UCL Eastman Dental Institute

Biofilms and ecology

Research Focus

This group is investigating biofilms for shifts in the microbial populations, and the ecology of micro-organisms infecting the mouth.

The group were the first to model the microbial population shifts associated with the development and regression of gingivitis. When disease results from changes in the resident microbiota, the use of such models permits the influence of individual environmental factors to be assessed and also allows the effects of potential treatments to be examined (EPSRC). Molecular biology and community analysis approaches have been developed and used to understand the microbial structure of oral biofilm communities in health and disease. These techniques, coupled with powerful statistical analysis, have revealed specific community profiles associated with various disease states e.g. health and periodontal disease (BBSRC, GlaxoSmithKline). The importance of biofilms in the clinical setting is evident and the sustainability of research in this area is evidenced by recent grant awards from the BBSRC and EPSRC to develop novel methods for disrupting oral biofilms and biofilms of Stapylococcus epidermidis on catheters. These novel approaches involve the molecular breeding of enzymes able to disrupt the biofilm matrix and, as well as being of great clinical importance, will also lead to a greater understanding of the function and manipulation of bacterial enzyme-encoding genes.

Ecological studies on viral disease relevant to the mouth and systemic disease, funded by NIH, have established the mouth as a common site of residence of Human Herpes Virus 8 (HHV-8 - the cause of Kaposi's sarcoma), demonstrated that non-sexual transmission from the mouth is common and, of relevance to potential therapy, were the first to describe multiple infections by different HHV-8 isolates in the mouth, these being different to those infecting other body compartments. Research on oral fungal ecology has clearly established, through the group's large scale studies, the influence of diabetes mellitus upon the frequency of Candida albicans oral carriage, character (including strain relatedness) and antimicrobial resistance. To develop methods of circumventing such resistance, the group has defined the in-vitro sensitivities of oral candidal isolates to novel agents (i.e. synthetic killer peptides). 

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Research Outcomes

• Dalwai F, Spratt DA and Pratten J. 2007
  The use of quantitative PCR and culture methods to characterise ecological flux's in bacterial biofilms.
  Journal of Clinical Microbiology 45(9): 3072-3076

• Manfredi M, McCullough MJ, Al-Karaawi ZM, Vescovi P and Porter SR. 2006
  Analysis of the strain relatedness of oral Candida albicans in patients with diabetes mellitus using polymerase chain reaction-fingerprinting.
  Oral Microbiology Immunology 21(6): 353-359

• Ciantar M, Gilthorpe MS, Hurel SJ, Newman HN, Wilson M and Spratt DA. 2005.
  Capnocytophaga spp. in periodontitis patients manifesting diabetes mellitus.
  Journal of Periodontology 76(2): 194-203

• Lamfon H, Porter SR, McCullough M and Pratten J. 2004
  The susceptibility of Candida albicans biofilms grown in a constant depth film fermentor to chlorhexidine, fluconazole and miconazole: a longitudinal study.
  Journal of Antimicrobial Chemotherapy 53: 383-385