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PubMed1988

Chlamydia trachomatis among sexually active teenage girls. Lack of correlation between chlamydial infection, history of the patient and clinical signs of infection.

Cultures for Chlamydia trachomatis were obtained from 1012 teenage girls attending an adolescence clinic mainly for family planning; C. trachomatis was isolated from 174 (17.2%). The proportion of chlamydia-positive girls varied between 15.7% and 28.5% depending whether or not there were symptoms and signs of infection. Neither the history nor the finding at pelvic examination offered conclusive evidence for or against the presence of an infection with C. trachomatis. Of the chlamydia-positive, untreated, asymptomatic girls, 17.5% developed symptoms of a genital infection within 3 months. There was a statistically significant difference in the proportion of positive cultures by the two investigators, suggesting that the procedure for specimen collection is of great importance.

Adolescent↗
PubMed1987

Chlamydia trachomatis isolation in women attending a VD clinic in Auckland, New Zealand.

Chlamydia trachomatis was isolated from 120 of 504 women (24%) attending a VD clinic at Auckland Hospital. Epidemiological correlates indicated a sexual mode of transmission. The only symptom of significance was lower abdominal pain. Cervicitis was more common in women with chlamydia, especially if they were on hormonal contraceptives. Chlamydia was isolated more commonly in women with gonorrhoea (52%) and genital warts (37%). The high incidence of asymptomatic and unsuspected infection emphasizes the need for routine chlamydial culture in VD clinics.

Adolescent↗
PubMed1990

Chlamydia trachomatis--role in tubal infertility.

The prevalence of humoural IgG and IgM antibodies to Chlamydia trachomatis was determined in 110 infertile women and compared to 87 healthy pregnant women without any known fertility problem. Overall antibodies to chlamydia were detected in 45% of infertile women. Antibodies were found in significantly more patients with tubal factor infertility (65%) than in women whose infertility was due to other causes (22%) (p less than 0.005). These findings are consistent with the hypothesis that C. trachomatis is a major cause of tubal factor infertility. In addition the prevalence of antibody in patients with other sexually transmitted diseases (STD), pelvic inflammatory disease and confirmed chlamydia cases were evaluated. Within this miscellaneous high risk group of patients, chlamydial antibodies were detected commonly, ranging from 19-72%.

Adult↗
PubMed1979

Experimental acute salpingitis in grivet monkeys provoked by Chlamydia trachomatis.

Chlamydia trachomatis is a common cause of sexually transmitted diseases. Recently it has been shown that chlamydiae are also responsible for complications to such lower genital tract infections. In this study, isolates of C. trachomatis from the fallopian tubes of patients with acute salpingitis were inoculated direct into the fallopian tubes of two, and through the cervical canal into the uterine cavity of one grivet monkey. The experimental infections resulted in a self-limited acute salpingitis in the three animals. C. trachomatis was recovered from the monkeys 2 and 3 weeks post inoculation. As found at laparotomy, the infected tubes were swollen and reddened, and there was watery exudate in the abdominal ostia. Microscopically, cellular infiltrates--mainly lymphocytes--were seen in the mucosa, muscularis and subserosa of the tubes. Serologically, a primary antibody response with an IgM to IgG conversion was found. Salpingitis did not occur in a control monkey inoculated in the tubes with a medium lacking Chlamydia. The histological changes in the fallopian tubes of the infected monkeys were reminiscent of those described as being characteristic of "gonococcal" salpingitis in man. The fulfilment of Koch's postulates in the animal model used adds to the earlier evidence that C. trachomatis is capable of causing acute salpingitis in humans.

Acute Disease↗
PubMed1998

Sexually active adolescents and young adults: a high-risk group for Chlamydia trachomatis infection.

