Postinflammatory cataracts in the mouse: induction by human mycoplasma-like organisms

Cataracts often occur in humans secondary to uveitis. Uveitis may be caused by various infectious agents, but rarely is the agent detected in the cataract. Mycoplasma-like organisms (MLO) were recently reported to cause human uveitis and retinitis. Cataracts were often present in those inflamed eyes. MLO are intracellular cell wall deficient pathogenic bacteria. They are pleomorphic tubulospherical and filamentous organisms with a characteristic ultrastructural appearance. No MLO culture system has been found despite 20 years of effort. The diagnosis of MLO disease rests on detection of the organisms in parasitised cells by a transmission electron microscope and response to antibiotics. In human intraocular inflammatory disease MLO are detectable in parasitised leucocytes and retinal pigment epithelial cells at the disease sites. Inoculation of MLO from a human source into mouse eyelids produced intraocular, chronic, progressive, inflammatory disease, with intraocular leucocytes parasitised by MLO in 15 of 100 mice versus 0 in 200 controls (p less than 0.05). This report describes the cataracts with MLO-parasitised intralenticular leucocytes in the inflamed eyes of 14 of those 15 mice versus 0 in 200 control mice (p less than 0.05). The results indicate that MLO penetrated the lens capsules to produce the cataracts, and they suggest that MLO could cause human cataracts. Alternative methods for detection of MLO and rifampin treatment of MLO intraocular disease are discussed.