-913 in combination with the exoprotein (CI-182) had higher CFUs and caused persistently higher inflammation at both the 1 and 2-week post-intervention compared to the exoprotein and saline group. The observed inflammatory cell type was lymphoplasmacytic. This study provided evidence that the combination of a S. aureus exoprotein with S. aureus induces inflammation that persists for a minimum of two weeks post-intervention. This model is the first known animal model to create the lymphoplasmacytic inflammation subtype seen in CRS patients. This offers a cost-effective, accessible, non-invasive, and easy-to-replicate model to study the causes and treatment of such inflammation. [ABSTRACT FROM AUTHOR]

Chronic rhinosinusitis (CRS) is a disease characterised by the inflammation of the nasal and paranasal cavities. It is a widespread condition with considerable morbidity for patients. Current treatment for chronic rhinosinusitis consists of appropriate medical therapy followed by surgery in medically resistant patients. Although oral steroids are effective, they are associated with significant morbidity, and disease recurrence is common when discontinued. The development of additional steroid sparing therapies is therefore needed. Mesalazine is a commonly used therapeutic in inflammatory bowel disease, which shares a similar disease profile with chronic rhinosinusitis. This exploratory in vitro study aims to investigate whether mesalazine could be repurposed to a nasal wash, which is safe on human nasoepithelial cells, and retains its anti-inflammatory effects. CRS patients' human nasal epithelial cells (HNECs) were collected. HNECs were grown at an air-liquid interface (ALIs) and in a monolayer and challenged with mesalazine or a non-medicated control. Transepithelial electrical resistance, paracellular permeability, and toxicity were measured to assess epithelial integrity and safety. The anti-inflammatory effects of mesalazine on the release of interleukin (IL)-6 and tumour necrosis factor alpha (TNF-α) were analysed using human leukemia monocytic cell line (THP-1). mesalazine did not impact the barrier function of HNEC-ALIs and was not toxic when applied to HNECs or THP-1 cells at concentrations up to 20 mM. mesalazine at 0.5 and 1 mM concentrations significantly inhibited TNF-α release by THP-1 cells. mesalazine effectively decreases TNF-α secretion from THP-1 cells, indicating the possibility of its anti-inflammatory properties. The safety profile of mesalazine at doses up to 20 mM suggests that it is safe when applied topically on HNECs. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is one of the most common pathogens encountered in clinical wound infections. Clinical studies have shown that P. aeruginosa infection results in a larger wound area, inhibiting healing, and a high prevalence of antimicrobial resistance. Hydroxypyridinone-derived iron chelator Deferiprone (Def) and heme analogue Gallium-Protoporphyrin (GaPP) in a chitosan-dextran hydrogel (Chitogel) have previously been demonstrated to be effective against PAO1 and clinical isolates of P. aeruginosa in vitro. Moreover, this combination of these two agents has been shown to improve sinus surgery outcomes by quickly reducing bleeding and preventing adhesions. In this study, the efficacy of Def-GaPP Chitogel was investigated in a P. aeruginosa biofilm-infected wound murine model over 6 days. Two concentrations of Def-GaPP Chitogel were investigated: Def-GaPP high dose (10 mM Def + 500 µg/mL GaPP) and Def-GaPP low dose (5 mM Def + 200 µg/mL GaPP). The high-dose Def-GaPP treatment reduced bacterial burden in vivo from day 2, without delaying wound closure. Additionally, Def-GaPP treatment decreased wound inflammation, as demonstrated by reduced neutrophil infiltration and increased anti-inflammatory M2 macrophage presence within the wound bed to drive wound healing progression. Def-GaPP Chitogel treatment shows promising potential in reducing P. aeruginosa cutaneous infection with positive effects observed in the progression of wound healing. [ABSTRACT FROM AUTHOR]

