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PubMed1982

Detection of circulating antigens of Chlamydia trachomatis by counterimmunoelectrophoresis.

An increasing number of reports on Chlamydia trachomatis pneumonia in infancy has recently been published in the literature. The demonstration of the etiologic agent depends, however, on laborious culture procedures and serological techniques. Based on the observation of a cross-reaction between certain Acinetobacter species and chlamydiae, the detection of chlamydial antigens in sera of 5 infants with distinctive clinical features of a pneumonia due to Chlamydia trachomatis was performed with antisera to Acinetobacter by the counterimmunoelectrophoresis (CIE) technique.

Acinetobacter↗
PubMed1985

Prevalence of Chlamydia trachomatis in the pregnant cervix.

To determine the prevalence of infection and colonization with Chlamydia trachomatis in pregnant women of low socioeconomic status, 363 women (age range 15 to 48 years; median age 24) were screened. Cultures for C trachomatis were obtained prospectively. Chlamydia trachomatis was recovered from 16.8% of the patients. The incidence of infection ranged from 18.4% in the group age 15 to 19 through 13% in the group age 30 to 39, to 0% in the 40 and older group. Thus, in the population studies, C trachomatis was found more commonly in the younger age groups. The high isolation rates seen suggest that routine screening and treatment may be warranted to prevent spread of C trachomatis infections to sexual partners and neonates.

Adolescent↗
PubMed2000

Identification and mapping of sigma-54 promoters in Chlamydia trachomatis.

The first sigma(54) promoters in Chlamydia trachomatis L2 were mapped upstream of hypothetical proteins CT652.1 and CT683. Comparative genomics indicated that these sigma(54) promoters and potential upstream activation binding sites are conserved in orthologous C. trachomatis D, C. trachomatis mouse pneumonitis strain, and Chlamydia pneumoniae (CWL029 and AR39) genes.

Base Sequence↗
PubMed2000

Touchdown enzyme time release-PCR for detection and identification of Chlamydia trachomatis, C. pneumoniae, and C. psittaci using the 16S and 16S-23S spacer rRNA genes.

Three touchdown enzyme time release (TETR)-PCR assays were used to amplify different DNA sequences in the variable regions of the 16S and 16S-23S spacer rRNA genes specific for Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci as improved tests for sensitive diagnosis and rapid species differentiation. The TETR-PCR protocol used 60 cycles of amplification, which provided improved analytical sensitivity (0.004 to 0.063 inclusion-forming unit of Chlamydia species per PCR). The sensitivity of TETR-PCR with primer set CTR 70-CTR 71 was 96.7%, and the specificity was 99.6%, compared to those of the AMPLICOR PCR for the detection of C. trachomatis in vaginal swab samples. TETR-PCR for C. pneumoniae with primer set CPN 90-CPN 91 was 90% sensitive and 93.3% specific compared with a nested PCR with primer set CP1/2-CPC/D for clinical respiratory samples. TETR-PCR for C. psittaci with primer set CPS 100-CPS 101 showed substantial agreement with cell culturing (kappa, 0.78) for animal tissue samples. Primer sets were then combined into a single multiplex TETR-PCR test. The respective 315-, 195-, and 111-bp DNA target products were precisely amplified when DNA from each of the respective Chlamydia species or combinations of them was used. Multiplex chlamydia TETR-PCR correctly identified one strain of each of the 15 serovars of C. trachomatis, 22 isolates of C. pneumoniae, and 20 isolates of C. psittaci. The primer sets were specific for each species. No target products were amplified when DNA from C. pecorum or a variety of other microorganisms was tested for specificity. TETR-PCR with primers selected for specific sequences in the 16S and 16S-23S spacer rRNA genes is a valuable test that could be used either with individual primers or in a multiplex assay for the identification and differentiation of Chlamydia species from culture isolates or for the detection of chlamydiae in clinical samples.

Base Sequence↗
PubMed1987

Unrecognized high prevalence of Chlamydia trachomatis cervical infection in an isolated Alaskan Eskimo population.

