Secondary Syphilis Patients Research Articles

TprC/D (Tp0117/131), a Trimeric, Pore-Forming Rare Outer Membrane Protein of Treponema pallidum, Has a Bipartite Domain Structure

Identification of Treponema pallidum rare outer membrane proteins (OMPs) has been a longstanding objective of syphilis researchers. We recently developed a consensus computational framework that employs a battery of cellular localization and topological prediction tools to generate ranked clusters of candidate rare OMPs (D. L. Cox et al., Infect. Immun. 78:5178-5194, 2010). TP0117/TP0131 (TprC/D), a member of the T. pallidum repeat (Tpr) family, was a highly ranked candidate. Circular dichroism, heat modifiability by SDS-PAGE, Triton X-114 phase partitioning, and liposome incorporation confirmed that full-length, recombinant TprC (TprC(Fl)) forms a β-barrel capable of integrating into lipid bilayers. Moreover, TprC(Fl) increased efflux of terbium-dipicolinic acid complex from large unilamellar vesicles and migrated as a trimer by blue-native PAGE. We found that in T. pallidum, TprC is heat modifiable, trimeric, expressed in low abundance, and, based on proteinase K accessibility and opsonophagocytosis assays, surface exposed. From these collective data, we conclude that TprC is a bona fide rare OMP as well as a functional ortholog of Escherichia coli OmpF. We also discovered that TprC has a bipartite architecture consisting of a soluble N-terminal portion (TprC(N)), presumably periplasmic and bound directly or indirectly to peptidoglycan, and a C-terminal β-barrel (TprC(C)). Syphilitic rabbits generate antibodies exclusively against TprC(C), while secondary syphilis patients fail to mount a detectable antibody response against either domain. The syphilis spirochete appears to have resolved a fundamental dilemma arising from its extracellular lifestyle, namely, how to enhance OM permeability without increasing its vulnerability to the antibody-mediated defenses of its natural human host.

P3-S6.10 Analysis of systemic and cutaneous immune responses helps explain the duality of immune evasion and recognition in secondary syphilis

BackgroundDespite the robust adaptive immune responses associated with secondary syphilis (SS), which include the presence of high titres of anti-T pallidum (Tp) antibodies with opsonizing activity, it may take months...

Azithromycin Treatment Failure Among Primary and Secondary Syphilis Patients in Shanghai

Azithromycin has been used to treat primary and secondary syphilis and as prophylaxis for sexual partners. We evaluated syphilis treatment failure in patients who received azithromycin therapy. Patients who did not respond to azithromycin therapy were referred to Shanghai Skin Disease and sexually transmitted disease hospital. Treatment failure was defined as follows: (1) persistent ulcers or cutaneous or mucosal lesions 1 month after therapy; or (2) detection of spirochetes in dark-field microscopy examination of a lesion at least 1 week after treatment; or (3) failure of rapid plasma reagin titers to decrease 4-fold at 3 months after treatment. A total of 132 patients with primary and secondary syphilis who failed azithromycin therapy were referred to our hospital between January 2001 and October 2008. Of 132 patients, 42 (31.8%) had primary syphilis and 90 (68.2%) had secondary syphilis. Twenty-six patients with primary syphilis developed multiple lesions or secondary syphilis, or persistent ulcers despite using azithromycin. The skin or mucosal lesions did not resolve in 37 patients with secondary syphilis after azithromycin treatment. Ten patients had a positive dark-field examination for Treponema pallidum (T. pallidum) after treatment. The serum rapid plasma reagin titers studied in all cases had failed to decrease 4-fold at 3 months after therapy. The doses of azithromycin used for treatment ranged from 4 to 30 g. The failure of azithromycin to cure a substantial number of patients with primary and secondary syphilis in Shanghai suggests that azithromycin has limited therapeutic value in this setting.

Secondary syphilis in cali, Colombia: new concepts in disease pathogenesis.

