Bacterial proteases and adherence of Pseudomonas aeruginosa to mouse cornea.

The goal of this study was to test whether bacterial exoproducts, such as elastase or alkaline protease contribute to the initial binding of Pseudomonas aeruginosa to mouse corneal epithelium. Each protease, purified from P. aeruginosa, when applied exogenously at concentrations of either 25 or 50 ng ml-1, elevated binding of Pseudomonas to mouse cornea in organ culture. Polyclonal antibodies against bacterial alkaline protease, but not elastase, interfered with bacterial binding and reduced significantly the number of organisms bound to cornea in an organ culture binding inhibition assay. Zymographic analysis of conditioned media from additional organ culture experiments showed that the P. aeruginosa strain used, which is highly virulent in cornea in vivo, secretes detectable levels of alkaline protease, but not elastase in vitro and that secretion was enhanced if the corneal epithelium was wounded. Lastly, how alkaline protease enhanced bacterial binding to the corneal epithelium of the organ cultured eye was examined. Data from this study suggest that exposure of lipase-sensitivity epithelial receptors represents at least one mechanism.