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PubMed1998

Performance of the Gen-Probe AMPLIFIED Chlamydia Trachomatis Assay in detecting Chlamydia trachomatis in endocervical and urine specimens from women and urethral and urine specimens from men attending sexually transmitted disease and family planning clinics.

The Gen-Probe AMPLIFIED Chlamydia Trachomatis Assay (AMP CT) uses transcription-mediated amplification and hybridization protection assay procedures to qualitatively detect Chlamydia trachomatis rRNA in urine, endocervical swab, and urethral specimens. The performance of the AMP CT was compared to that of cell culture for endocervical swab and urine specimens from women and urethral and urine specimens from men. Analysis of specimens with discrepant results was performed by a combination of reculture, direct fluorescent-antibody (DFA) staining of specimen sediment, and amplification which targeted a different chlamydial rRNA. A total of 800 urine samples were tested by the AMP CT (607 from women and 193 from men), and 7. 1% were positive for C. trachomatis, with a sensitivity of 91.2% and a specificity of 99.6% upon discrepant analysis. A total of 926 swab specimens were tested by culture and AMP CT (717 endocervical swab specimens and 209 urethral swab specimens from men), and 7.7% were positive for C. trachomatis, with a sensitivity and specificity of 100% upon discrepant analysis. The AMP CT is a sensitive and specific nucleic acid hybridization assay for the detection of C. trachomatis in endocervical swab specimens from women, urethral swab specimens from men, and urine specimens from men and women.

Ambulatory Care Facilities↗
PubMed1998

Detection of Chlamydia trachomatis by the Gen-Probe AMPLIFIED Chlamydia Trachomatis Assay (AMP CT) in urine specimens from men and women and endocervical specimens from women.

Molecular biology-based amplification methods are significantly more sensitive than other methods for the detection of Chlamydia trachomatis. The performance characteristics of the new Gen-Probe AMPLIFIED Chlamydia Trachomatis Assay (AMP CT) with endocervical and urine specimens were compared to those of culture for patients attending two Baltimore City sexually transmitted disease clinics and a clinic for adolescents. AMP CT uses transcription-mediated amplification (TMA) and hybridization protection assay procedures to qualitatively detect C. trachomatis by targeting a 23S rRNA. Discrepant results between culture-negative and AMP CT-positive specimens were resolved by direct fluorescent-antibody staining of sedimented culture transport medium for elementary bodies and by TMA with 16S rRNA as a target. Following discrepant analysis, for 480 female urine specimens AMP CT had a sensitivity of 93.8% and a specificity of 100%. For 464 male urine specimens, the resolved sensitivity and specificity of AMP CT were 95.6 and 98.7%, respectively. For the 479 endocervical swab specimens the sensitivity of AMP CT was 100% and the specificity was 99.5%. Resolved culture sensitivities of AMP CT for female and male swab specimens were 52.3 and 58.9%, respectively. These results demonstrate that AMP CT is highly sensitive for the detection of C. trachomatis in endocervical specimens and in urine specimens from men and women.

Cells, Cultured↗
PubMed1997

Evaluation of 2-SP transport medium for detection of Chlamydia trachomatis and Neisseria gonorrhoeae by two automated amplification systems and culture for chlamydia.

AIMS: To assess the performance of 2-sucrose-phosphate based transport medium (2-SP) for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae by an automated commercial polymerase chain reaction (PCR) and ligase chain reaction (LCR) compared to centrifugation culture on McCoy cells for C trachomatis. Second, to compare both amplification systems for initial diagnostic testing of a low prevalence population for sexually transmitted diseases. METHODS: Four hundred and eighty one consecutive urogenital and conjunctival specimens were examined. All tests were performed on the same specimen collected with a dacron swab and transported in 2-SP medium. Samples that were positive by culture or by both PCR and LCR were considered to be true positives. RESULTS: The prevalences of C trachomatis and of N gonorrhoeae were 2.7% and 0.4%, respectively. PCR had a resolved sensitivity and specificity of 100% and 99.8%, respectively, for C trachomatis, and 100% and 98.9%, respectively, for N gonorrhoeae. LCR was 100% sensitive and specific for both pathogens. The resolved sensitivity of the shell vial assay was 85%. No culture positive sample would have been missed by PCR or LCR. The inhibition rate for PCR was 4.8%. CONCLUSIONS: 2-SP medium proved to be suitable for both PCR and LCR. It is not limited to any one test manufacturer and allows the performance of amplification techniques and viral and chlamydia culture from the same specimen. The LCR was more reliable than PCR on initial testing. However, hands on time is longer, and no amplification control is available for LCR.