BACKGROUND: The importance of travel as a risk factor for Chlamydia trachomatis infection was evaluated among a series of young people consecutively tested. METHODS: We studied 130 sexually active young subjects, aged 14-25 years, all living in the Rome, Italy, urban area. Ninety-eight females and 32 males attended hospital-based clinics or were the partners of an infected female. About half of these subjects had traveled abroad either for pleasure or for work, mostly to Europe, but also to North America or to Asia, where they admitted to having had casual sex. We used two "gold standard" methods to diagnose infection with C. trachomatis: culture on McCoy cells grown in shell vial, and direct immunofluorescence with monoclonal antibodies. Subjects were considered infected when at least one test was positive. RESULTS: Thirty-nine of 130 (30%) subjects were asymptomatic, and 27/130 (20.8%) subjects were infected with Chlamydia trachomatis, of whom 6/25 (24%) asymptomatic females and 3/14 (21.4%) asymptomatic males were infected. Among teen-aged (ages 14-19) youngsters with more than one sex partner, international travel was an additional significant risk factor for C. trachomatis infection (p<.02; OR 20; 95% CI 1.47-40%). Urethritis/cystitis and vaginal pathology/discharge were the prevalent manifestations of illness among the females, while urethritis was the only clinical condition found in the males. CONCLUSION: In a series of young subjects, travel abroad, sex with more than one partner, and teen age, combined together, were significant risk factors for the acquisition of Chlamydia trachomatis genitourinary infection.

Adolescent↗
PubMed1990

[Epidemiological survey of Chlamydia trachomatis infections from 1984 to 1988].

We continued the epidemiological survey on sexually transmitted disease due to Chlamydia trachomatis in Okayama Prefecture. The results obtained from October 1984 to October 1988 are briefly summarized in this paper. 1) Sera from outpatients with suspected chlamydial infections were tested for IgG antibodies to Chlamydia trachomatis by the microplate immunofluorescence antibody technique (MFA). Fifty five percent of the male and 61% of the female patients were positive for anti C. trachomatis IgG. 2) Clinical swabs obtained from 735 males and 251 females were examined for Chlamydia trachomatis antigens by the isolation method and direct immunofluorescence tests (DFA) were carried out simultaneously. C. trachomatis was recovered from 34% of the male and 22% of the female patients. 3) The age structure of the female patients was younger than the male patients. Female patients under 29 years of age were 57% of all female antigen-positive cases.

Adult↗
PubMed1994

[Positive rates of Neisseria gonorrhoeae and Chlamydia trachomatis on pharynx and rectum of patients with gonococcal or chlamydial genital infections].

In an attempt to know the applicability of non-cultural detection technique for N. gonorrhoeae and C. trachomatis on pharyngeal and rectal swabs, the swabs taken from N. gonorrhoeae- and C. trachomatis-free subjects were tested by Gonozyme, Chlamydiazyme, Ideia Chlamydia, Gen-Probe and Gen Probe Pace 2. As N. gonorrhoeae- and C. trachomatis-free subjects, the castrated males older than age 70, with known prostate cancer treated at least for 6 months with anti-androgens who were seronegative for C. trachomatis and had a history of Ofloxacin treatment in the last 3 months and whose pharyngeal and rectal swabs were negative for N. gonorrhoeae, were subjected for study. The false negative rates were for N. gonorrhoeae from the pharynx by Gonozyme 57.7%, by Gen-Probe 0%, by Gen-Probe Pace 2 0%, from rectum by Gonozyme 0%, by Gen-Probe 0% by Gen-Probe Pace 2 0%, for C. trachomatis from pharynx by Chlamydiazyme 93.8%, by Ideia Chlamydia 8.3%, by Gen-Probe 0%, by Gen-Probe Pace 2 0%, from rectum by Chlamydiazyme 94.4%, by Ideia Chlamydia 70.9%, by Gen-Probe 20.0% and by Gen-Probe Pace 2 0%. To investigate the incidence of pharyngeal and rectal infection by N. gonorrhoeae among the patients with gonococcal genital infection, as well as pharyngeal and rectal infection by C. trachomatis among the patients with chlamydial genital infection, pharyngeal and recal swabs obtained from the patients with genital infection by N. gonorrhoeae or C. trachomatis were tested by Gen-Probe Pace 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2003

[Analysis of an antigen in Chlamydia trachomatis infected-cell extract which reacts with sera of patients with C. trachomatis infection].