Chlamydia trachomatis genital infections often go unrecognized where specific culture diagnosis is not easily accessible. We studied the prevalence and clinical correlates of C trachomatis in a geographically isolated Alaskan Eskimo population with a high rate of gonorrhea but for whom specific chlamydial diagnosis had never been available. Using a direct immunofluorescent stain of endocervical secretions, we screened 493 women (52% of all women of reproductive age) when they presented to regional health facilities during the year-long study period. Chlamydia trachomatis was identified in 23% (114/493), including 39% (31/80) of teenagers, 30% (34/115) of prenatal patients, 47% (7/15) of pregnant teens, and 40% (8/19) of women with pelvic inflammatory disease. Genital symptoms, clinical signs, and the presence of concomitant gonorrhea were ineffective means of identifying chlamydial infection. This study demonstrates the successful use, and public health importance, of nonculture direct testing to document the unrecognized high prevalence of C trachomatis infection where culture diagnosis is not available.

Adolescent↗
PubMed1993

Evaluation of Pharmacia Chlamydia EIA for diagnosis of genital infections caused by Chlamydia trachomatis.

A new enzyme-immunoassay test (EIA), Pharmacia Chlamydia EIA, was evaluated in comparison with isolation in cell culture for the diagnosis of genital infections caused by Chlamydia trachomatis. Endocervical and endourethral specimens were collected from 913 patients (875 female and 38 male patients respectively). Sensitivity, specificity, positive predictive and negative predictive values for this test were 89.4%, 99.2%, 85.8% and 99.4% respectively. Where discrepancies between the 2 techniques occurred, the remainder of the EIA buffer was stained for chlamydial antigen by direct immunofluorescence using the Syva Microtrak Chlamydia trachomatis Direct Specimen Test. Laboratory strains of various micro-organisms that may be present in genital specimens did not cross react with the EIA test except for Staphylococcus aureus and Group B Streptococcus at very high concentrations. The Pharmacia Chlamydia EIA is suitable for a laboratory which handles a large number of chlamydial specimens daily. However, when interpreting EIA results, the prevalence of chlamydial infection in the patient population should be established. At present, EIA tests are unsuitable as the only test for chlamydial diagnosis in low risk populations.

Bacteriological Techniques↗
PubMed1999

Chlamydia trachomatis nucleic acids can be found in the synovium of some asymptomatic subjects.

OBJECTIVE: The recent identification of antigens or nucleic acids of infectious agents in the joints of patients with reactive arthritis has raised questions about whether chlamydial or other infectious agent nucleic acids are also present in normal joints. We had the opportunity to study synovium from 30 asymptomatic volunteer subjects by use of polymerase chain reaction (PCR) for attempted identification of Chlamydia and other infectious agents. METHODS: All subjects had blind needle synovial biopsies with the Parker-Pearson needle. DNA was extracted and PCR performed using primers for Chlamydia trachomatis, Chlamydia pneumoniae, Borrelia burgdorferi, and pan bacterial 16S ribosomal RNA (rRNA). RESULTS: Two subjects were identified with nucleic acid for the 16S rRNA gene of C trachomatis. All other PCR reactions were negative except for the pan bacterial 16S rRNA in the C trachomatis-positive subjects. Both subjects, although symptom free, had some evidence of synovial reaction. CONCLUSION: C trachomatis appears to occasionally be disseminated to joints without producing overt disease.

Adult↗
PubMed1992

Evaluation of a chemiluminometric immunoassay for detection of Chlamydia trachomatis in the urine of male and female patients.

A chemiluminometric immunoassay (Magic Lite Chlamydia) for detection of Chlamydia trachomatis antigens in first-void urine samples was compared with cell culture using urogenital swabs from 221 men and 242 women. The rate of isolation of Chlamydia trachomatis was 23.5% in men, nearly 80% of whom had symptoms of urethritis, and 8.3% in women, in whom both cervix and urethra samples were tested. In urine sediments from men and women respectively the chemiluminometric assay showed a sensitivity of 80.8% and 70%, a specificity of 97% and 95%, a positive predictive value of 89.4% and 58.3%, and a negative predictive value of 94.3% and 97.2%. Discrepancies between results obtained with the chemiluminometric assay and cell culture were resolved using two polymerase chain reaction techniques to test urogenital samples. The detection of Chlamydia trachomatis in urine samples with the chemiluminometric assay was confirmed to be superior for screening symptomatic men with urogenital infections than women as a lower prevalence population.

Adolescent↗
PubMed1986

In vitro activity of the two new 4-quinolones A56619 and A56620 against Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum and Gardnerella vaginalis.

