Al-2 of Aggregatibacter actinomycetemcomitans inhibits Candida albicans biofilm formation

作者：Bachtiar Endang W; Bachtiar Boy M; Jarosz Lucja M; Amir Lisa R; Sunarto Hari; Ganin Hadas; Meijler Michael M; Krom Bastiaan P^*

来源：Frontiers in Cellular and Infection Microbiology, 2014, 4: 94.

DOI：10.3389/fcimb.2014.00094

• oral microbiology
• interspecies interaction
• quorum sensing

Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium, and Candida albicans, a polymorphic fungus, are both commensals of the oral cavity but both are opportunistic pathogens that can cause oral diseases. A. actinomycetemcomitans produces a quorum-sensing molecule called autoinducer-2 (Al-2), synthesized by LuxS, that plays an important role in expression of virulence factors, in intra- but also in interspecies communication. The aim of this study was to investigate the role of Al-2 based signaling in the interactions between C. albicans and A. actinomycetemcomitans. A. actinomycetemcomitans adhered to C. albicans and inhibited biofilm formation by means of a molecule that was secreted during growth. C. albicans biofilm formation increased significantly when co-cultured with A. acnnomycetemcomitans luxS, lacking Al-2 production. Addition of wild-type-derived spent medium or synthetic Al-2 to spent medium of the luxS strain, restored inhibition of C. albicans biofilm formation to wild-type levels. Addition of synthetic Al-2 significantly inhibited hypha formation of C. albicans possibly explaining the inhibition of biofilm formation. Al-2 of A. actinomycetemcomitans is synthesized by LuxS, accumulates during growth and inhibits C. albicans hypha- and biofilm formation. Identifying the molecular mechanisms underlying the interaction between bacteria and fungi may provide important insight into the balance within complex oral microbial communities.

• 出版日期2014-7