To find a new marker for sero-diagnosis of Chlamydia trachomatis infection, Western blot (WB) method was performed by using C. trachomatis infected HeLa229 cell extract (L2-ext) as antigen. Two series of sera of patients with pneumonia or cervicitis (4 sera each) were used for investigation and analysis of a band which fades earlier than others depending on weeks or antibody levels after therapeutic treatment. A 17 KDa band was found which tended to fade gradually, but did not completely disappear within the period of investigation. The band was also detected in sera of patients with cervicitis diagnosed by detection of C. trachomatis organisms (IDEIA-PCE Chlamydia (IDEIA) or Clearview test were positive at first visit to the clinic). Ten anti-C. pneumoniae antibody positive sera and five anti-Mycoplasma pneumoniae antibody positive sera were also tested as controls. The result was that a 17 KDa band was detected in 20 of 25 sera (80%) with IDEIA positive. 18 of 33 patients (54.5%) with Clearview positive-, and 12 of 16 (75%) sera with both tests positive. No band was found in the control sera. The frequency of antibody against 17 KDa antigen was almost completely identical with that obtained by microimmunofluorescence test and Peptide-Chlamydia-IgG test. These results show that a 17 KDa band may be used as a marker for detection of C. trachomatis antibody by the WB method. The antigen could be precipitated with salting out from the L2-ext with 60% saturation of ammonium sulfate of Hofmeister's method and it was digested with proteinase K. From the result of the amino acid sequence analysis, it was found that 17 KDa protein is the human nucleoside diphosphate kinase B.

Antibodies, Bacterial↗
PubMed1997

The microbicidal agent C31G inhibits Chlamydia trachomatis infectivity in vitro.

Safe and effective vaginal microbicidal compounds are being sought to offer women an independent method for protection against transmission of sexually acquired pathogens. The purpose of this study was to examine the efficacy of two formulations of one such compound, C31G, against Chlamydia trachomatis serovar E alone, its host epithelial cell (HEC-1B) alone, and against chlamydiae-infected HEC-1B cells. Preexposure of isolated, purified infectious chlamydial elementary bodies (EB) to C31G, at pHs 7.2 and 5.7, for 1 h at 4 degrees C resulted in reduced infectivity of EB for HEC-1B cells. Examination of the C31G-exposed 35S-EB on sodium dodecyl sulfate-polyacrylamide gel electrophoresis autoradiographs and by Western blotting revealed a C31G concentration-dependent and pH-dependent destabilization of the chlamydial envelope, resulting in the release of chlamydial lipopolysaccharide and proteins. Interestingly, when the host human genital columnar epithelial cells were infected with chlamydiae and then exposed to dilute concentrations of C31G which did not alter epithelial cell viability, chlamydial infectivity was also markedly reduced. C31G gained access to the developing chlamydial inclusion causing damage to or destruction of metabolically active reticulate bodies as well as apparent alteration of the inclusion membrane, which resulted in premature escape of chlamydial antigen to the infected epithelial surface. These studies show that the broad-spectrum antiviral and antibacterial microbicide C31G also has antichlamydial activity.

Anti-Bacterial Agents↗
PubMed2006

Intranasal vaccination with a secreted chlamydial protein enhances resolution of genital Chlamydia muridarum infection, protects against oviduct pathology, and is highly dependent upon endogenous gamma interferon production.

