School of Infection & Immunity

Megan Smith-Cerdan

Title: The impact of mucin and the nasal microbiome of Staphylococcus aureus nasal colonisation and host-pathogen interactions.

Synopsis: 

Staphylococcus aureus is a major human pathogen capable of asymptomatic nasal colonisation in 30-50% of the population, a primary risk factor for infection development. Nasal epithelial cell attachment is well characterised, but the impact of the mucus layer has not yet been elucidated. Within this nutrient-limited niche, mucus acts as the main carbon source accessible through a cocktail of mucolytic enzymes- many of which S. aureus lacks. In the gut, cross-feeding of mucin degradation products between members of the microbiome supports the growth of those lacking the complete enzymatic repertoire. A recent study also demonstrated that S. aureus proliferation was enhanced when the growth of mucolytic bacteria was promoted by anaerobic enrichment of mucus samples from chronic rhinosinusitis patients. However, the species involved in this remain undefined. This research utilises agar-based mucin degradation assays and co-culture cross-feeding assays to investigate the potential for mucin cross-feeding between S. aureus and members of the nasal microbiome.

Bio: 

Megan completed her MBiolSci in Microbiology at the University of Sheffield in 2022. Her master's research focused on antimicrobial resistance and re-sensitising Streptococcus pnuemoniae to beta-lactam antibiotics used in clinic. She is currently a 2nd-year PhD student in Dr. Justine Rudkin’s lab, where her PhD work broadly focuses on the impact of mucin and the nasal microbiome on Staphylococcus aureus nasal colonisation and host-pathogen interactions.

First published: 19 August 2025

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