TY - JOUR
T1 - Contribution of toxin A and elastase to virulence of Pseudomonas aeruginosa in chronic lung infections of rats
AU - Woods, D. E.
AU - Cryz, S. J.
AU - Friedman, R. L.
AU - Iglewski, B. H.
PY - 1982
Y1 - 1982
N2 - A chronic pulmonary infection model in rats was employed to assess the role of individual Pseudomonas aeruginosa exoproducts in disease due to this organism. Groups of rats were inoculated transtracheally with agar beads in which were embedded approximately 104 colony-forming units of P. aeruginosa PAO and the PAO derivatives PR1, T1, E64, and a mixture of T1 and E64 in equal numbers (104). Eight animals from each group were sacrificed at 3, 9, and 30 days after challenge, and their lungs were examined for histopathological changes, bacterial numbers, and the presence of P. aeruginosa exoproducts. The Tox- mutant T1 and the PR1 mutant, which produces enzymatically inactive toxin A, were both found to be less virulent in the rat lung model than was the toxigenic parental strain PAO. Pathological changes seen in animals infected with these mutants were restricted to intra- and peribronchial inflammation, whereas the toxigenic parental strain caused parenchymal changes, including a dense mononuclear-cell infiltration in the laveolar spaces in addition to intra- and peribronchial inflammation. Additionally, mutant E64, which produces a temperature-sensitive elastase, was also found to be less virulent in the rat lung model than was the parental strain. These data demonstrate that both active toxin A and elastase are required for maximum virulence of P. aeruginosa in this model.
AB - A chronic pulmonary infection model in rats was employed to assess the role of individual Pseudomonas aeruginosa exoproducts in disease due to this organism. Groups of rats were inoculated transtracheally with agar beads in which were embedded approximately 104 colony-forming units of P. aeruginosa PAO and the PAO derivatives PR1, T1, E64, and a mixture of T1 and E64 in equal numbers (104). Eight animals from each group were sacrificed at 3, 9, and 30 days after challenge, and their lungs were examined for histopathological changes, bacterial numbers, and the presence of P. aeruginosa exoproducts. The Tox- mutant T1 and the PR1 mutant, which produces enzymatically inactive toxin A, were both found to be less virulent in the rat lung model than was the toxigenic parental strain PAO. Pathological changes seen in animals infected with these mutants were restricted to intra- and peribronchial inflammation, whereas the toxigenic parental strain caused parenchymal changes, including a dense mononuclear-cell infiltration in the laveolar spaces in addition to intra- and peribronchial inflammation. Additionally, mutant E64, which produces a temperature-sensitive elastase, was also found to be less virulent in the rat lung model than was the parental strain. These data demonstrate that both active toxin A and elastase are required for maximum virulence of P. aeruginosa in this model.
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U2 - 10.1128/iai.36.3.1223-1228.1982
DO - 10.1128/iai.36.3.1223-1228.1982
M3 - Article
C2 - 6807846
AN - SCOPUS:0020051553
SN - 0019-9567
VL - 36
SP - 1223
EP - 1228
JO - Infection and Immunity
JF - Infection and Immunity
IS - 3
ER -