In vitro biofilm model for studying tongue flora and malodour.
OBJECTIVE
To develop a perfusion biofilm system to model tongue biofilm microflora and their physiological response to sulfur-containing substrates (S-substrates) in terms of volatile sulfide compound (VSC) production.


RESULTS
Tongue-scrape inocula were used to establish in vitro perfusion biofilms which were examined in terms of ecological composition using culture-dependent and independent (PCR-DGGE) approaches. VSC-specific activity of cells was measured by a cell suspension assay, using a portable industrial sulfide monitor which was also used to monitor VSC production from biofilms in situ. Quasi steady states were achieved by 48 h and continued to 96 h. The mean (+/-SEM) growth rate for 72-h biofilms (n=4) was micro=0.014 h(-1) (+/-0.005 h(-1)). Comparison of biofilms, perfusate and original inoculum showed their ecological composition to be similar (Pearson coefficient>0.64). Perfusate and biofilm cells derived from the same condition (co-sampled) were equivalent with regard to VSC-specific activities which were up-regulated in the presence of S-substrates.


CONCLUSIONS
The model maintained a stable tongue microcosm suitable for studying VSC production; biofilm growth in the presence of S-substrates up-regulated VSC activity.


CONCLUSIONS
The method is apt for studying ecological and physiological aspects of oral biofilms and could be useful for screening inhibitory agents.
Spencer
P
P
Centre for Research in Biomedicine, Faculty of Applied Sciences, University of the West of England, Bristol, BS16 1QY, UK.
Greenman
J
J
McKenzie
C
C
Gafan
G
G
Spratt
D
D
Flanagan
A
A
D001421:Bacteria, Anaerobic / Q000235:genetics / Q000254:growth & development; D018441:Biofilms / Q000254:growth & development*; D015169:Colony Count, Microbial; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D006209:Halitosis / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D008954:Models, Biological; D016133:Polymerase Chain Reaction / Q000379:methods; D013440:Sulfides / Q000378:metabolism; D014059:Tongue / Q000382:microbiology*
D004269:DNA, Bacterial; D013440:Sulfides