Teitl: Denture acrylic biofilms: microbial composition, interactions and infection

Arianwyr
Engineering and Physical Sciences Research Council

Prif Ymchwiliwr

Morse, Daniel

Cyd-Ymchwilwyr
Williams, David
Wilson, Melanie
Wei, Xiao-Qing
Lewis, Michael

Manylion y Prosiect

Dyddiad dechrau: 01.10.2013

Dyddiad gorffen: 30.09.2017

Crynodeb

Denture-associated stomatitis (DS), a
frequent infection in denture-wearers (up to 60%), presents as areas of palatal
inflammation and is normally associated with denture biofilms containing Candida albicans. However, the
contribution of co-existing bacteria in these biofilms to the infection remains
unclear. As current DS management strategies are primarily directed towards Candida, research demonstrating the
impact of specific bacteria upon infection prognosis is important to improve
treatment regimes. This research evaluated the in vitro impact of bacteria on Candida
virulence, and compared bacterial microbiomes at specific oral sites in DS and
non-DS patients to determine associations with infection.


In vitro biofilm studies assessed expression of
C. albicans virulence factors
(morphological transformation, adhesins, hydrolytic enzymes) and their impact
on pathogenesis in an infection model. In clinical studies, microbiological
samples were obtained from the tongue, palate and denture-fitting surface of 19
denture-wearing patients (DS n=8, non-DS n=11). The presence of Candida was ascertained by PCR.
Bacterial DNA was extracted and subjected to next generation sequencing using
bacterial 16S rRNA gene targets, and differences in the bacterial microbiomes
determined.


Certain bacterial species in acrylic
biofilms significantly (P<0.05) increased the expression of C. albicans virulence factors, and
subsequently, enhanced tissue damage in model systems. Candida was detected in clinical samples of 14 patients (DS n=6,
non-DS n=8). Metataxonomic analyses revealed differences in relative abundance
of bacterial species, but no significant differences in the bacterial
microbiomes of the denture-fitting surface and palate between DS and non-DS
patients. Importantly, a significant (P=0.007) increase in the number of
bacterial species was evident for the tongue microbiome of non-DS patients.


The in vitro modulating capacity of bacteria toward Candida virulence, and the observed
species-level differences in bacteria between DS and non-DS patients highlight
the need for consideration of the bacterial composition of oral biofilms in the
pathogenesis of DS.