Staphylococcus aureus internalization in mast cells in nasal polyps: Characterization of interactions and potential mechanisms.

BACKGROUND: Chronic rhinosinusitis (CRS) with nasal polyps is a common chronic condition. The exact cause of nasal polyps remains unknown. Recently, we made the novel observation of intracellular localization of Staphylococcus aureus within mast cells in nasal polyps. OBJECTIVE: This follow-up study aimed to further characterize interactions between S aureus and mast cells in this setting and elucidate potential internalization mechanisms with particular emphasis on the role of staphylococcal enterotoxin B (SEB). METHODS: A prospective study was performed using an explant tissue model with ex vivo inferior turbinate mucosa obtained from patients with chronic rhinosinusitis with nasal polyps (n = 7) and patients without CRS (n = 5). Immunohistochemistry was used to characterize S aureus uptake into mast cells and investigate the effects of SEB on this process. An in vitro cell-culture model was used to investigate mast cell-S aureus interactions by using a combination of fluorescent in situ hybridization, confocal laser scanning microscopy, scanning electron microscopy, transmission electron microscopy, and proliferation assays. RESULTS: S aureus was captured by extracellular traps and entered mast cells through phagocytosis. Proliferating intracellular S aureus led to the expansion and eventual rupture of mast cells, resulting in release of viable S aureus into the extracellular space. The presence of SEB appeared to promote internalization of S aureus into mast cells. CONCLUSION: This study provides new insights into the interactions between S aureus and mast cells, including the internalization process, and demonstrates a prominent role for SEB in promoting uptake of the bacteria into these cells.

Improving otitis externa management in secondary care through a standardised treatment algorithm.

OBJECTIVE: Otitis externa is a common condition managed by junior doctor-led ENT clinics in secondary/tertiary care, but no national guidelines exist for presentations in these settings. The aim of this study was to implement a treatment algorithm to support junior doctors and improve otitis externa management. METHODS: Baseline data were retrospectively collected for 16 weeks. A standardised otitis externa treatment algorithm was then implemented, and 16 weeks of data prospectively gathered. A second improvement cycle was completed thereafter focusing on topical antibiotics and water precaution advice. RESULTS: Overall, 202 cases of otitis externa managed between November 2021 to October 2022 were reviewed. Following the interventions, topical antibiotic prescribing improved (p = 0.01) as well as the provision of water precaution advice (p < 0.01). Junior doctors trended towards reviewing patients more frequently but required less senior support. CONCLUSION: Our treatment algorithm empowers junior doctors to become more independent in their management of otitis externa and improves overall otitis externa treatment.

Independent Prescribing Pharmacists Supporting the Early Discharge of Patients Through Completion of Medical Discharge Summaries.

PURPOSE: Independent prescribing pharmacists are able to independently prescribe medications following additional postgraduate training. This study examined their use in completing medical discharge summaries, normally completed by junior doctors, in order to assess their impact on expedited hospital discharge times. METHODS: In total, 163 patients were studied through a 2-stage audit. The first cycle evaluated junior doctors completing medical discharge summaries (as is normal practice). Three independent prescribing pharmacists were then trained to complete discharge summaries, and a second cycle was completed. RESULTS: Following implementation of independent prescribing pharmacists to complete medical discharge summaries, the time from medical decision to discharge to summary completion dropped significantly (mean of 2:42 hours to 1:35 hours, P < .001). The time from medical decision to discharge to actual hospital discharge also dropped significantly (mean of 5:21 hours to 3:58 hours, P < .01). The number of discharge summary medication errors dropped significantly (P < .05) between audit cycles. CONCLUSION: The introduction of independent prescribing pharmacists to complete medical discharge summaries has significantly reduced the time to summary completion, discharge time, and the number of medication errors. In a time of limited medical resources and bed shortages, the use of allied health professionals to improve service delivery is of paramount importance. This project is the first of its kind within the literature.