There is currently no licensed vaccine against Chlamydia trachomatis, the leading cause of sexually transmitted bacterial disease worldwide. Conventional vaccination attempts using surface-exposed chlamydial antigens have achieved only partial success. We have employed a novel vaccination strategy using a secreted protein, chlamydial protease-like activity factor (CPAF), which has been shown to degrade host major histocompatibility complex transcription factors and keratin-8 and therefore may allow immune evasion and establishment of a productive infection. Intranasal immunization using recombinant CPAF (rCPAF) plus interleukin-12 (IL-12) (rCPAF+IL-12 immunization) was used to assess the protective immunity against genital Chlamydia muridarum infection in BALB/c mice. rCPAF+IL-12 immunization induced robust gamma interferon (IFN-gamma) production and minimal IL-4 production by splenocytes upon in vitro recall with rCPAF. The total and immunoglobulin G2a (IgG2a) anti-rCPAF antibody levels in serum were significantly elevated after rCPAF+IL-12 vaccination, as were the total antibody, IgG2a, and IgA levels in bronchoalveolar lavage and vaginal fluids when the animals were compared to animals that received rCPAF alone. rCPAF+IL-12-vaccinated mice displayed significantly reduced bacterial shedding upon chlamydial challenge and accelerated resolution of infection compared to mock-immunized (phosphate-buffered saline) animals. Moreover, rCPAF+IL-12-immunized animals exhibited protection against pathological consequences of chlamydial infection, including the development of hydrosalpinx and oviduct dilatation. This vaccination regimen also reduced the development of fibrosis and the influx of neutrophils into the upper genital tract when the animals were compared to mock-immunized (phosphate-buffered saline) animals after bacterial challenge. rCPAF+IL-12-mediated resolution of the bacterial infection and protection against Chlamydia-induced inflammatory disease were highly dependent on endogenous IFN-gamma production. Together, these results demonstrate that secreted chlamydial antigens may be novel vaccine candidates to induce protective immunity.

Adjuvants, Immunologic↗
PubMed1988

Ultrastructural study of endocytosis of Chlamydia trachomatis by McCoy cells.

The entry of Chlamydia trachomatis into McCoy cells (fibroblasts) was studied by transmission electron microscopy. On adsorption of elementary bodies (EBs) to host cells at 37 degrees C, the EBs were bound primarily to preexisting cell-surface microvilli. They were also observed in coated pits located at the bases of the microvilli and along smooth surfaces of the host cells and were internalized within coated vesicles at this temperature. Postembedding immunogold labeling on Lowicryl thin sections with anti-clathrin antibody as the primary reagent revealed the gold marker localized in pits and vesicles containing chlamydiae. Some EBs were present in smooth-surfaced invaginations at or near the bases of microvilli and in vesicles devoid of distinguishable coat material. A similar entry process was observed with centrifugation-assisted inoculation of EBs onto the McCoy cells. Individual EBs were initially internalized into tightly bound endocytic vesicles. However, within 1 to 3 h postinfection, multiple C. trachomatis EBs were observed in large, loosely bound vesicles. Evidence suggests that vesicles containing C. trachomatis may have fused with one another early in the infectious process. These results indicate that chlamydiae can exploit the specific process of adsorptive endocytosis for entry into host cells and for translocation to a given intracellular destination, which may be different for each species.

Animals↗
PubMed1988

Gamma interferon-mediated cytotoxicity related to murine Chlamydia trachomatis infection.

After infection with the mouse pneumonitis agent (MoPn; murine Chlamydia trachomatis), heterozygous (nu/+) but not nude athymic (nu/nu) mice produced enhanced amounts of gamma interferon (IFN-gamma) in vitro in response to MoPn antigen that exhibited cytotoxic activity when added to host cells already infected with chlamydiae. Antibody-complement lysis showed the cytotoxic activity to be dependent, at least in part, on L3T4+ T cells for production. The cytotoxic responses were directed primarily against Chlamydia-infected target cells, but a second type of toxicity was demonstrable against uninfected target cells after treatment of the generating cell population with anti-Lyt-2 antibody plus complement at certain time points after infection. This additional nonspecific cytotoxic activity was presumably due to a second factor (factor X) acting in concert with IFN-gamma. Lyt-2+ cells, however, also were shown to play a role in IFN-gamma production and cytotoxicity directed against infected targets at later time points after infection. Neutralization of IFN-gamma in the samples containing cytotoxic activity abrogated the cytotoxicity against both infected and uninfected targets, but cloned murine IFN-gamma exhibited toxicity in a dose-dependent manner only against infected target cells. The data provides evidence that cytotoxicity against infected targets is due to antigen-specific induction of IFN-gamma, but other cytokine activity, most demonstrable after removal of Lyt-2.2+ cells and cytotoxic to uninfected targets, also is present.

Animals↗
PubMed1991

Sequence analysis of the major outer membrane protein gene of Chlamydia pneumoniae.

