Oxygen consumption by bacteria: a possible cause of negative middle ear pressure in ears with otitis media.
CONCLUSIONS
Oxygen consumption by bacteria could be a cause of the negative middle ear pressure in ears with otitis media (OM).


OBJECTIVE
To determine whether oxygen consumption by bacteria could be a cause for production of negative pressure in ears with OM.


METHODS
Hermetically sealed bottles containing high dose (group A) and low dose (group B) of Streptococcus pneumoniae with air space and maintained at 37 degrees C in a water bath were connected to a micropressure sensor. The chronological pressure changes were monitored in vitro for 3-13 h and were compared with those in the control bottles containing culture medium only.


RESULTS
The pressure of the group A samples showed significantly lower values than that of controls 3 h later (p<0.0001). In group B, the pressure was also significantly lower than that in the control group (p<0.0001). The partial pressures of oxygen measured at the beginning and end of the experiment in the six samples in group B showed significant decrease, while that in the control group showed only a slight decrease (p<0.0019).
Department of Otolaryngology-Head and Neck Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. kkyoko@nagasaki-u.ac.jp
Kyoko
K
Kitaoka
Satoru
S
Kaieda
Haruo
H
Takahashi
Haruo
H
Yoshida
Kenji
K
Takasaki
Hidetaka
H
Kumagami
D004432:Ear, Middle / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D010033:Otitis Media / Q000378:metabolism / Q000503:physiopathology*; D010100:Oxygen / Q000378:metabolism*; D011312:Pressure; D013296:Streptococcus pneumoniae / Q000378:metabolism*
D010100:Oxygen