title: Detection and identification of oral anaerobes in intraoperative bronchial fluids of patients with pulmonary carcinoma.
abstract: Postoperative pneumonia may occur when upper respiratory tract protective reflexes such as cough and/or swallowing reflexes are impaired; thus, silent aspiration of oral bacteria may be a causative factor in postoperative pneumonia. This study aimed to quantify and identify bacteria in intraoperative bronchial fluids and to evaluate the relationship between impairment of cough/swallowing reflexes and silent aspiration of oral bacteria in elderly patients. After obtaining informed consent, cough and swallowing reflexes were assessed using an ultrasonic nebulizer and a nasal catheter, respectively. Using a micro-sampling probe, intraoperative bronchial fluids were collected from nine subjects with pulmonary carcinoma and cultured anaerobically on blood agar plates. After 7 days, CFUs were counted and isolated bacteria were identified by 16S rRNA gene sequencing. Four subjects (aged 71.0 ± 8.4 years) had impaired swallowing reflexes with normal cough reflexes, whereas five subjects (73.6 ± 6.5 years) had normal cough and swallowing reflexes. The bacterial counts (mean CFU ± SD) tended to be higher in intraoperative bronchial fluids of subjects with impaired swallowing reflexes ([5.1 ± 7.7] × 10(5)) than in those of subjects with normal reflexes ([1.2 ± 1.9] × 10(5)); however, this difference was not statistically significant. Predominant isolates from intraoperative bronchial fluids were Streptococcus (41.8%), Veillonella (11.4%), Gemella (8.9%), Porphyromonas (7.6%), Olsenella (6.3%) and Eikenella (6.3%). These findings indicate that intraoperative bronchial fluids contain bacteria, probably derived from the oral microbiota, and suggest that silent aspiration of oral bacteria occurs in elderly patients irrespective of impairment of swallowing reflex.
authors.affiliation: Division of Oral Ecology and Biochemistry, Tohoku University Graduate School of Dentistry.
authors.forename: Ayako
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Takuichi
authors.initials: T
authors.lastname: Sato
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hoshikawa
authors.forename: Naoko
authors.initials: N
authors.lastname: Ishida
authors.forename: Naoko
authors.initials: N
authors.lastname: Tanda
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Takahashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001421:Bacteria, Anaerobic / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D002277:Carcinoma / Q000382:microbiology* / Q000601:surgery; D003679:Deglutition; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008175:Lung Neoplasms / Q000382:microbiology* / Q000601:surgery; D008297:Male; D009055:Mouth / Q000382:microbiology*; D018410:Pneumonia, Bacterial; D011183:Postoperative Complications; D012021:Reflex, Abnormal
keywords: 16S ribosomal RNA; intraoperative bronchial fluids; oral bacteria; silent aspiration