Background There is growing evidence to implicate Staphylococcus aureus ( S. aureus) in the pathogenesis of recalcitrant chronic rhinosinusitis (CRS). Our group has demonstrated the ability of S. aureus to internalise within mast cells in nasal polyps and this may mediate disease recalcitrance. We investigated carriage of virulence genes in CRS-related S. aureus strains and its influence on the bacteria’s ability to localise and survive intracellularly. Methods S. aureus strains isolated from non-CRS controls (n=5), CRSsNP (n=4) and CRSwNP patients (n=4) were sequenced using short read paired sequencing and interrogated for carriage of virulence genes. A representative control and CRSwNP isolate were tested for intracellular survival in the LAD2 mast cell line to investigate phenotypic differences. Results Fifty percent of the CRSwNP group had deletion of the hld gene which may promote small colony variant formation or reduced enterotoxin production, and seventy-five percent expressed virulence genes associated with invasive disease. The CRSwNP isolate had a superior ability to localise intracellularly at 6 and 9 hours and showed a higher burden of S. aureus colony forming units at 24 hours. Conclusions When compared to non-CRS controls, CRS-related S. aureus strains demonstrate increased carriage of virulence genes. This appears to facilitate intracellular localisation of the bacteria conferring a survival advantage and enhancing pathogenicity. The latter may be partly due to a reduction in enterotoxin production and the acquisition of serine proteases splA and B and leukocidins E/D genes. This pathogenic S. aureus phenotype may manifest clinically with disease recalcitrance and refractoriness to antibiotics.

Objective To determine the impact of the COVID-19 pandemic on acute admissions and inpatient activity at a tertiary referral centre. Design Retrospective review of coding-based inpatient electronic records. Setting An otolaryngology and head and neck surgery department at a UK major trauma and tertiary referral centre. Participants Otolaryngology patients admitted as an emergency over a period of 12 months pre-COVID19 (01/04/2019-31/03/2020) and 10 months post-COVID19 (01/04/2020-23/01/2021). Main outcome measures Baseline characteristics, admission rates, length of stay (LoS), overall mortality and 30-day mortality. Results 1844 records were reviewed; (1293 pre-COVID19, 551 post-COVID19). Admissions across all age groups were reduced, with an increase in mean age from 40.4 to 47.4 years (p=0.001). LoS remained unchanged (3.74 vs 3.82 days, p=0.251). Epistaxis remained the most common presentation, with an increased LoS compared to the pre-COVID19 cohort. GP referrals reduced from 18.0% to 4.2% (n=233 vs n=23, p<0.001) and ED referrals proportionally increased from 60.9% to 75.3%, n=787 vs n=417, p<0.001). Critical care admissions were higher in the post-COVID19 cohort (OR 1.82 (1.11-2.99) [95% CI], p=0.017). There was no significant difference in overall mortality between groups (n=74, 5.7% vs. n=33, 6.0%; p=0.844). Thirty-day mortality increased from 0.9% (n=12) pre-COVID19 to 2.3% (n=13) post-COVID19 (p=0.03). Conclusions This study demonstrates significant changes and a reduction in acute otolaryngology presentations. Our findings suggest that sicker, frailer patients were admitted during the pandemic. This study highlights important considerations for acute otolaryngology care moving forward after the pandemic.