Effect of urokinase on the extracellular virulence properties of Pseudomonas aeruginosa and Burkholderia cepacia

The influence of urokinase and oxygen availability on growth, siderophore, protease and lipase production in Burkholderia cepacia and non-mucoid (PAO1 ) and mucoid (PaWH) strains of Pseudomonas aeruginosa was assessed for cell s grown in batch culture under iron-restriction. Siderophore production dec reased with increasing concentration of urokinase in B. cepacia independent of oxygen availability but decreased in both strains of P. aeruginosa only under oxygen-depleted conditions. Protease activity was enhanced for all t hree strains irrespective of oxygen content whereas lipase production incre ased in B. cepacia and decreased in PAO1 under both sets of growth conditio ns and varied with oxygen availability in PaWH. The evidence presented sugg ests that urokinase could contribute to the pathophysiology of pulmonary in fections.