18.3. Antiadhesive molecules in milk and berries against respiratory pathogens

Public examination of a doctoral dissertation in the field of pharmaceutical chemistry

Doctoral candidate MSc (Pharm) Marko Toivanen

Time and venue 18.3.2011 at 12 noon, Medistudia Auditorium ML3, Kuopio campus

Bacterial attachment to host mucosal tissues is the essential first step in microbial colonization and pathogenesis. The strategy behind antiadhesive agents is to block the adhesion of pathogen to the host cells. Since this reduces the reservoir of bacteria in the human population, it may diminish the frequency of carriers and ultimately reduce the prevalence of bacterial infections. Thus, antiadhesives hold the potential for preventing infectious diseases. This is important since new methods are needed due to shortcomings of effective vaccines and increasing antibiotic resistance.

In the present study, the binding and inhibitory activity of milk, berries and juices were investigated against meningitis- and respiratory infection-associated bacteria. The binding of Neisseria meningitidis pili to bovine thyroglobulin was clearly inhibited by human milk neutral and bovine milk acidic oligosaccharides in a microtiter well assay. In cell culture experiments and the microtiter well assay, inhibitory and binding activity with N. meningitidis were detected for those bilberry, cranberry, lingonberry, and crowberry fractions which contained anthocyanins or a mixture of proanthocyanidins and flavonols. Streptococcus pneumoniae cells bound most extensively to the low-molecular size fraction of cranberry juice and Streptococcus agalactiae cells to the high-molecular size fraction of cranberry. Hemagglutination induced by Streptococcus suis was most effectively inhibited by the middle-molecular size fraction of cranberry.

In conclusion, it has been possible to identify several previously unknown binding and inhibitory sources which impair bacterial adherence; their activities depend on both the natural component and the bacterial species. These results indicate that neutral human milk oligosaccharides and acidic bovine milk oligosaccharides possess potential value in the development of functional foods or drugs against meningococcal infections and furthermore, berry material, especially from the Vaccinium species, may be able to inhibit the attachment of N. meningitidis, S. pneumoniae, S. agalactiae, and S.

The doctoral dissertation of MSc (Pharm) Marko Toivanen, entitled Antiadhesive molecules in milk and berries against respiratory pathogens will be examined at the Faculty of Health Sciences. The opponent in the public examination will be Docent Kirsi-Marja Oksman-Caldentey, VTT Espoo, and the custos will be Professor Seppo Lapinjoki of the University of Eastern Finland.

Photo available for download at http://www.uef.fi/uef/vaitoskuvat

Contact: MSc (Pharm)Marko Toivanen, tel. 040 355 2962, marko.toivanen@uef.fi

Publishing year: 2011

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