Colonisation on the tongue surface by respiratory pathogens in residents of a nursing home – a pilot study


Dr Y. Sumi, Director, Division of Oral and Dental Surgery, Department of Advanced Medicine, National Center for Geriatrics and Gerontology, 36-3, Gengo, Morioka, Obu-City 474-8511, Japan.
Tel.: 81-562-46-2311 ext. 7120
Fax: 81- 562-44-8518


Objective:  The morbidity and mortality of the dependent elderly that result from aspiration pneumonia have been recognised as a major geriatric health problem. The tongue has an extremely large surface area and due to its papillary structure can retain considerable quantities of food, and thus can support and harbour a large bacterial population. The purpose of this study was to gain more information on the microflora of the tongue surface and to assess the existence of oral infectious pathogens potentially causing respiratory disease in nursing home residents.

Subjects and methods:  The tongue bacterial flora of 69 nursing home residents were examined to identify microorganisms by the culture method.

Results:  Thirteen species of microorganisms were detected from the tongue in this study. In 41 of 69 subjects (59%), potential respiratory pathogens, had colonised the tongue surface.

Conclusion:  The results of the present study revealed that bacteria that commonly cause respiratory infection colonised the tongue of nursing home residents, suggesting that it may function as a reservoir of potential respiratory pathogens to facilitate colonisation on the oropharynx.