[Study of bacterial flora in the oral cavity and stomach of elderly patients receiving nasogastric tube feeding]

To investigate the significance of oropharyngeal flora and gastric flora in elderly patients receiving nasogastric tube feeding, throat secretions and gastric aspirates were cultured and the pH of the latter was measured. Of 116 bacterial isolates from throat secretions of 27 elderly patients, 30 were beta-streptococci and 28 were Pseudomonas aeruginosa. Bacteria isolated from gastric aspirates numbered 86 and 24 (27.9%) of them were the same species as those found in the throat secretions. Patients with gastric pH were below 3.5 had significantly lower concentrations of gram-negative bacili in gastric aspirates. We also studied oropharyngeal flora in 33 elderly patients who were admitted to Nagoyashi Koseiin Geriatric Hospital. The major bacterial isolates from throat swabs of bedridden patients were gram-negative bacilli and beta-streptococci, especially group B streptococci (GBS). We measured the level of antibody to GBS in these patients. Those from whom GBS were isolated had high titers. These results suggest that in elderly patients receiving enteral nasogastric) tube feeding, large numbers of bacteria colonize the oral cavity and stomach. The measurement of type-specific antibody to GBS may be useful in managing such patients.