Compared with the major outer membrane proteins (MOMPs) of the other chlamydial species, the Chlamydia pneumoniae MOMP appears to be less antigenically complex, and as determined by immunoblot analysis, it does not appear to be the immunodominant antigen recognized during infection. Nucleotide sequence analysis of the C. pneumoniae MOMP gene (ompA) revealed that it consisted of a 1,167-base open reading frame with an inferred 39,344-dalton mature protein of 366 amino acids plus a 23-amino-acid leader sequence. A ribosomal-binding site was located in the 5' upstream region, and two stop codons followed by an 11-base dyad forming a stable stem-loop structure were identified. This sequence shares 68 and 71% DNA sequence homology to the Chlamydia trachomatis serovar L2 and Chlamydia psittaci ovine abortion agent MOMP genes, respectively. Interspecies alignment identified regions, corresponding to the variable domains, which share little sequence similarity with the other chlamydial MOMPs. All seven cysteines conserved in the C. trachomatis and C. psittaci MOMPs, which are involved in the formation of disulfide cross-linkages, are found in the C. pneumoniae MOMP.

Amino Acid Sequence↗
PubMed1993

Roles of Ca2+ and F-actin in intracellular aggregation of Chlamydia trachomatis in eucaryotic cells.

The effect of intracellular free Ca2+ ([Ca2+]i) on the intracellular aggregation of Chlamydia trachomatis serovars L2 and E in McCoy and HeLa cells is investigated. Loading the cells with the Ca2+ chelator MAPT/AM (1,2-bis-5-methyl-amino-phenoxylethane-N,N-n'-tetra-acetoxymethyl acetate), thereby decreasing the [Ca2+]i from 67 to 19 nM, decreased the number of cells with a local aggregation of chlamydiae in a dose-dependent manner. Neither the attachment nor the uptake of elementary bodies (EBs) was, however, affected after depletion of Ca2+ from the cells. There was no significant difference in the level of measured [Ca2+]i between infected and uninfected cells. Reducing the [Ca2+]i also significantly inhibited chlamydial inclusion formation. Differences in the organization of the actin filament network were observed in response to [Ca2+]i depletion. In Ca(2+)-depleted cells, where few EB aggregates were formed, few local accumulations of F-actin were observed in the cytosol. These results suggest that the aggregation of EBs in eucaryotic cells requires a normal homeostasis of intracellular Ca2+. By affecting F-actin reorganization and putatively certain Ca(2+)-binding proteins, [Ca2+]i plays a vital role in the infectious process of chlamydiae.

Actins↗
PubMed1994

Role for CD8+ T cells in antichlamydial immunity defined by Chlamydia-specific T-lymphocyte clones.

The role of CD8+ T cells in antichlamydial immunity was investigated in a murine model of chlamydial genital infection by using T-cell clones generated against the Chlamydia trachomatis agent of mouse pneumonitis (MoPn). Two CD8+ T-cell clones tested (2.1F and 2.14-9) were chlamydia antigen specific and MHC restricted and reacted against MoPn as well as the Chlamydia psittaci agent of guinea pig inclusion conjunctivitis and C. trachomatis serovar E, suggesting the recognition of a genus-specific antigen. Upon adoptive transfer into persistently MoPn-infected nu/nu mice, 55.6% of the recipients of clone 2.1F (15 of 27) resolved the infection but recipients of clone 2.14-9 did not. The ability to resolve the MoPn infection correlated with the capacity of clone 2.1F to elaborate a combination of gamma interferon and tumor necrosis factor alpha. The results suggested that in addition to CD4+ T cells, CD8+ T cells may also contribute to antichlamydial T-cell immunity in vivo.

Animals↗
PubMed1995

Role of CD8 T cells in primary Chlamydia infection.

