Blocking bacterial adhesion to host surfaces provides novel potential to control infections. The present study was directed to binding and inhibitory activity of different fresh berries and berry and fruit juices against Neisseria meningitidis . Berries and juices were fractionated according to their molecular size into three fractions. A microtiter well assay for binding of N. meningitidis pili to berry and juice fractions was constructed. In addition, adhesion inhibition to human epithelial cells (HEC-1B) was tested. The active fractions were then subfractionated by employing solid-phase extraction. Subfractions were characterized by RP-HPLC-DAD, and the pili binding was evaluated by using microtiter well binding assay. Binding and inhibitory activity were detected to bilberry, cranberry, lingonberry, and crowberry fractions, which contained anthocyanins or a mixture of proanthocyanidins and flavonols. Thus, the findings identify several previously unknown binding and inhibitory activities and may suggest Vaccinium berries and crowberry as promising sources against meningococcal adherence.

Coaggregation is an interspecies adhesion process, which is essential to the development of dental plaque. This is an in vitro study of the composition of the soluble solids in the berry juice molecular size fractions (<10 kDa, FI; 10–100 kDa, FII; >100 kDa, FIII) derived from apple, bilberry, blackcurrant, cloudberry, crowberry and lingonberry and their ability to inhibit and reverse coaggregation of the pairs of common species in dental plaque: Streptococcus mutans with Fusobacterium nucleatum or Actinomyces naeslundii. Inhibitory and reversal activity was found in the molecular size fractions FII and FIII of bilberry, blackcurrant, crowberry and lingonberry. The active fractions contained higher amounts of polyphenols (5–12% of soluble solids) than those without activity (<2% of soluble solids). Proanthocyanidins dominated in the active lingonberry juice fractions FII and FIII and also small amounts of anthocyanins were detected. Anthocyanins, proanthocyanidins and flavonol glycosides were prevalent in FII and FIII fractions of bilberry, blackcurrant and crowberry juices. Comparable amounts of sugars and titratable acids were present in the latter three berry juice fractions of different size. The results indicate that the high molecular size fractions of lingonberry, bilberry, blackcurrant and crowberry juices have antiaggregation potential on common oral bacteria, the potential being associated with their polyphenolic content. Copyright © 2010 John Wiley & Sons, Ltd.