The in vitro activity of tetracycline, ciprofloxacin and two recently developed 1-aryl-fluoroquinolones, A56610 and A56620, was tested against 65 beta-lactamase-negative and 35 beta-lactamase-positive Neisseria gonorrhoeae strains, 12 Chlamydia trachomatis, 50 Mycoplasma hominis, 28 Ureaplasma urealyticum and 50 Gardnerella vaginalis strains. In the case of Chlamydia trachomatis and Mycoplasma hominis both the MIC and the MBC were determined. The MIC90 of ciprofloxacin for Neisseria gonorrhoeae was 0.008 microgram/ml and of A56619 and A56620 less than or equal to 0.03 microgram/ml. No difference was observed between the activity against beta-lactamase-negative and beta-lactamase-positive strains. The MIC90 values of of ciprofloxacin and A56620 for Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum were identical, the values being 2 micrograms/ml, 1 micrograms/ml and 4 micrograms/ml respectively. The MIC90 of A56619 for Chlamydia trachomatis and Ureaplasma urealyticum was 0.5 micrograms/ml and 1 microgram/ml respectively. The MBC90 values of the three quinolones for Chlamydia trachomatis and Mycoplasma hominis were less than or equal to 2 micrograms/ml. The activity of the quinolones against Gardnerella vaginalis was rather low, the MIC90 being greater than or equal to 4 micrograms/ml. It is concluded that A56619 and A56620 might be useful for single-dose therapy of gonococcal infections.

Anti-Bacterial Agents↗
PubMed2006

Effect of storage temperature on survival of Chlamydia trachomatis after lyophilization.

Lyophilized preparations of Chlamydia trachomatis were made to investigate how well they would survive storage at four relevant incubation temperatures for 1 week and 1 month. Good viability was maintained by storage at either 4 degrees C or 20 degrees C for 1 week. If the ambient temperature is not too high, short-term transportation of C. trachomatis is achievable through lyophilization.

Chlamydia trachomatis↗
PubMed1989

Clinical and laboratory considerations of culture vs antigen assays for detection of Chlamydia trachomatis from genital specimens.

Assays for Chlamydia trachomatis antigen are being increasingly used in lieu of traditional cell culture methods for detection of the organism in patient specimens. While results from these assays are available considerably earlier than are those from culture, the assays have been less sensitive and specific than culture when used in some patient populations. This review summarizes results from investigations into the performance of culture and the two most widely used antigen assays, documents factors that can contribute to false-positive or false-negative results, and, in light of these factors, makes recommendations for the selection of methods for detection of C trachomatis from genital specimens.

Antigens, Bacterial↗
PubMed1991

A heat-labile protein of Chlamydia trachomatis binds to HeLa cells and inhibits the adherence of chlamydiae.

From highly purified elementary bodies (EBs) of Chlamydia trachomatis, we have identified a protein of 38 kDa that selectively binds to monolayer cultures of HeLa cells. This protein, which we have named the chlamydial cytadhesin (CCA), is present on the surface of the EBs of three C. trachomatis serovars (B, E, and L1) that were examined. Localization of the CCA at the surface was confirmed by its ability to be labeled when viable EBs were iodinated and by its absence in preparations from trypsin-treated EBs. Viable EBs, but not heated or trypsin-treated EBs, inhibited the binding of the CCA to HeLa cells, indicating competition for a common receptor on the host cell membrane. A dose-dependent inhibition of adherence of radioactive EBs to HeLa cells was effected by extracts containing the CCA. This inhibition occurred even with extracts prepared from the EB of heterologous serovars. However, no inhibition could be demonstrated with extracts prepared from heat-treated EBs. Heat treatment of the extract resulted in the loss of ability of the CCA to bind to the host cells. HeLa cells preincubated with CCA-containing chlamydial extract showed reduced ability to bind labeled EBs and to develop cytoplasmic inclusions after infection. This protective activity was lost after exposure of the extract to heat. These findings indicate that the CCA is a thermolabile surface-exposed chlamydial adhesin; it may be useful in the development of vaccines for diseases caused by the pathogenic bacterium.

Bacterial Adhesion↗
PubMed2000

Prevalence of Chlamydia trachomatis in young men in north west London.

