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PubMed1981

Treponema-specific and antilipoidal 19S(IgM) antibodies in penicillin-treated and untreated rabbits after infection with Treponema pallidum.

The titres of treponema-specific and antilipoidal 19S(IgG) antibodies were determined in rabbits infected intratesticularly with Treponema pallidum. One group of rabbits was treated with penicillin the other served as control. Using different serological tests it was shown that 19S(IgM) antibodies were still detectable eight months after infection at about the same titres in both groups. In contrast, 19S(IgM) antibody titres in patients with syphilis became undetectable within three to six months after penicillin treatment. It is suggested therefore that the rabbit is not a reliable model for studying the effect of penicillin in human T pallidum infections.

Animals↗
PubMed1977

Electron microscopy of lymph nodes of hamsters experimentally infected with Treponema pertenue.

The morphology of lymph node tissue from normal hamsters and from hamsters experimentally infected with Treponema pertenue Gauthier was compared by means of light and electron microscopy. The capsules of the lymph nodes from infected hamsters showed an increased thickness in comparison with those of the non-infected animals. The infected lymph nodes differed from normal lymph nodes by small accumulations of neutrophilic leucocytes in the cortical areas. In addition, the amount of intercellular collagenous matrix present between large elongated cells was greatly increased in lymph nodes from infected animals. Electron microscopy of thin sections of infected lymph nodes showed intercellularly located treponemes in the leucocyte infiltration areas. These regions also showed the increased amounts of the collagenous matrix. Treponemes were occasionally found intracellularly in macrophages. These treponemes did not show their typically helical shape, but were present as spherical forms or cysts.

Animals↗
PubMed1993

Clarithromycin therapy of experimental Treponema pallidum infections in hamsters.

Clarithromycin was shown to be effective therapy for Treponema pallidum infections in hamsters. Clarithromycin therapy was effective when initiated either 1 or 8 days after infection. The delay in initiation of therapy allowed an active infection to develop. The treponemal burden in lymph tissue of treated hamsters was eradicated, as determined by dark-field microscopy and by inoculation of lymph material into susceptible hamsters. Treatments with clarithromycin and the 14-hydroxy metabolite of clarithromycin were equally effective. Therapy with clarithromycin and penicillin was not antagonistic and did not appear to be synergistic when the two drugs were given concurrently. Pharmacokinetic evaluation of clarithromycin in hamsters showed that the doses which produced effective therapy yielded concentrations in serum similar to those routinely achieved in human sera. These findings demonstrate that clarithromycin is effective in treating active or incubating syphilis in the hamster model and could be useful in treating humans.

Animals↗
PubMed1976

Accidental laboratory infection with Treponema pallidum, Nichols strain.

This case report describes a laboratory-acquired infection with Treponema pallidum, Nichols strain. The specific details of the accidental exposure are presented, along with a description of the clinical observations. This infection indicates that the rabbit adapted Nichols strain of T pallidum retains its capability to infect humans. In addition, aerosols of concentrated preparations of these organisms, generated within the laboratory, represent a definite biohazard.

Aerosols↗
PubMed1977

Selective response of lymphocytes from Treponema pallidum-infected rabbits to mitogens and Treponema reiteri.

The in vitro response of peripheral blood lymphocytes from rabbit infected with Treponema pallidum was examined using various mitogens and avirulent Treponema reiteri. For the first 4 weeks after treponemal infection, the response of lymphocytes from syphilitic rabbits to phytohemagglutinin and pokeweed mitogen was markedly reduced in comparison to uninfected controls. Lymphocytes from both groups of rabbits responded normally to class-specific immunoglobulin anti-sera (anti-immunoglobulin M and anti-immunoglobulin G) and T. reiteri.

Animals↗
PubMed1978

Parenteral immunization of pigs against infection with Treponema hyodysenteriae.

