Reducing the variability between constant-depth film fermenter experiments when modelling oral biofilm
Article first published online: 13 JUL 2012
© 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 113, Issue 3, pages 601–608, September 2012
How to Cite
Hope, C.K., Bakht, K., Burnside, G., Martin, G.C., Burnett, G., de Josselin de Jong, E. and Higham, S.M. (2012), Reducing the variability between constant-depth film fermenter experiments when modelling oral biofilm. Journal of Applied Microbiology, 113: 601–608. doi: 10.1111/j.1365-2672.2012.05368.x
- Issue published online: 14 AUG 2012
- Article first published online: 13 JUL 2012
- Accepted manuscript online: 20 JUN 2012 09:18AM EST
- Manuscript Accepted: 2 JUN 2012
- Manuscript Revised: 25 MAY 2012
- Manuscript Received: 2 MAY 2012
- Biotechnology and Biological Sciences Research Council. Grant Numbers: BBSRC/CASE, BB/G529659/1
- constant-depth film fermenter;
- dental plaque;
- in vitro modelling
The inherent instabilities associated with the development of multispecies biofilm communities within the constant-depth film fermenter (CDFF) and other microcosm systems can yield unacceptable variability between experiments, which could limit their potential applications in oral microbiology. The extent of this variability needs to be determined and a protocol developed which minimizes it.
Methods and Results
Two custom-made CDFFs were supplied concurrently with the same inoculation culture, begat from an aliquot of a saliva pool and artificial saliva growth medium via a dual-channel pump. Transformed log10 data of the viable counts at fixed time points were analysed using the Bland–Altman approach to test for the levels of agreement between two CDFFs running concurrently and those CDFFs run in series. The coefficients95% of agreement were lower (i.e. less variable) in the concurrent model than when run in series for total counts of bacteria (1·238 vs 2·124), Lactobacillus spp. (0·517 vs 1·431) and Mutans streptococci (2·817 vs 3·864). Other measures of variability showed a similar trend.
Operating CDFFs concurrently minimizes the degree of difference and variability between them.
Significance and Impact of the Study
Operating CDFFs concurrently will improve the sensitivity for experiments that seek to determine the effects of a variable, such as a nutritional supplement or antimicrobial agent, and a control.