Experimental pneumonia produced by clinical isolates of Pseudomonas cepacia in mice.
An experimental Pseudomonas cepacia lung infection was induced in ddY mice pretreated with cyclophosphamide. A single dose of 250 mg of cyclophosphamide per kg resulted in leukopenia which lasted for four days. At the lowest PMN levels, the mice were exposed to various doses of bacteria by either intratracheal inoculation or aerosol inhalation. Experimental pneumonia was established by intratracheal inoculation of 1 x 10(7) - 2 x 10(8) colony-forming units of P. cepacia. The duration of survival time of the mice and the number of viable bacteria in their lungs were determined. A dramatic rise in the viable counts of P. cepacia was found within 24 hours after intratracheal inoculation of 1 x 10(8) colony-forming units of P. cepacia. It was impossible to establish P. cepacia pneumonia by aerosol inhalation, since the bacteria were immediately cleared from the lung. Mice which had not been treated with cyclophosphamide remained healthy and did not show any lung lesions. Thus, neutrophils appear to play an important role in the early defense mechanisms of the lung against P. cepacia. This animal model could be of use in evaluating additional therapies for the infection, and the pathologic determinants of infection caused by P. cepacia.
Yamagishi
Y
Y
First Department of Internal Medicine, Kagawa Medical School.
Fujita
J
J
Takigawa
K
K
Miyawaki
H
H
Takahara
J
J
Yamadori
I
I
Negayama
K
K
Fujimaki
K
K
Nakazawa
T
T
D000818:Animals; D016956:Burkholderia cepacia / Q000472:pathogenicity*; D003520:Cyclophosphamide / Q000494:pharmacology; D004195:Disease Models, Animal; D007165:Immunosuppression Therapy; D007970:Leukopenia / Q000209:etiology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011014:Pneumonia / Q000276:immunology*; D011552:Pseudomonas Infections / Q000276:immunology*
D003520:Cyclophosphamide