Six intravenous injections of formalin-inactivated Treponema hyodysenteriae were given to 8 specific-pathogen-free pigs at 6-day intervals. The 8 vaccinated and 8 control pigs were challenged intragastrically with pure cultures of T hyodysenteriae 7 and 8 days after the last intravenous injection. Clinical signs of swine dysentery were observed in all 8 control pigs, but was observed in only 1 of the immunized pigs. Three control pigs died. These findings suggest that parenteral immunization with T hyodysenteriae provided a marked degree of protection against subsequent intragastric challenge exposure with the homologous isolate of T hyodysenteriae.

Animals↗
PubMed1990

Immune T cells sorted by flow cytometry confer protection against infection with Treponema pallidum subsp. pertenue in hamsters.

The role of cell-mediated immunity against infection with Treponema pallidum subsp. pertenue in humans or experimental animals is unclear. Hamsters injected subcutaneously in the hind paws with 4 x 10(6) unfractionated lymph node cells or enriched lymph node T cells (immunoglobulin negative, Ia negative) from T. pallidum subsp. pertenue-immune hamsters were resistant to challenge with T. pallidum subsp. pertenue. The popliteal lymph nodes of hamsters that received immune cells weighed less and had significantly fewer treponemes than did lymph nodes from hamsters infused with cells from nonimmune donors. Furthermore, recipients of immune T cells failed to develop antitreponemal antibodies 21 days after challenge. Enriched T cells were obtained by flow cytometric separation by using monoclonal anti-Ia antibody 14-4-4s, which identified hamster B cells. Flow cytometric analysis by two-color immunofluorescent staining with anti-hamster-immunoglobulin and monoclonal anti-Ia antibody 14-4-4s confirmed that monoclonal anti-Ia antibody 14-4-4s recognized B cells. In addition, lymph node cells obtained after treatment with anti-Ia monoclonal antibody 14-4-4s and complement were 97% T cells, as determined by monoclonal antibody 20, a hamster T-cell marker. These results demonstrated that highly enriched T cells (immunoglobulin negative, Ia negative) from T. pallidum subsp. pertenue-immune hamsters conferred partial protection on hamsters against infection with T. pallidum subsp. pertenue.

Animals↗
PubMed1991

Ultrastructural aspects of infection with Treponema pallidum subspecies pertenue (Pariaman strain).

OBJECTIVE: To study ultrastructural aspects of infection with Treponema pertenue (Pariaman strain), originating from West Sumatra, Indonesia. MATERIALS AND METHODS: Biopsy material originating from skin lesions in ten young children suffering from early infectious yaws in Indonesia, and rabbit testicular tissue inoculated with T pertenue. Human skin as well as rabbit testicular tissue was examined by means of conventional electron microscopy. RESULTS: In human skin, treponemes were found in interepidermal spaces in 5 out of 10 specimens. In two of five positive specimens, treponemes were also seen in the dermis. In one out of five specimens from rabbit testicular tissue a profusion of treponemes was found lying in the interstitial myxomatous tissue. Microorganisms showed no adhesion to fibroblasts. CONCLUSION: This ultrastructural study of T pertenue demonstrated the scarcity and focal distribution of treponemes in tissue and did not reveal any morphological differences from the Gauthier strain of T pertenue. No differences from the ultrastructure of T pallidum were observed either.

Animals↗
PubMed1979

Simultaneous infection with Treponema pallidum and herpes simplex virus.

Two cases are presented of simultaneous infection with Treponema pallidum and herpes simplex virus. The occasional concurrence of these diseases suggests that all cases of herpes genitalis, including those with negative darkfield examinations and initial nonreactive serologic tests for syphilis, should be followed in two to four weeks by a repeat serologic test for syphilis.

Adult↗
PubMed1982

Effect of route of infection with Treponema pallidum. In vitro cellular response to treponemal antigens.

