Intercellular communications in multispecies oral microbial communities

Abstract

The oral cavity contains more than 700 microbial species that are engaged in extensive cell–cell interactions. These interactions contribute to the formation of highly structured multispecies communities, allow them to perform physiological functions, and induce synergistic pathogenesis. Co-adhesion between oral microbial species influences their colonization of oral cavity and effectuates, to a large extent, the temporal and spatial formation of highly organized polymicrobial community architecture. Individual species also compete and collaborate with other neighboring species through metabolic interactions, which not only modify the local microenvironment such as pH and the amount of oxygen, making it more suitable for the growth of other species, but also provide a metabolic framework for the participating microorganisms by maximizing their potential to extract energy from limited substrates. Direct physical contact of bacterial species with its neighboring co-habitants within microbial community could initiate signaling cascade and achieve modulation of gene expression in accordance with different species it is in contact with. In addition to communication through cell–cell contact, quorum sensing (QS) mediated by small signaling molecules such as competence-stimulating peptides (CSPs) and autoinducer-2 (AI-2), plays essential roles in bacterial physiology and ecology. This review will summarize the evidence that oral microbes participate in intercellular communications with co-inhabitants through cell contact-dependent physical interactions, metabolic interdependencies, as well as coordinative signaling systems to establish and maintain balanced microbial communities.

Association of oral streptococci community dynamics with severe early childhood caries as assessed by PCR-denaturing gradient gel electrophoresis targeting the rnpB gene

“…According to these findings and the previous studies, we infer that the decline in streptococcal diversity in S-ECC plaques is possible because of shifts in the balance of the resident plaque microbiota (Jiang et al, 2011;Li et al, 2007;Ling et al, 2010). Bacterial species present in the dental biofilm communities have cooperative or competitive interactions with other members (Guo et al, 2014). Because of their genetic similarity, the oral streptococci have similar metabolic activities, and multiple species can compete for the ecological niche on the saliva-coated tooth surface.…”

The chemistry of negotiation: Rhythmic, glycan-driven acidification in a symbiotic conversation

“…pH homeostasis is emerging as a factor that regulates not only the phylogenetic composition of complex microbial communities in the oral cavity and gut, but also immune maturation and host health (45)(46)(47). In the squid-vibrio symbiosis, the diel acidification of the host tissue environment by bacterial metabolism is likely to affect activities beyond the bioluminescence phenotype of this association.…”

Oral Helicobacter pylori: Interactions with host and microbial flora of the oral cavity

“…The number of bacterial species localized in this region is estimated at 600-800. 8 In addition to the enormous diversity of microorganisms, the oral ecosystem is characterized by succession, microbial composition variations and changes in conditions within the different morphological regions of the oral cavity. 9 For this reason, oral biofilm is a very dynamic environment modified by availability and type of nutrient substances, pH, microbial toxic metabolite concentration, host immune response and shear forces.…”