Synergy in biofilm formation between Fusobacterium nucleatum and Prevotella species

Abstract

Japan Running title: F. nucleatum-Prevotella species CoaggregationThe aim of this study was to characterize the role of coaggregation between Fusobacterium nucleatum and Prevotella species in biofilm formation. Materials and Methods:ATCC and clinically isolated strains of F. nucleatum, P.intermedia and P. nigrescens were subjected. Coaggregation between these species was determined by visual assay. Biofilm formation was assessed by crystal violet staining. Effect of co-culture of F. nucleatum with Prevotella species was evaluated. Enhancement of biofilm formation via soluble factor was also examined by addition of culture supernatant and a two-compartment separated co-culture system. Production of autoinducer-2 (AI-2) by the tested organisms was evaluated using Vibrio harveyi BB170.Results: Cells of all F. nucleatum strains coaggregated with P. intermedia or P.nigrescens. Addition of EDTA or L-lysine inhibited coaggregation, the other sugars and amino acids tested did not. Coaggregation disappeared after heating of P. intermedia and P. nigrescens cells, but not after heating of F. nucleatum cells. Proteinase K treatment of P. nigrescens cells affected coaggregation with F. nucleatum, but no significant effect was observed with the treatment of cells of P. intermedia or F. nucleatum. The quantities of biofilm formation by strains of F. nucleatum, P. intermedia and P. nigrescens varied.Co-culture of F. nucleatum ATCC 25586 with P. intermedia or P. nigrescens strains increased biofilm formation than by the single culture (p<0.05).Production levels of AI-2 in strains of F. nucleatum, P. intermedia and P.3 nigrescens varied. Addition of culture supernatant of P. intermedia or P.nigrescens did not enhance biofilm formation by F. nucleatum, and no biofilm formation enhancement by F. nucleatum was observed by the two-compartment co-culture system. Conclusion:These findings indicate that physical contact by coaggregation of F.nucleatum strains with P. intermedia or P. nigrescens is the key factor in the formation of biofilm by these strains, rather than the AI-2 signaling molecule. 4 IntroductionDental plaque, a multispecies biofilm, is organized on the tooth surfaces and periodontal tissues of the human oral cavity (1). More than 500 taxa of bacteria have been identified in the human oral cavity (2), and an increase in specific anaerobic, Gram-negative bacteria in the biofilm is involved in the progression of periodontal disease (3). Bacterial gene expression in the biofilm is regulated by quorum sensing according to increase in cell density (1). After incorporation into the biofilm, microorganisms become resistant not only to host defense mechanisms, but also antimicrobial agents. Moreover, this change has been suggested to be involved in the persistence of infection by such microorganisms in the subgingival crevice (4).In dental plaque biofilm formation, early colonizers, including streptococci, Coaggregation assayVisual assay of coaggregation of F. nucleatum with P. intermedia or P. leaving a water-clear supernatant...

Anaerobes and Bacterial Vaginosis in Pregnancy: Virulence Factors Contributing to Vaginal Colonisation

“…Other species such as Fusobacterium which also do not adhere well to vaginal epithelial cells [44], are able to facilitate co-aggregation between species such as Prevotella [103] and Bifidobacterium [104] in polymicrobial infections [105,106] by acting as a bridge between early and late colonisers in biofilm formation [107,108,109] and by supporting the growth of obligate anaerobes such as Porphyromonas , [110,111] in aerated and carbon dioxide depleted environments [110,111,112]. By adhering to other vaginal microbes [113], F. nucleatum is able to mask the surface components that are recognized by H 2 O 2 -producing lactobacilli and prevent detection by antagonistic microflora thus allowing for its integration into the developing vaginal microbial community associated with BV [114].…”

Dentilisin involvement in coaggregation between Treponema denticola and Tannerella forsythia

“…T. denticola and T. forsythia have fastidious growth requirements for culture [6,11]. Several bacterial pairs were reptorted to required cell to cell contact for enhancement of biofilm formation [41,42]. Taken together with these reports, the coaggregation reaction between T. denticola and T. forsythia may work for adhesion and colonization to dental plaque and involve the increase of T. denticola or T. forsythia in dental plaque.…”

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“…The synergy biofilm formation by Prevotella spp. and other bacteria such as Fusobacterium nucleatum (Okuda et al, 2012) and Porphyromonas (Henry et al, 1996) has been previously reported.…”