Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.
Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Professor Ann Hermansson, Lund University, Sweden
- Second opponent: Associate Professor Teemu Kinnari, Helsinki University Hospital,
- Third member and chair of the evaluation committee: Professor Knut Magne Augestad, University of Oslo
Chair of the Defence
Associate Professor Johannes Kurt Schultz, University of Oslo
Principal Supervisor
Professor Juha Tapio Silvola, University of Oslo
Summary
Bacterial cells can exist in a planktonic state or as part of a larger biofilm community. Biofilms are clusters of bacteria offering physical protection for the bacterial cells towards the host defense system and antibiotics.
The aims of the thesis were to assess the effect of different antimicrobial treatments on staphylococci living in biofilm, both in vivo and in vitro. In Paper 1, the antibacterial efficacy of Lugol’s solution, acetic acid, and boric acid were studied. In Paper 2, the antimicrobial efficacy of Bioactive glass (BAG) on S. aureus in biofilm was studied. In addition, we assessed whether supernatant fluid primed from BAG retained its antibacterial capacity. Both Paper 1 and Paper 2 were in vitro studies. In Paper 3, the antibacterial efficacy of Lugol’s solution and Gentian violet against MRSA biofilm in a murine wound model were studied.
In Paper 1 and Paper 2, three methods were used to evaluate the antimicrobial effect on S. aureus in biofilm: Biofilm-oriented antiseptic test, Bactericidal biofilm test, and Confocal laser scanning microscopy combined with LIVE/DEAD staining. In Paper 3, the antimicrobial effect on the biofilm bacteria was evaluated by measuring bioluminescence from luciferase-tagged MRSA in wounds.
In this thesis, we showed Lugol’s solution to effectively eradicate S. aureus in biofilm in vitro and MRSA biofilm in vivo. Gentian violet effectively eradicated MRSA biofilm in vivo. Direct exposure to BAG granules and primed supernatant fluid effectively eradicated S. aureus in biofilm in vitro.
These findings are important since effective non-antibiotic treatments for S. aureus biofilm infections can be a supplement to, and thereby save the use of antibiotics. In addition, the low cost of the antimicrobials studied is important in a global perspective to ensure more equal access to healthcare.
Additional information
Contact the research support staff.