Bacteriological Techniques↗
PubMedDate not supplied

The Relationship between chlamydia trachomatis and chlamydia pneumoniae as the cause of neonatal conjunctivitis (ophthalmia neonatorum).

The authors examined 130 newborns and nursery children from September 1999 till May 2003 from the Prague district for the surmise of chlamydial conjunctivitis. Chlamydia infections were detected in conjunctival smears. Chlamydia trachomatis was confirmed in 20 (15.3%) using ligase chain reaction and C. pneumoniae in 16 (12.3%) children using an indirect immunofluorescent method. Direct captures of chlamydial infections of newborns were included in the study. The authors had also examined 671 newborns in a maternity hospital from January 2002 till May 2003. Conjunctival scraping had been done in 29 (4.3%) cases mainly for mucopurulent conjunctivitis. Chlamydial conjunctivitis was identified only in 4 (0.6%) cases, i.e. C. trachomatis and C. pneumoniae in 2 cases each. Initial clinical symptoms of both types of chlamydial conjunctivitis were similar (mucous discharge with various degrees of eyelid effusion and chemosis mainly on the tarsal conjunctiva). Clinical symptoms of the C. pneumoniae infection were later accompanied by pseudofollicular changes on the tarsal conjunctiva. The complication of this infection was lacrimal obstruction among half of newborns. Clarithromycin in syrup at a dose of 15 mg/kg/per day for 14 days ensured effective treatment of both chlamydial infections. Control scrapings were always negative and simultaneously the pathological conjunctival finding disappeared.

Anti-Bacterial Agents↗
PubMed1995

Positive serology for chlamydia: is it always for Chlamydia trachomatis?

In this study we tried to determine the factual prevalence of Chlamydia trachomatis seropositive women. Sera of 174 sexually active women of reproductive age who attended the emergency room in our gynecology department were tested by both a species-specific solid-phase enzyme immunoassay (SPEIA, ImmunoComb, Orgenics, Israel) and by an immunoperoxidase assay (IPA). One-hundred and twenty-two of 174 women (70.1%) tested were found positive for C. trachomatis by the IPA test. The SPEIA test identified 41 (33.6%) of those as positive for C. trachomatis and 81 (66.4%) positive for C. pneumoniae. We conclude that the currently used IPA method for chlamydia diagnosis overestimates C. trachomatis infection and its specificity for the diagnosis of C. trachomatis is limited. By using the SPEIA test, it is possible to distinguish between C. trachomatis and C. pneumoniae seropositivity.

Antibodies, Bacterial↗
PubMed1992

HLA-DP restricted Chlamydia trachomatis specific synovial fluid T cell clones in Chlamydia induced Reiter's disease.

Synovial fluid (SF) mononuclear cells from a patient with Chlamydia trachomatis induced acute Reiter's disease were directly by limiting dilution in a representative protocol using phytohemagglutinin in the cloning medium. Out of 76 alpha beta-TCR+ CD4+ T lymphocyte clones, 7 were shown to specifically recognize C. trachomatis in a proliferation assay. The antigen recognition of these clones was HLA-DP restricted. Unexpectedly, 2 HLA-DR restricted clones showed a proliferative response to Yersinia enterocolitica O3, though the patient had no history of yersinia infection. The high frequency of SF derived T cells with specificity for species-specific chlamydial antigens and the limited diversity of HLA class II restriction of these clones may indicate an oligoclonal synovial T cell response to persistent intraarticular chlamydia.

Adult↗
PubMed1983

[Non-gonococcal urethritis and cervicitis. Isolation of Chlamydia trachomatis and detection of anti-Chlamydia antibodies by indirect immunofluorescence].

