Immunofluorescent Detection of Treponema pallidum: A Review

The status of immunofluorescent methods for the detection of Treponema pallidum is reviewed because of increasingly wide interest in these procedures. Since conventional staining procedures (fuchsin, acridine dyes, silver stains, etc) for demonstrating T pallidum are not specific for T pallidum , the detection of treponemes in primary and secondary syphilis has been based largely on dark-field microscopy of unstained wet preparations from fresh lesions. Such dark-field identifications of treponemes necessarily rely upon refractive characteristics, motility, and morphology. Results of examinations of material from oral lesions are not reliable because of the presence of treponemal flora that are indistinguishable from T pallidum by dark-field examination.