BACKGROUND: Chlamydia trachomatis is the most common, treatable, bacterial sexually transmitted infection in England and Wales. Among men, chlamydial infection is an important cause of non-gonococcal urethritis, epididymitis, and proctitis. The case for wider screening among women has been accepted by an expert advisory group. In the absence of estimates of the prevalence of infection in men, its potential impact at the population level is difficult to assess. OBJECTIVE: To estimate the prevalence of Chlamydia trachomatis in young men in clinic and community based samples in north west London. METHOD: Cross sectional survey in healthcare centres and general practices in north west London. 1002 males aged 18-35 years, living in north west London, were recruited by staff in occupational health departments, general practices, student health services, and a "well man" clinic and by postal recruitment in four GP practices. The men were tested for C trachomatis using the ligase chain reaction assay on urine samples. The main outcome measure was prevalence of C trachomatis infection in men aged 18-35 years. RESULTS: The overall response rate was 51%. Prevalence of confirmed infection was 1.9% (95% CI: 1.14% to 2.96%) in all men. Best estimated minimum prevalence of infection was 1% (95% CI: 0.58% to 1.50%). Estimated prevalence was highest among men aged over 30 years. CONCLUSIONS: The estimated prevalence among men is commensurate with that described for female populations in London. The results suggest that recruitment of men to screening programmes would be difficult. However, a higher proportion of chlamydial infection may be detected in men than in women by existing approaches to control through genitourinary medicine clinic based case finding and contact tracing. Screening of young women and the contact tracing of the male partners of positive females may be an efficient approach to improving chlamydia control.

Adolescent↗
PubMed1979

[Antibodies against Chlamydia trachomatis in patients with non-gonococcal urethritis and in the healthy Italian population].

The Authors report the results of a study on the prevalence of serum antibodies against Chlamydia trachomatis among patients with non-gonococcal urethritis caused by Chlamydia trachomatis and diagnosed on the basis of the isolation of the microorganism in cell cultures, among patients with non-gonococcal urethritis of unknown etiology and in groups of healthy population, in Italy. The search for antibodies was performed both with complement-fixation tests in micro-titer system, using an antigen prepared from chicken embryo yolk sacs infected with the 6BC strain of Chlamydia psittaci, and with indirect immunofluorescence tests. The indirect immunofluorescence tests were carried out using as antigen the whole chlamydial inclusion developed in IUDR pre-treated McCoy cell cultures, grown on coverslips, and infected with the BU/434 strain of the LGV2 immunotype of Chlamydia trachomatis. The immunofluorescence tests proved to be much more sensitive than the complement fixation tests in detecting the presence of anti-chlamydial antibody both in patients with non-gonococcal urethritis and in the healthy population groups. The percentage of subjects possessing anti-chlamydial antibodies among the healthy population suggests a diffuse circulation of Chlamydia trachomatis infection. The possibility of employing the serological data in the diagnosis of the etiology of non-gonococcal urethritis is briefly discussed.

Adolescent↗
PubMed1998

[Chlamydia trachomatis--a risk for reproductive capacity in women].

BACKGROUND: Chlamydia trachomatis is a bacterium which causes in man among others urogenital infections. So far no data were published pertaining to the herd immunity of the population to this infection in the Czech Republic. The objective of the present investigation was to summarize clinical and laboratory results of examined women and to evaluate the assembled data by statistical methods. Special attention was paid to patients examined on account of infertility. METHODS AND RESULTS: 506 women aged 17-50 years (mean age 28 years) were examined. They were divided into five groups (1-cervicitis, 2-pelvic pain, 3-pregnant, 4-sterile, 5-before UPT). Group 4 (sterile) was further subdivided into three categories (4a IVF on account of tubal sterility, 4b IVF on account of non-tubal sterility and 4c others). With regard to the domicile the women were divided into those residing in Prague and those from other towns and rural areas. In all antigenic examinations of smears from the endocervix were made and serological examinations of specific IgA, IgG antichlamydial antibodies. During collection of the smears the appearance of the cervix; discharge, bleeding and pain on examination were evaluated. For statistical evaluation the chi 2 test was used. In 57% of the women from the whole group positive IgG antibodies were detected suggesting a past or present infection. Differences of antigenic or serological positivity between the five different groups were not statistically significant. In category 4a a significantly higher positivity of IgG (2 alpha < 0.001) of antichlamydial antibodies was found (92% patients) than in categories 4b and 4c. 71% women had complaints during examination. The authors did not find a correlation between antigen- and serum positive women indifferent groups and their domicile. CONCLUSIONS: The results provide evidence of a high herd immunity of the population of the Czech Republic to Chlamyata infection. At the same time they prove that post-inflammatory changes caused by Chlamydia trachomatis are the most frequent cause of occlusion of the oviducts and tubal sterility.

