Digital Public defence: Kjell Arild Danielsen

MD Kjell Arild Danielsen at Institute of Clinical Medicine will be defending the thesis “The role of bacterial biofilms in the pathogenesis of chronic rhinosinusitis” for the degree of PhD (Philosophiae Doctor).

The University of Oslo arranges all public defences digitally this semester, thus the disputation will be held as a video conference over Zoom.

The public defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.

Click here to participate in the public defence

Download Zoom here


Digital Trial Lecture – time and place

See Digital Trial Lecture.

Adjudication committee

  • First opponent: Professor Ann Hermansson, Öron-, näs- och halssjukdomar Lunds Universitet Sverige
  • Second opponent: Professor Pär Stjärne, Klinisk vetenskap, intervention och teknik, Karolinska Institutet, Sverige
  • Third member and chair of the evaluation committee: Førsteamanuensis G.Cecilie Alfsen, University of Oslo

Chair of the Defence

Professor Emeritus Tom Øresland, University of Oslo

Principal Supervisor

Associate Medical Director Biogen Espen  Burum-Auensen, Universitetet i Oslo


Patients with chronic rhinosinusitis have decreased quality of life. The prevalence of this disease is estimated at above ten percent in some studies. This poses a major socioeconomic challenge.

The pathogenesis is still poorly understood. The fact that ordinary bacterial tests are often negative has led many researchers to conclude that bacteria play no part in the pathogenesis.

Within the microbiological community the importance of bacteria in chronic infectious disease is increasingly recognized. Bacteria spend more than 99 percent of their time in the colony form as biofilms. Biofilms are hard to culture on growth mediums and seldom “show up” on normal bacterial tests. Antibiotics are less effective against biofilms than the free planktonic form which represents the other major bacterial state.

The aims of the thesis were to investigate the occurrence of biofilms in patients with sinusitis undergoing surgery compared to controls. Per operative biopsies where harvested and underwent confocal laser scanning microscopy to determine the presence of biofilms.

This microscope allows 3-dimensional examination of the biopsies and is considered the gold standard for determining biofilm.

Biofilms where significantly more prevalent in sinusitis patients compared to controls (55/61 vs 14/25, p<0.001, chi-square 13.1) and interestingly also a significantly higher prevalence in sinusitis patients with nasal polyps compared to sinusitis patients without polyps (33/34 vs 22/27, p = 0.042). Furthermore the prevalence of biofilms in the start of the ethmoid sinus cells (ethmoid bulla) was significantly higher than on the front of the middle turbinate (43/54 vs 31/50, p = 0.047).

These findings are comparable to international studies and strongly implies a role for bacterial biofilms in the pathogenesis of chronic sinusitis.

Additional information

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Published May 27, 2020 11:12 AM - Last modified June 15, 2020 9:12 AM