Control of Polymicrobial Biofilms: Recent Trends - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 329

peptide [CSP] molecules produced by S. mutans ) with an antimicrobial peptide.
CSP-based STAMPs were internalized by S. mutans and this resulted in their death.
Because CSPs are strain/species specific (Suntharalingam and Cvitkovitch 2005 ),
S. mutans was shown to be specifically targeted while other oral streptococci were
unaffected. The team (Eckert et al. 2006 ) also suggested that, in the future,
STAMPs could be produced by certain nonpathogenic resident oral species to act
as artificially created probiotic organisms.
While not addressed in this section, it should be noted that the understanding of
novel approaches to inhibit the complex autoinducer peptide cell-cell signaling
system of the staphylococci are coming to fruition. Because of the strain/species
specificity of this type of cell-cell signaling system, interesting targeted approaches
have the potential to be developed (the reader is directed to the section on Staph-
ylococcus aureus biofilm inhibitors in Chap. 11, by Alex Horswill).

3.3 Manipulation of Coaggregation

Coaggregation is the specific recognition and adhesion of different species of
bacteria to one another (Kolenbrander 1988 ). Originally discovered in the early
1970s (Gibbons and Nygaard 1970 ; Cisar et al. 1979 ) and considered to be a simple
mechanism by which bacteria can integrate into dental plaque (Kolenbrander and
London 1993 ), it has become clear that coaggregation is likely essential for
numerous roles in maintaining homeostasis in multispecies biofilms in a variety
of environments and between taxonomically disparate species (Bos et al. 1999 ;
Rickard et al. 2003 ; Kolenbrander et al. 2006 ; Hojo et al. 2009 ; Shirtliff et al. 2009 ).
Thus, if coaggregation is integral to polymicrobial biofilm development and the
interaction of different species in a biofilm, approaches to prevent, restructure, or
destabilize polymicrobial biofilms through manipulating coaggregation interactions
would offer attractive alternatives to traditional anti-biofilm/antimicrobial

strategies.
A key role for coaggregation is to facilitate cellular juxtaposition. Work by oral
microbiologists has shown that coaggregation has roles in bringing species in close
proximity to facilitate cell-cell signaling (Fig. 1 ) and also for the exchange of
metabolites (Kolenbrander et al. 2010 ). Indeed, work by Egland et al. ( 2004 ) has
shown that in order for biofilm populations of the oral bacterium Veillonella atypica
PK1910 to grow in biofilms, the species need to be juxtaposed to S. gordonii V288.
This pair, coincidently, coaggregates strongly, and the authors speculated that
coaggregation is required to enhance the growth of V. atypica (Egland
et al. 2004 ; Kolenbrander et al. 2010 ).
The importance of coaggregation in supporting the retention of species is not
limited to dental plaque biofilms (Rickard et al. 2003 ). Recent work by Min and
Rickard ( 2009 ) demonstrated that coaggregation was also required by the fresh-
water bacterium Sphingomonas natatoria 2.1 in order to compete with Micrococcus
luteus 2.13. A spontaneous coaggregation-deficient mutant of S. natatoria 2.1 was