Treponema carateum

Abstract: An enzyme-linked immunosorbent assay (ELISA) for syphilis has been developed that detects IgG antibody to purified recombinant Treponema pallidum surface antigen 4D. The 4D ELISA was capable of detecting 25 ng of 4D antigen-specific antibody. Neither 172 nonsyphilitic sera nor 20 false-positive sera in the Venereal Disease Research Laboratory test reacted in the 4D ELISA. The sensitivity of the 4D ELISA was comparable to that of the adsorbed fluorescent treponemal antibody test in primary, secondary, and latent disease. Most sera from patients with yaws or pinta were also reactive, a result indicating that a 4D antigen-like molecule also exists in the closely related pathogenic treponemes Treponema pertenue and Treponema carateum.

Abstract: Inhabitants of a remote Panamanian village were examined for clinical and serological evidence of pinta infection. Of 104 persons examined, 21 (20^o) had clinical evidence of active or inactive pinta, and 54 (52^0) were seropositive. Sera were evaluated for antibody to individual Treponema pallidum antigens. Sera from all four patients with active pinta contained antibody to the 47-48-kilodalton major antigen; the intensity of reactivity and the number of antigens recognized increased with age and, presumably, duration of infection. Sera from six children with inactive pinta reacted strongly with multiple T. pallidum antigens, whereas adults with inactive pinta had less intense reactivity against fewer molecules. Seronegative controls demonstrated only weak reactivity to fewer than five molecules. The development of antibody reactivity to the full spectrum of T. pallidum antigens during the course of infection demonstrates the high degree of antigenic relatedness of T. pallidum and Treponema carateum and is similar to the development of humoral responsiveness during syphilis infection.

Abstract: Treponema and Brachyspira represent two clusters of the phylum Spirochetes that are either pathogenic or human host associated. Treponema pallidum subsp. pallidum, endemicum, and pertenue are the agents of venereal syphilis, endemic syphilis, and yaws, respectively, while Treponema carateum causes pinta. Numerous treponemal phylotypes in the oral cavity cause gingivitis or periodontitis. Brachyspira aalborgi, Brachyspira pilosicoli, and Brachyspira hominis cause human intestinal spirochetosis. T. pallidum subsp. pallidum is the only treponeme transmitted by sexual contact and vertically from a pregnant woman to her fetus; it is alsoe only pathogenic treponeme that regularly breaches the blood-brain barrier. Venereal syphilis remains a significant public health problem worldwide. Methods of laboratory identification of both Treponema and Brachyspira include direct detection methods such as dark-field microscopy, immunohistochemistry, and PCR. However, while Brachyspira can be cultured, syphilis diagnosis is highly dependent on serologic testing since T. pallidum can only be isolated by inoculation of rabbits (rabbit infectivity testing). Serologic testing for syphilis involves nontreponemal tests that detect antibodies directed against lipoidal antigens and treponemal tests that detect IgM and IgG antibodies directed against T. pallidum protein antigens. Newer treponemal assays now include enzyme immunoassays, point-of-care tests, chemiluminescence assays, immunoblots, and multiplex flow immunoassays, the majority of which use recombinant T. pallidum antigens. In-depth knowledge of these assays and their performance, as well as the application of the reverse syphilis screening algorithm, is critical for both laboratory and clinical practice.