Biofilm Control Strategies in Dental Health - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 305

aciduricity, genetic transformation, and bacteriocin production (Senadheera and
Cvitkovitch 2008 ). CSP is synthesized in the cell and released into the extracellular
medium. When the bacterial density increases, CSP molecules in the external
environment reach a threshold concentration and, as with other two component
systems, the expression profiles of bacteria producing the CSP molecules is mod-
ulated. When used at high concentrations, CSP can actually contribute to cell death
in S. mutans . Analogues of this QS peptide decrease biofilm formation of various
Streptococcus species and can potentially be used to control cariogenic biofilms
(LoVetri and Madhyastha 2010 ).
7 Biological Methods to Control Oral Biofilms
7.1 Vaccination
As antibacterial agents can be rendered ineffective by the development of resistance
in target organisms, it can be difficult to maintain a therapeutic concentration in the
oral cavity and can be toxic to the host. Thus, there is a need to develop alternative
approaches for treatment. Vaccines are proposed to be an effective therapy to
control oral biofilm and target oral pathogens. Although viruses have been impli-
cated in some cases of periodontal disease (Grinde and Olsen 2010 ; Slots 2010 )we
will only focus on the use of vaccines against the bacterial fraction of the oral
biofilm.
An example of a recent vaccine whose strategy is to control oral biofilm rather
than target specific pathogens is a vaccine against the oral bacterium
Fusobacterium nucleatum. As previously mentioned, this organism plays a central
bridging role in the structure of pathogenic periodontal biofilms (Kolenbrander
2000 ; Kolenbrander et al. 2002 ). An antibody generated against the FomA outer
membrane protein of F. nucleatum significantly abrogated bacterial co-aggregation,
biofilm formation, and the production of volatile sulfur compounds that cause
halitosis (Liu et al. 2010 ).
Numerous studies have documented effective vaccination against oral patho-
gens. Most of these vaccines were developed based on the identification of viru-
lence factors that stimulate the induction of salivary immunoglobulin A antibody
responses. Primary targets have been cell-surface fibrillar proteins, which mediate
adherence to the salivary pellicle, and GFT enzymes, which synthesize adhesive
glucans and allow for microbial accumulation. Immunization when infants are
about 1 year old can establish effective immunity against ensuing colonization
attempts by mutans streptococci. Intranasal vaccines, targeting the flagellin of
S. mutans, have shown reduction of caries in animals (Shi et al. 2012 ; Sun
et al. 2012 ). Streptococcal GTF have also been demonstrated to be effective
components of dental caries vaccines, and different peptides from these proteins
have been used to design them (Culshaw et al. 2007 ; Russell et al. 2004 ).