Noise Exposure on the London Underground, an Observational Study over a Decade.

OBJECTIVES: There are no hearing protection regulations in place for passengers using public transport, such as the London Underground. In light of this, we sought to examine sound pressure levels experienced by regular users of the London Underground. METHODS: Sound pressure levels (A-weighted decibels: dBA) were taken on moving London Underground carriages between Euston and South Wimbledon on the Northern Line, and between Euston and Vauxhall on the Victoria Line, during 2006 and 2018. In addition, carriage sound pressure levels travelling within Zone 1 of the London Underground were tested in 2019. Three experimental and three technical repeats were undertaken using a hand-held calibrated multi-function sound level meter. RESULTS: Passengers are routinely and consistently subjected to sound pressure levels exceeding 80 dBA, with levels sometimes reaching over 100 dBA. CONCLUSION: This study is unique within the literature, with no published studies outlining exposure levels for London Underground passengers. It provides evidence of elevated noise exposure to passengers, consistently along large stretches of the London Underground, over a prolonged study period (2006-2019). KEY WORDS: Sensorineural hearing losssound pressureexposureLondonundergroundtube. LEVEL OF EVIDENCE: N/A Laryngoscope, 2020.

Reactive oxygen: A novel antimicrobial mechanism for targeting biofilm-associated infection.

Reactive oxygen species (ROS) is a novel therapeutic strategy for topical or local application to wounds, mucosa or internal structures where there may be heavy bacterial bioburden with biofilm and chronic inflammation. Bacterial biofilms are a significant problem in clinical settings owing to their increased tolerance towards conventionally prescribed antibiotics and their propensity for selection of further antibacterial resistance. There is therefore a pressing need for the development of alternative therapeutic strategies that can improve antibiotic efficacy towards biofilms. ROS has been successful in treating chronic wounds and in clearing multidrug-resistant organisms, including methicillin-resistant Staphylococcus aureus (MRSA), and carbapenemase-producing isolates from wounds and vascular line sites. There is significant antifungal activity of ROS against planktonic and biofilm forms. Nebulised ROS has been evaluated in limited subjects to assess reductions in bioburden in chronically colonised respiratory tracts. The antibiofilm activity of ROS could have great implications for the treatment of a variety of persistent respiratory conditions. Use of ROS on internal prosthetic devices shows promise. A variety of novel delivery mechanisms are being developed to apply ROS activity to different anatomical sites.

Use of the lymphocyte count as a diagnostic screen in adults with suspected Epstein-Barr virus infectious mononucleosis.

OBJECTIVES/HYPOTHESIS: To evaluate the predictive diagnostic accuracy of the lymphocyte count in Epstein-Barr virus-related infectious mononucleosis (IM). STUDY DESIGN: Retrospective case note and blood results review within a university-affiliated teaching hospital. METHODS: A retrospective review of 726 patients undergoing full blood count and Monospot testing was undertaken. Monospot testing outcomes were compared with the lymphocyte count, examining for significant statistical correlations. RESULTS: With a lymphocyte count of ≤4 × 10(9) /L, 99% of patients had an associated negative Monospot result (sensitivity of 84% and specificity of 94%). A group subanalysis of the population older than 18 years with a lymphocyte count ≤4 × 10(9) /L revealed that 100% were Monospot negative (sensitivity of 100% and specificity of 97%). A lymphocyte count of ≤4 × 10(9) /L correlated significantly with a negative Monospot result. CONCLUSIONS: A lymphocyte count of ≤4 × 10(9) /L appears to be a highly reliable predictor of a negative Monospot result, particularly in the population aged >18 years. Pediatric patients, and adults with strongly suggestive symptoms and signs of IM, should still undergo Monospot testing. However, in adults with more subtle symptoms and signs, representing the vast majority, Monospot testing should be restricted to those with a lymphocyte count >4 × 10(9) /L. LEVEL OF EVIDENCE: NA