Venereal syphilis is a multi-stage, sexually transmitted disease caused by the spirochetal bacterium Treponema pallidum (Tp). Herein we describe a cohort of 57 patients (age 18–68 years) with secondary syphilis (SS) identified through a network of public sector primary health care providers in Cali, Colombia. To be eligible for participation, study subjects were required to have cutaneous lesions consistent with SS, a reactive Rapid Plasma Reagin test (RPR-titer ≥1∶4), and a confirmatory treponemal test (Fluorescent Treponemal Antibody Absorption test- FTA-ABS). Most subjects enrolled were women (64.9%), predominantly Afro-Colombian (38.6%) or mestizo (56.1%), and all were of low socio-economic status. Three (5.3%) subjects were newly diagnosed with HIV infection at study entry. The duration of signs and symptoms in most patients (53.6%) was less than 30 days; however, some patients reported being symptomatic for several months (range 5–240 days). The typical palmar and plantar exanthem of SS was the most common dermal manifestation (63%), followed by diffuse hypo- or hyperpigmented macules and papules on the trunk, abdomen and extremities. Three patients had patchy alopecia. Whole blood (WB) samples and punch biopsy material from a subset of SS patients were assayed for the presence of Tp DNA polymerase I gene (polA) target by real-time qualitative and quantitative PCR methods. Twelve (46%) of the 26 WB samples studied had quantifiable Tp DNA (ranging between 194.9 and 1954.2 Tp polA copies/ml blood) and seven (64%) were positive when WB DNA was extracted within 24 hours of collection. Tp DNA was also present in 8/12 (66%) skin biopsies available for testing. Strain typing analysis was attempted in all skin and WB samples with detectable Tp DNA. Using arp repeat size analysis and tpr RFLP patterns four different strain types were identified (14d, 16d, 13d and 22a). None of the WB samples had sufficient DNA for typing. The clinical and microbiologic observations presented herein, together with recent Cali syphilis seroprevalence data, provide additional evidence that venereal syphilis is highly endemic in this region of Colombia, thus underscoring the need for health care providers in the region to be acutely aware of the clinical manifestations of SS. This study also provides, for the first time, quantitative evidence that a significant proportion of untreated SS patients have substantial numbers of circulating spirochetes. How Tp is able to persist in the blood and skin of SS patients, despite the known presence of circulating treponemal opsonizing antibodies and the robust pro-inflammatory cellular immune responses characteristic of this stage of the disease, is not fully understood and requires further study.

Azithromycin Treatment Failure Among Primary and Secondary Syphilis Patients in Shanghai

Azithromycin Treatment Failure Among Primary and Secondary Syphilis Patients in Shanghai

Characterization of the 35-kilodalton Treponema pallidum subsp. pallidum recombinant lipoprotein TmpC and antibody response to lipidated and nonlipidated T. pallidum antigens

The gene encoding the 35-kDa immunogenic Treponema pallidium subsp. pallidum (T. pallidum) membrane protein C, TmpC, was cloned, sequenced, and expressed in Escherichia coli. The deduced amino acid sequence carries on N-terminal signal sequence with a four-amino-acid motif, which is characteristic for bacterial lipoproteins. Metabolic labeling with radioactive palmitic acid of E. coli expressing TmpC revealed incorporation of the fatty acid into the antigen. The antigen was overproduced, purified to near homogeneity and used in an enzyme-linked immunosorbent assay (ELISA) to evaluate its potential for the serodiagnosis of syphilis. Although all sera from untreated secondary syphilis patients were reactive in this TmpC ELISA, only a minority of the serum samples from untreated patients in the primary or early latent stage of the disease contained significant anti-TmpC antibodies. To study the influence of the lipid moiety on the antigenic properties of the TmpC, TmpA, and TpD lipoproteins, plasmids encoding nonlipidated forms of these antigens were constructed. In addition, a plasmid expressing a lipidated form of the otherwise non-lipid-modified antigen TmpB was constructed. Immunization and absorption experiments with these lipidated and nonlipidated antigens showed that antibodies against the lipid moiety of lipoproteins could not be detected on immunoblots, neither in sera from infected rabbits nor in sera from animals immunized with the lipoproteins. In addition, we were unable to demonstrate cross-reactivity between antibodies against the T. pallidum lipoproteins and those reactive to the Venereal Diseases Research Laboratories test, suggesting that antibodies reactive to the Venereal Diseases Research Laboratories test are unrelated to antilipoprotein antibodies.

Study of the TPI test in clinical syphilis. 1. Untreated early symptomatic syphilis.

IT PREVIOUSLY has been reported * that the Treponema pallidum immobilization (TPI) test may be nonreactive during the primary and secondary stages of syphilis. The lipid antigen serologic tests for syphilis, e. g., Kahn, Kolmer, VDRL slide, Rein-Bossak, also may be negative in the presence of dark-field-positive lesions of primary syphilis, but are invariably reactive during the secondary stage of syphilis. 4 This study of previously untreated dark-field-positive primary and secondary syphilis patients was undertaken to compare the sensitivity of the TPI test, as modified by Portnoy, Harris, and Olansky, 5 in these stages of syphilis with that of the VDRL slide flocculation quantitative and Rein-Bossak slide flocculation quantitative tests. CLINICAL MATERIAL Thirty patients with dark-field-positive primary syphilis and 20 patients with dark-field-positive secondary syphilis, who had no history of previous treatment for syphilis at any time, were studied. These were patients either of the AtlantaFulton