Chronic rhinosinusitis (CRS) represents chronic inflammation of the sinus mucosa characterised by dysfunction of the sinuses' natural defence mechanisms and induction of different inflammatory pathways ranging from a Th1 to a Th2 predominant polarisation. Recalcitrant CRS is associated with Staphylococcus aureus dominant mucosal biofilms; however, S. aureus colonisation of the sinonasal mucosa has also been observed in healthy individuals challenging the significance of S. aureus in CRS pathogenesis. We aimed to investigate the relationship between CRS key inflammatory markers, S. aureus biofilm properties/virulence genes and the severity of the disease. Tissue samples were collected during endoscopic sinus surgery from the ethmoid sinuses of CRS patients with (CRSwNP) and without (CRSsNP) nasal polyps and controls (n = 59). CD3+ T‐cell subset frequencies and key inflammatory markers of CD4+ helper T cells were determined using FACS analysis. Sinonasal S. aureus clinical isolates were isolated (n = 26), sequenced and grown into biofilm in vitro, followed by determining their properties, including metabolic activity, biomass, colony‐forming units and exoprotein production. Disease severity was assessed using Lund–Mackay radiologic scores, Lund–Kennedy endoscopic scores and SNOT22 quality of life scores. Our results showed that S. aureus biofilm properties and CRS severity scores correlated positively with total CD4+ T‐cell frequencies but looking into CD4+ T‐cell subsets showed an inverse correlation with Th1 and Th17 cell frequencies. CD4+ T‐cell frequencies were higher in patients harbouring lukF.PV‐positive S. aureus while its regulatory and Th17 cell subset frequencies were lower in patients carrying sea− and sarT/U‐positive S. aureus. Recalcitrant CRS is characterised by increased S. aureus biofilm properties in relation to increased total CD4+ helper T‐cell frequencies and reduced frequencies of its Th1, Th17 and regulatory T‐cell subsets. These findings offer insights into the pathophysiology of CRS and could lead to the development of more targeted therapies. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine the safety and efficacy of Chitogel, with and without Deferiprone (Def) and Gallium Protoporphyrin (GaPP), as a promoter of wound healing to improve surgical outcomes after endoscopic sinus susgery. Design: A double‐blinded, randomised control human clinical trial was conducted in patients undergoing ESS as a treatment for chronic rhinosinusitis. Participants underwent functional ESS or FESS with drill out as required and were randomised to receive test product Chitogel, Chitogel in combination with Def or Def‐GaPP versus no packing (control). Setting: Ostial stenosis and persistent inflammation are the main reasons for revision endoscopic sinus surgery (ESS). Post‐operative (PO) dressings can improve PO wound healing and patient outcomes after ESS. Participants: Eighty two patients were included in this study with 79 patients completing the study with 40 undergoing full house FESS and 39 FESS plus frontal drillout. Main Outcome Measures: Patients were followed up at 2, 6 and 12 weeks PO, and outcome scores such as SNOT‐22, VAS and LKS, pre and post‐surgery (12 weeks) were compared. Results: Seventy nine patients completed the study, there was a significant reduction in SNOT‐22 score and improvement of VAS at 12 weeks in patients treated with Chitogel compared to control (p <.05). In those patients, the mean ostium area for the Chitogel and the Chitogel + Def + GaPP groups was higher across all three sinuses compared to the no‐treatment control group, without statistical significance. Sphenoid sinus ostium was significantly more patent in patients treated with Chitogel compared to the control at the 12‐week time point (p <.05). Conclusion: Chitogel as a PO dressing after ESS results in the best patient‐reported symptom scores and objective measurements. The combination of Def and GaPP to Chitogel though proving safe, had no effect on the ostium patency or mucosal healing. [ABSTRACT FROM AUTHOR]

Summary In recent years, there has been an increasing interest in bacteriophages, which has led to growing numbers of bacteriophage genomic sequences becoming available. Consequently, there is a need for a rapid and consistent genomic annotation tool dedicated for bacteriophages. Existing tools either are not designed specifically for bacteriophages or are web- and email-based and require significant manual curation, which makes their integration into bioinformatic pipelines challenging. Pharokka was created to provide a tool that annotates bacteriophage genomes easily, rapidly and consistently with standards compliant outputs. Moreover, Pharokka requires only two lines of code to install and use and takes under 5 min to run for an average 50-kb bacteriophage genome. Availability and implementation Pharokka is implemented in Python and is available as a bioconda package using 'conda install -c bioconda pharokka'. The source code is available on GitHub (https://github.com/gbouras13/pharokka). Pharokka has been tested on Linux-64 and MacOSX machines and on Windows using a Linux Virtual Machine. [ABSTRACT FROM AUTHOR]

The nasal epithelium is an important target for drug delivery to the nose and secondary organs such as the brain via the olfactory bulb. For both topical and brain delivery, the targeting of specific nasal regions such as the olfactory epithelium (brain) is essential, yet challenging. In this study, a numerical model was developed to predict the regional dose as mass per surface area (for an inhaled mass of 2.5 mg), which is the biologically most relevant dose metric for drug delivery in the respiratory system. The role of aerosol diameter (particle diameter: 1 nm to 30 µm) and inhalation flow rate (4, 15 and 30 L/min) in optimal drug delivery to the vestibule, nasal valve, olfactory and nasopharynx is assessed. To obtain the highest doses in the olfactory region, we suggest aerosols with a diameter of 20 µm and a medium inlet air flow rate of 15 L/min. High deposition on the olfactory epithelium was also observed for nanoparticles below 1 nm, as was high residence time (slow flow rate of 4 L/min), but the very low mass of 1 nm nanoparticles is prohibitive for most therapeutic applications. Moreover, high flow rates (30 L/min) and larger micro-aerosols lead to highest doses in the vestibule and nasal valve regions. On the other hand, the highest drug doses in the nasopharynx are observed for nano-aerosol (1 nm) and fine microparticles (1–20 µm) with a relatively weak dependence on flow rate. Furthermore, using the 45 different inhalation scenarios generated by numerical models, different machine learning models with five-fold cross-validation are trained to predict the delivered dose and avoid partial differential equation solvers for future predictions. Random forest and gradient boosting models resulted in R2 scores of 0.89 and 0.96, respectively. The aerosol diameter and region of interest are the most important features affecting delivered dose, with an approximate importance of 42% and 47%, respectively. [ABSTRACT FROM AUTHOR]

Background: Sentinel lymph node biopsy (SLNB) is a staging procedure dependent on accurate mapping of draining lymphatics via tracers. Robot‐assisted SLNB enables access to multiple neck levels with a single incision and intraoperative fluorescence guidance to the SLN. Methods: Lymphatic mapping in swine was done using a magnetic tracer and fluorescent dye, injected into the tongue. MRI preoperatively mapped lymphatic spread of the magnetic tracer. Dissection was performed using a da Vinci Xi robot guided by fluorescence‐imaging of the dye. Results: Robot‐assisted SLNB was successfully performed in all animals (n = 5). A novel MRI protocol differentiated SLNs (n = 6) from lower echelon nodes (n = 11) based on flow progression. Fluorescence imaging provided valuable intraoperative guidance and correlated with magnetic‐positive nodes. Conclusions: This study demonstrates preclinical feasibility of a robot‐assisted approach to SLNB using magnetic and fluorescent tracers in the head and neck, enabling both preoperative mapping and intraoperative guidance. [ABSTRACT FROM AUTHOR]