Pathogenesis of the mouse keratitis produced with Pseudomonas aeruginosa.

For the purpose of studying the pathogenesis of corneal infection of Pseudomonas aeruginosa, was examined virulence of elastase and protease producing strains or non-producing strains of the bacteria by using the cornea of mouse. The cornea of mouse was experimentally incised, and then P. aeruginosa cultures were dropped once onto it. As a result serious ulcers were caused over the entire cornea, and abscesses in its central area, by 10(5) and 10(7) viable cells of the enzymes producing strains IID 1210 and NO-5 of P. aeruginosa, respectively. Histological destruction, enlargement and cellular infiltration were observed in the corneal epithelium and stroma. On the other hand, P. aeruginosa strains NC-5 and N-10, enzymes non-producing ones, could not cause corneal lesions such as ulcers or abscesses. However, strain PA-103, which is considered to produce neither of the enzymes, could not cause corneal ulcers but cause uveitis even with 10(5) viable cells per mouse. Histologically, concentrated serous exudatation and severe cellular infiltration were noted in the anterior chamber. Necrosis was observed in the entire layer of the cornea. However, the corneal damage caused by strain PA-103 was clearly different from one due to the enzymes producing strains. Additive synergistic effect of protease on the virulent degree of strain NC-5 against the cornea was detected.