Transmission electron microscope study of bacterial morphotypes on the anterior dorsal surface of human tongues

The human tongue has been the subject of many cytological and histological studies. When a literature search disclosed no reports of the ultrastructur e of the morphotypes of bacteria residing on the tongue's surface, a transm ission electron microscope study of ultrathin sections of bacteria obtained by scraping eight human tongues was undertaken. The scrapings from the ant erior dorsal tongue surfaces, processed conventionally for electron microsc ope study, revealed 33-35 different bacterial morphotypes. Several of the m orphotypes were unique to a tongue. Morphotype differences were also relate d to donor characteristics such as smoking, tongue site, location in centri fuge pellet, diet, and medications. The predominant morphotypes were Gram-p ositive cocci. These preliminary findings suggest that the microbiota of th e human tongue and variations in that microbiota, related to physical condi tion, Lifestyle, medications, and dietary preferences, merit more attention from anatomists. Anat Rec 259:276-287, 2000. (C) 2000 Wiley-Liss, Inc.