Accurate microbiological diagnostics are necessary for both clinical medicine and research. Sampling is the first and very crucial step in the process. Literature review reveals that none of the previously used methods are simultaneously both quantitative and representative for site-specific oral mucosal samples. In the present study the aim was to find a method that could give representative and quantitative results for samples from oral mucosa.
Methods:
Six different types of samples were collected from 14 volunteers in the study. Two saliva samples (unstimulated and stimulated), saline mouth rinse, swab sample, sponge imprint sample and filter paper imprint sample. The first five are those used in many previous studies and in routine practice. The filter paper sampling technique was developed for this study. The filter paper (Millipore Membrane filter GSWP02500, pore size 0.2µm) was placed on the mucosa for 30 seconds and thereafter agitated with glass beads in 5ml of physiological saline. All samples were cultured on a range of culture media under aerobic and anaerobic conditions. The number of viable bacteria and yeasts was determined and expressed as colony-forming units per milliliter.
Results: and conclusions:
The optimal site-specific sampling techniques were shown to be the swab and the filter paper sample. Both managed to collect a large number and variety of different oral microbes. The saliva and the mouth rinse samples were also sensitive but not site specific since saliva includes many microbes originated from teeth and other oral surfaces. The sponge sampling method was not reproducible. The filter paper sampling technique was easy to use and the results were representative of the oral flora and reproducible. It also gave quantitative data of microbes per unit area of oral mucosa necessary for sampling of oral lesions.