Chelation in experimental Pseudomonas keratitis

Abstract

Clinical isolates from pseudomonal infections of the human cornea were evaluated for their ability to produce proteolysis, both in vitro and in vivo. A crude enzyme preparation was obtained from cell-free filtrates of Pseudomonas aeruginosa grown for 36 hrs in a 5 per cent. peptone broth. When a minute amount of this enzyme was injected into the corneal stroma of the experimental animal, a necrosis mimicking a clinical infection was noted to occur within 12 hrs. This necrosis was inhibited to a considerable degree by the addition of 1o -2M disodium EDTA. Similarly experimental infections in the rabbit cornea, when treated with appropriate antibiotics and a topical application of disodium EDTA, were noted to resist the extensive colliquative necrosis seen in similar corneae treated with antibiotics only.