Prevalence of potential respiratory pathogens in the mouths of elderly patients and effects of professional oral care.

To evaluate the effectiveness of professional oral health care in reducing the risk of aspiration pneumonia, we examined the prevalence of potential respiratory pathogens in gargled samples from elderly persons. Samples were obtained from 54 elderly subjects over 65 years of age who required daily nursing care, from 21 healthy elderly subjects over 65 years old, and from 22 healthy young subjects under 30 as controls. The prevalence of possible pathogens was determined by culture and the polymerase chain reaction. The percentages detected in samples of Streptococcus pneumoniae, Staphylococcus species, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans from elderly patients requiring daily nursing care were 63.0, 37.0, 14.8, 5.6 and 66.7, respectively. The numbers of C. albicans cells recovered in samples from elderly subjects were significantly higher than those recovered from the healthy young group (P<0.001). Elderly patients needing daily care and receiving professional oral health care had lower prevalences and cell numbers of C. albicans than did the elderly patients without such oral care. This study showed that professional oral health care in elderly requiring daily nursing care reduced the cell numbers of potential respiratory pathogens.