The role of CD4 and CD8 T cells in primary Chlamydia trachomatis pneumonia was investigated by using in vivo depletion techniques to eliminate T-cell populations. Reduction of either CD4 T cells or CD8 T cells caused a significant increase in organism burden in the lungs, as measured by both quantitative culture and detection of chlamydial antigen on day 14 postinfection. Chlamydia-specific antibody levels in plasma or antigen-induced gamma interferon (IFN-gamma) production by spleen cells was dramatically reduced by depletion of CD4 cells. The reduction in IFN-gamma achieved by depletion of CD8 cells did not reach statistical significance. In the survival studies, depletion of CD4 cells led to a significant increase in mortality. Although there was a trend toward higher mortality, depletion of CD8 cells did not significantly increase mortality. The role of CD8 T cells in host defense was clarified in studies using beta 2-microglobulin-deficient (major histocompatibility class I antigen-deficient, C1D) mice which are defective in CD8 T-cell function. In this model, a significant increase in organism burden was seen during infection in C1D mice compared with that C57BL/6 controls and a significant increase in mortality was observed as well. However, surviving C1D mice were able to clear the infection by day 34. C1D mice had increased numbers of CD4 T cells in both the spleen and the lungs during infection compared with those of C57BL/6 controls. IFN-gamma in C57BL/6 mice was produced by both CD4 and CD8 cells. Thus, there is a protective role for both CD4 and CD8 cells in host defense against Chlamydia infection, but the former appear to be dominant.

Animals↗
PubMed1995

The inflammatory cytokine response to Chlamydia trachomatis infection is endotoxin mediated.

Chlamydia trachomatis is a major etiologic agent of sexually transmitted diseases. Although C. trachomatis is a gram-negative pathogen, chlamydial infections are not generally thought of as endotoxin-mediated diseases. A molecular characterization of the acute immune response to chlamydia, especially with regard to the role of its lipopolysaccharide (LPS), remains to be undertaken. We extracted 15 mg of LPS from 5 x 10(12) C. trachomatis elementary bodies (EB) for analysis of structure and biological activity. When methylated lipid A was subjected to high-pressure liquid chromatography followed by mass spectrometry, the majority of the lipid A was found to be pentaacyl. The endotoxin activities of whole C. trachomatis EB and purified LPS were characterized in comparison with whole Salmonella minnesota R595 and with S. minnesota R595 LPS and lipooligosaccharide from Neisseria gonorrhoeae. Both C. trachomatis LPS and whole EB induced the release of tumor necrosis factor alpha from whole blood ex vivo, and C. trachomatis LPS was capable of inducing the translocation of nuclear factor kappa B in a Chinese hamster ovary fibroblast cell line transfected with the LPS receptor CD14. In both assays, however, C. trachomatis was approximately 100-fold less potent than S. minnesota and N. gonorrhoeae. The observation that C. trachomatis is a weak inducer of the inflammatory cytokine response correlates with the clinical observation that, unlike N. gonorrhoeae infection, genital tract infection with C. trachomatis is often asymptomatic. The ability of specific LPS antagonists to completely inhibit the tumor necrosis factor alpha-inducing activity of whole C. trachomatis EB suggests that the inflammatory cytokine response to chlamydia infection may be mediated primarily through LPS. This implies that the role of other surface protein antigens, at least in terms of eliciting the proinflammatory cytokine response, is likely to be minor.

Antigens, CD↗
PubMed1996

Vesicular interactions of the Chlamydia trachomatis inclusion are determined by chlamydial early protein synthesis rather than route of entry.

Chlamydiae replicate intracellularly within a vacuole that has recently been characterized as intersecting an exocytic pathway. One of the initial events during chlamydial infection is the expression of a chlamydial early gene product(s) that effectively isolates the inclusion from the endocytic-lysosomal pathway and makes it fusogenic with sphingomyelin-containing exocytic vesicles. Associated with this change in vesicular interaction is the delivery of the vacuole to the peri-Golgi region of the host cell. Inhibition of chlamydial early transcription or translation causes Chlamydia trachomatis-containing vesicles to remain dispersed throughout the cytoplasm, where they eventually fuse with lysosomes. Chlamydiae that have been internalized by Fc-mediated endocytosis also avoid lysosomal digestion by a mechanism that requires chlamydial protein synthesis. These results suggest that the vesicular interactions of the chlamydial inclusion are defined by parasite-directed modification of the endocytic vesicle rather than by the route of internalization.

Bacterial Proteins↗