The prognosis of chronic
respiratory tract infection with Pseudomonas aeruginosad considered to be poor. However, low-dose and long-term 14 membered
macrolide, such as
erythromycin or
clarithromycin, treatment has been reported as effective clinically in chronic lower
respiratory tract disease. There was no report to investigate the effect of
macrolide on chronic biofilm related Pseudomonas aeruginosa
respiratory tract infection in vivo. In a newly established murine model of chronic Pseudomonas aeruginosa respiratory
infection mimicking
diffuse panbronchiolitis (DPB), we investigated the effect of erythromcin inhalation on viable bacteria in the lungs.
Infection was produced by placement of a
plastic tube in the bronchus with inoculating. Pseudomonas aeruginosa suspended in saline was also inoculated in bronchus after intubation of the tube. Viable bacteria were constantly isolated
at 10(4) 10(6) cfu-specimen from the lungs for more than 30 days. Treatment with
erythromycin inhalation for four days reduced the number of viable bacteria in the lungs with statistically significant. Our result indicated that our new model of chronic
respiratory tract infection is simple and provides a useful tool to study the pathogenic process and treatment of such
infection. Our results also suggest that the
erythromycin inhalation is effective on chronic Pseudomons aeruginosa respiratory
infection.