• 11/25/2007
  • web-based article
  • Samuel J. Hooper et al.
  • J Med Microbiol 56 (2007), 1651-1659

In order to characterize the bacterial microbiota present within oral cancerous lesions, tumorous and non-tumorous mucosal tissue specimens (approx. 1 cm3) were harvested from ten oral squamous cell carcinoma (OSCC) patients at the time of surgery.

Any microbial contamination on the surface of the specimens was eliminated by immersion in Betadine and washing with PBS. Bacteria were visualized within sections of the OSCC by performing fluorescent in situ hybridization with the universal oligonucleotide probe, EUB338. DNA was extracted from each aseptically macerated tissue specimen using a commercial kit. This was then used as template for PCR with three sets of primers, targeting the 16S rRNA genes of Spirochaetes, Bacteroidetes and the domain Bacteria. PCR products were differentiated by TA cloning and bacterial species were identified by partial sequencing of the 16S rRNA gene fragments.

A total of 70 distinct taxa was detected: 52 different phylotypes isolated from the tumorous tissues, and 37 taxa from within the non-tumorous specimens. Differences between the composition of the microbiotas within the tumorous and non-tumorous mucosae were apparent, possibly indicating selective growth of bacteria within carcinoma tissue. Most taxa isolated from within the tumour tissue represented saccharolytic and aciduric species. Whether the presence of these bacteria within the mucosa has any bearing on the carcinogenic process is a concept worthy of further investigation.

Authors:
Samuel J. Hooper1, St-John Crean1, Michael J. Fardy1, Michael A. O. Lewis1, David A. Spratt2, William G. Wade3 and Melanie J. Wilson1

Authors’ affiliations:
1 Department of Oral Surgery, Medicine and Pathology, Cardiff University, Cardiff CF14 4XY, UK

2 Division of Microbial Diseases, Eastman Dental Institute, University College London, 256 Gray’s Inn Rd, London WC1X 8LD, UK

3 King’s College London Dental Institute at Guy’s, King’s College and St Thomas’ Hospitals, Infection Research Group, London SE1 9RT, UK