Adolescent↗
PubMedDate not supplied

In vitro activity of rifamycins alone and in combination with other antibiotics against Chlamydia trachomatis.

Rifamycins are highly active against Chlamydia trachomatis, but the possible development of resistance has been of concern. The ability of rifampin, rifamide, and DL473 to induce resistance in chlamydiae and the effect of combinations of antibiotics on chlamydiae were evaluated in tissue culture. When chlamydiae were exposed to stepwise increases in the concentration of rifampin or rifamide, resistance rapidly emerged. Stepwise resistance did not emerge after exposure to DL473, although organisms resistant to one rifamycin were resistant to all three. Single-step emergence of resistance to rifampin or DL473 was also demonstrated. However, these resistant organisms were difficult to maintain in tissue culture. Combinations of ampicillin, erythromycin, or a tetracycline with rifampin or DL473 were neither synergistic nor antagonistic against chlamydiae. However, subinhibitory amounts of erythromycin or oxytetracycline prevented the emergence of resistance to rifampin. Such combinations may prove useful in therapy for chlamydial infections.

Chlamydia trachomatis↗
PubMed2002

Comparison of three commercially available peptide-based immunoglobulin G (IgG) and IgA assays to microimmunofluorescence assay for detection of Chlamydia trachomatis antibodies.

Three commercially available, peptide-based enzyme-linked immunosorbent assay (ELISA) systems (Chlamydia trachomatis IgG and IgA EIA [CT-EIA; Labsystems OY, Helsinki, Finland], SeroCT IgG and IgA [SeroCT; Savyon Diagnostics Ltd., Ashdod, Israel], and Chlamydia trachomatis IgG and IgA pELISA [CT pELISA; Medac, Wedel, Germany]) were evaluated for the detection of serum immunoglobulin G (IgG) and IgA antibodies specific for Chlamydia trachomatis and compared to the "gold standard" assay, the microimmunofluorescence (MIF) assay. Serological responses were analyzed in 149 women aged 20 to 30 years. Cervical swabs obtained from these women were examined for C. trachomatis by PCR, and 43 were found to be positive. The overall seroprevalence rates detected by CT-EIA, SeroCT, CT pELISA, and the MIF assay were 42, 42, 35, and 39%, respectively, for IgG and 7, 7, 3, and 7%, respectively, for IgA. The IgG seroprevalence rates for the PCR-positive women were two to three times higher than those for the PCR-negative women, i.e., 72 versus 29%, 72 versus 29%, 47 versus 26%, and 74 versus 25% for CT-EIA, SeroCT, CT pELISA, and the MIF assay, respectively. After discrepancy analysis, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the IgG assays; for CT-EIA they were 84.7, 98.6, 98.4, and 86.7%, respectively; for CT pELISA they were 71.4, 97.3, 96.2, and 78.3%, respectively; for SeroCT they were 84.7, 98.6, 98.4, and 86.3%, respectively; and for the MIF assay they were 79.2, 83.1, 98.3, and 83.1%, respectively. In conclusion, these peptide-based ELISA systems for the serological detection of C. trachomatis infection performed as well as the MIF assay. Since these tests are less time-consuming, less expensive, and easier to perform than the MIF assay, they might be useful in the serodiagnosis of chlamydial infection.

Adult↗
PubMed1996

Evaluation of verification assays in EIA specimens presumptively positive for Chlamydia trachomatis.

Verification of specimens positive for Chlamydia trachomatis by enzyme immunoassay (EIA) has been recommended when testing low prevalence populations. This study compared direct fluorescent antibody (DFA) and blocking antibody (BLA) verification assays in specimens presumptively positive for C. trachomatis by the Syva Microtrak II EIA. Of 1785 specimens originally tested by EIA, 96 were presumptively positive for C. trachomatis. Verification assays were concordant in 86 specimens (69 positive, 17 negative); nine of the remaining samples gave positive results in a second EIA and one was unresolved. Both verification assays gave some false-negative results. When initial EIA absorbance values were correlated with verified results, all EIA false positive results had absorbances in the low range (less than a three-fold increase over assay cut-off values). Verification of EIA results by both DFA and BLA was effective in detecting false positive results, but confining verification to low-value positive specimens could be considered for cost effective C. trachomatis testing.

Antibodies, Bacterial↗