We investigated how route of infection with Treponema pallidum affects cellular responses of various lymphoid tissues. Lymphoid cells from spleens and lymph nodes of rabbits infected intradermally with T pallidum showed enhanced in vitro responses to treponemal antigens when cultured in autologous rabbit serum. Intravenous infection with T pallidum increased the responsiveness of splenic lymphocytes to T pallidum antigen only during the time of lesion development; lymph node lymphocytes responded throughout the first 30 days of infection, whereas peripheral blood lymphocytes did not respond to treponemal antigens in vitro. Lymphocytes from spleens and peripheral blood of intratesticularly infected rabbits poorly to T pallidum when cultured in autologous serum, but not when cultured in normal serum; however, lymph node lymphocytes from the same rabbits responded normally to T pallidum antigen in either type of serum.

Animals↗
PubMed1994

Flow cytometric analysis of peripheral blood lymphocyte immunophenotypes in persons infected with Treponema pallidum.

To characterize the human immune response to syphilis, we determined the effect of infection with Treponema pallidum on the percentage of the various lymphocyte subpopulations in the peripheral blood of infected and uninfected persons. Monoclonal antibodies labeled with either fluorescein isothiocyanate or phycoerythrin were used to perform dual color analysis on a FACScan with the following markers: CD3 for total T cells, CD4 for T helper cells, CD8 for T suppressor cells, CD19 for B cells, and CD16 plus CD56 for natural killer cells. Lymphocyte immunophenotype results were analyzed by the stage of untreated syphilis and by gender. Although they were within the ranges of the normal distribution of immunophenotypes, the percentages of CD4+ cells were significantly lower (P < 0.001) and those of CD8+ cells were higher (P = 0.03) in patients with syphilis than in the uninfected population. For infected versus uninfected subjects, both women and men, the differences in the mean percentages of CD3+ and CD4+ cells were significant (P < or = 0.05). Significant differences were noted between the sexes in secondary syphilis only in the mean percentages of cells positive for CD3, CD4, CD8, and CD16 plus CD56. Gender had no effect on lymphocyte subpopulations in subjects with primary or latent syphilis. In the control population, significant differences due to gender were observed in the percentages of cells positive for CD3, CD4, and CD16 plus CD56.

B-Lymphocytes↗
PubMed1979

Limited protection of rabbits against infection with Treponema pallidum by immune rabbit sera.

After intradermal infection of rabbits with 3 x 10(6) Treponema pallidum (Melbourne 1 strain) samples of serum were taken at one, two, three, four, and six months after infection. Normal rabbits were passively immunised with these sera, challenged with intradermal doses (10(4), 10(3), 10(2), 10) of T. pallidum, and the latent periods of infection, lesion diameters, and the number of inoculation sites developing into lesions were observed. The sera taken at three, four, and six months reduced the number of intradermal inoculation sites that developed into syphilitic lesions after challenge with 10 T. pallidum. These same three sera also increased the latent period of infection after challenge with 10(4) T. pallidum. The transfer of 50 ml of immune serum per rabbit over a nine-day period before challenge had very little effect on the course of the challenge infection. Only a low level of immunity in rabbits to this strain of T. pallidum appears to be mediated by immune serum but this small degree of protection did increase with time after infection. Enhanced growth of T. pallidum in the serum-recipient rabbits did not occur, thus suggesting that none of the sera was immunosuppressive.

Animals↗
PubMed1984

Studies of rabbit testes infected with Treponema pallidum. III. Immunosuppressive activity of infiltrating mononuclear cells.

When mononuclear cells infiltrating rabbit testes infected with Treponema pallidum were cocultured with autologous or homologous peripheral blood lymphocytes spontaneous stimulation and that induced by concanavalin A were suppressed. The inhibition was not due to the cytotoxic effect of the mononuclear cells or to their interference with the active site of concanavalin A (competitive inhibition). The suppressor activity was present in both T and non-T cells but was not affected by pretreatment of the mononuclear cells with indomethacin, a prostaglandin synthetase inhibitor. The suppressor activity may be intrinsic to the mononuclear cells or acquired by the cells in the testicular environment.

