Studies on the quantitation of intraocular Treponema pallidum. An in vitro model.

Smith and Israel (1967a, 1967b, 1968) and Goldman and associates (Goldman and Girard, 1968; Girard, Goldman, Baumstark, and Stickle, 1967) have recently reported that spiral organisms, some of which are motile, can be demonstrated in the aqueous humour (AH), cerebrospinal fluid (CSF), and tissues of adequately treated syphilitic patients. Most of these organisms are morphologically indistinguishable from Treponema pallidum and can be demonstrated by direct immunofluorescent techniques. These investigators strongly suggest that these spiral organisms, some of which have been transferable to animals (Smith and Israel, 1968), are T. pallida. Recently, Chandler and Cannefax (1969) have established that immunofluorescent techniques can be more efficient than darkfield microscopy for the demonstration of T. pallidum in body fluids. T. pallidum-like organisms thus far reported in ocular fluids have been very few in number when detected by either darkfield microscopy or direct immunofluorescent staining. Clinical studies to date have been qualitative in nature, and a method to relate the number of treponemes observed on the final direct fluorescent antibody (FA) slide to the approximate number of organisms per unit volume of AH would be highly desirable in order to establish an initial base line. Against this base line the evolution of infection may be measured and the response to therapy assessed. Itwould further benefit the investigator to have data indicating the smallest number of treponemes that could reasonably be detected per unit volume of fluid when direct immunofluorescent techniques are used. This paper