Exogenously supplied
pyochelin influenced the virulence of Pseudomonas cepacia
pyochelin-negative strains in a chronic pulmonary
infection model in rats. Groups of rats were inoculated transtracheally with
agar beads containing P. cepacia or P. aeruginosa strains, saturated with either
pyochelin or PBS. Supplementation of the inocula with
pyochelin had no effect on the number of bacteria recovered from the lungs. The availability of
pyochelin, however, increased the degree of pathology observed in lungs infected with
pyochelin-negative strains of P. cepacia. The area of pathological involvement in the lung was about 2-fold larger, when
pyochelin was present. Inclusion of
pyochelin in the inoculum had no effect on the degree of pathology observed in lungs infected with a
pyochelin-positive P. aeruginosa strain.
Pyochelin was shown to stimulate in vitro growth of P. cepacia, but it had no effect on production of
lipase or
protease, factors which may be involved in P. cepacia virulence. These studies support our hypothesis that
pyochelin may be important for dissemination in P. cepacia
infections.