Animals↗
PubMed1982

Mitogenic responses of hamsters infected with Treponema pertenue Lack of correlation with passive transfer of resistance.

Infection of the CB/Ss Lak hamster with Treponema pertenue is characterised by chronic cutaneous lesions and lymph nodes teeming with treponemes. Throughout the course of infection lymph node and spleen cells responded poorly to the mitogens concanavalin A, phytohaemagglutinin, and lipopolysaccharide. This impairment preceded clinical signs of infection and correlated well with the chronicity of framboesial infection. High concentrations of antigen from T pertenue, but not from the non-pathogenic Treponema phagedenis, depressed the mitogenic response of normal lymphoid cells. After framboesial hamsters were treated with penicillin the mitogenic activities of their lymph node and spleen cells were similar to or slightly raised above those of controls. No significant differences were detected among recipients of framboesial immune cells with or without mitogenic activity. Recipients of immune lymph node and spleen cells from penicillin-treated or non-penicillin-treated animals had no cutaneous lesions 21 days after infection and had significantly lower lymph node weights and fewer treponemes per node than recipients of cells from normal penicillin-treated or non-penicillin-treated animals. Since lymphocyte transformation in vitro does not correlate with in-vivo treponemicidal activity, it is not a valid approach to assess the protective immune capacity of the framboesial host.

Animals↗
PubMed1983

Studies of rabbit testes infected with Treponema pallidum. II Local synthesis of antibodies.

Samples of serum and testicular fluid from normal rabbits and those infected with Treponema pallidum were examined for total protein, albumin, IgG, and IgM concentrations. Total protein concentrations were similar in testicular fluid from normal and infected animals but were lower than in serum. The concentrations of individual proteins in serum did not differ substantially between infected and non-infected rabbits. In testicular fluid, however, the concentrations of all three proteins, especially IgM, were greater in infected rabbits. A significantly (p less than 0.02) raised testis-IgM index, together with a higher concentration of anti-treponemal IgM in the infected testicular fluid than in autologous serum, suggests local synthesis of IgM antibodies.

Animals↗
PubMed1991

Role of L3T4+ and 38+ T-cell subsets in resistance against infection with Treponema pallidum subsp. pertenue in hamsters.

The protective immunity conferred by T-cell subsets against infection with Treponema pallidum subsp. pertenue was studied. We demonstrated that hamster T cells can be separated into two subsets by monoclonal antibody (MAb) GK 1.5 (anti-L3T4) and MAb 38. Eighty-five percent of hamster thymocytes were L3T4+ and 87% were 38+ cells; 84% were dual positive for MAbs anti-L3T4 and 38. In the peripheral lymph nodes, however, the L3T4+ and 38+ T cells were mutually exclusive according to two-color immunofluorescence analysis. The two T-cell subsets were found to be functionally distinct according to their secretion of interleukin 2 (IL-2) when stimulated with concanavalin A. The L3T4+ cells secreted IL-2 and had characteristics of T helper cells, while the 38+ cells did not secrete IL-2 and appeared to be T cytotoxic-suppressor cells. Transfer of 4 x 10(6) helper or cytotoxic-suppressor T lymphocytes from T. pallidum subsp. pertenue-immune hamsters protected irradiated naive hamsters against challenge with this subspecies. IL-2 production could still be detected in the irradiated recipients 12 days after irradiation of naive recipients, although at a low level. This suggests that the remaining lymph node cells could support the survival and expansion of the infused cytotoxic-suppressor T cells. No accumulation of macrophages was observed in regional lymph nodes of immune T-cell recipients within 10 days of infection. Instead, there was an influx of polymorphonuclear neutrophils in all animals injected with T. pallidum subsp. pertenue. This report demonstrates that hamster T cells can be separated into two phenotypically and functionally distinct subsets and that both T-cell subsets confer protection against challenge with T. pallidum subsp. pertenue.

Animals↗