Tano Y, Nakamura J, Matsushima T, Tanabe J, Kimura M
Second Department of Internal Medicine, Kawasaki Medical School, Kawasaki Hospital.
Kansenshogaku Zasshi. 1993 Jul;67(7):665-72. doi: 10.11150/kansenshogakuzasshi1970.67.665.
To evaluate the mechanism of lower respiratory tract infection in the hospital, gastric juice, throat secretions, secretions in tracheal cannulae or tubes and aspirated sputum were cultured simultaneously in seven patients with tracheostomy and seven patients with tracheal intubation. Thirty-six strains of bacteria were isolated from gastric juice and only 22.2% of them were the same bacteria as those in the throat secretions. This suggested that there was little correlation between gastric and oropharyngeal flora. The bacteria isolated from throat secretions and aspirated sputum showed 38.5% coincidence in tracheostomized patients and 80% coincidence in intubated patients. In addition, the rate of agreement was 33.3% in tracheostomized patients and 88.9% in intubated patients between throat secretions and tracheal cannulae or tubes. These findings suggested that the correlation of bacterial flora between the upper and lower respiratory tracts was high in intubated patients and low in tracheostomized patients. Identical bacteria in the stomach and the upper and lower respiratory tracts (which may cause nosocomial infection) were isolated in only four of the 14 patients. It has been suggested that bacterial flora in the lower respiratory tract are transmitted from the stomach to the oropharynx and then cause lower respiratory tract infection in hospital. However, our study suggested that this was not a common pathogenic mechanism.
为评估医院下呼吸道感染的机制，对7例气管切开患者和7例气管插管患者同时进行胃液、咽喉分泌物、气管套管或导管内的分泌物以及吸出痰液的培养。从胃液中分离出36株细菌，其中只有22.2%与咽喉分泌物中的细菌相同。这表明胃和口咽菌群之间几乎没有相关性。在气管切开患者中，从咽喉分泌物和吸出痰液中分离出的细菌有38.5%一致，在插管患者中这一比例为80%。此外，气管切开患者咽喉分泌物与气管套管或导管内细菌的一致率为33.3%，插管患者为88.9%。这些发现表明，插管患者上、下呼吸道细菌菌群的相关性较高，气管切开患者则较低。在14例患者中，只有4例在胃以及上、下呼吸道中分离出相同细菌（可能导致医院感染）。曾有观点认为，下呼吸道细菌菌群是从胃传播至口咽，进而导致医院内下呼吸道感染。然而，我们的研究表明这并非常见的致病机制。