The responsibility of Chlamydia trachomatis in non-gonococcal urethritis and cervicitis was investigated in 267 patients of both sexes. It was confirmed in 36.3% of patients with urethritis and 20.9% of patients with cervicitis by isolating C. trachomatis on Hela 229 cells in the presence of cytochalasin B. No clinical feature specific of C. trachomatis infection could be elicited. The patients were tested for total IgM-type serum anti-chlamydia antibodies by indirect immunofluorescence (IF), using as antigen the inclusions formed in Hela 229 cells by an L2 serotype of C. trachomatis. The serological study was also performed in 86 blood-donors used as controls. The diagnostic value of IF serology is limited in lower genito-urinary infections; the presence of specific IgM's correlates well with the isolation of C. trachomatis, but these IgM's are not detected in protracted urethritis or cervicitis. In such cases, the aetiological diagnosis can only be made by isolation of C. trachomatis from the focus of infection.

Adolescent↗
PubMed1995

[A comparison of Clearview Chlamydia diagnostic tests and direct immunofluorescence (Chlamyset Antigen) in inflammatory gynecological diseases due to Chlamydia trachomatis].

The diagnostic performance of two direct antigen tests is compared, using parallel samples from 90 gynecologic patients. The latter were selected because of clinically suspicious symptoms for chlamydial infection. The incidence of infection in the study group was 33.3%. Compared to direct immunofluorescence Clearview Chlamydia had sensitivity of 80%, specificity of 100%, and the agreement between the two methods was 93.3%. Clearview Chlamydia may serve as a useful diagnostic test in case there is no available laboratory equipment and trained personal.

Adolescent↗
PubMed2000

Evaluation of a commercial test for antibodies to the chlamydial lipopolysaccharide (Medac) for serodiagnosis of acute infections by Chlamydia pneumoniae (TWAR) and Chlamydia psittaci.

A commercial test (rELISA) based on a recombinant chlamydial lipopolysaccharide (LPS) antigen has been evaluated for the diagnosis of acute infections caused by Chlamydia pneumoniae (TWAR) and Chlamydia psittaci. This test and a microimmunofluorescence test (MIF) were compared in 160 patients with community-acquired pneumonia. Seventeen of nineteen cases with significant titre changes detected by rELISA were confirmed by MIF. The two remaining cases not confirmed by MIF were considered false-positive reactions. One case positive by MIF only was judged not to be a true-positive reaction. All three cases occurred in patients with Mycoplasma pneumoniae infection and may be the result of a mitogenic effect. High antibody titres have been used to indicate acute C. pneumoniae infection. We found high MIF or rELISA titres to be equally common in patients and controls; no association between the two tests was detected. An unexpected cross-reactivity between the rELISA antigen and parvovirus was observed, which might have diagnostic implications. Both MIF and rELISA detected acute C. pneumoniae and C. psittaci infection, and there was good agreement between the tests. Single serum diagnosis was generally not feasible with either MIF or rELISA.

Adolescent↗
PubMed1999

In-vitro activity of gatifloxacin against Chlamydia trachomatis and Chlamydia pneumoniae.

We compared the activity of gatifloxacin, a new quinolone, ofloxacin and erythromycin against five isolates of Chlamydia trachomatis and 20 isolates of Chlamydia pneumoniae, including TW183 and clinical isolates from the USA and Japan. Testing was done in cycloheximide-treated HEp-2 cells. Gatifloxacin was slightly less active against C. trachomatis and slightly more active against C. pneumoniae than ofloxacin, with MICs at which 90% of the isolates had no inclusions and minimal chlamydicidal concentrations at which 90% of the isolates had no inclusions after passage of 0.25 mg/L. Gatifloxacin was less active than erythromycin for both species.

Anti-Infective Agents↗
PubMed1979

Host modification of chlamydiae: differential infectivity for cell monolayers of chlamydiae grown in eggs and monolayers.

Cell monolayer-grown chlamydiae (CGO) differed from egg-grown organisms (EGO) in their increased spontaneous infectivity relative to centrifuge-assisted infectivity for monolayers. For each population spontaneous: centrifuge-assisted infectivity ratios were constant over a wide dose range. Spontaneous infection increased linearly with time and could not be exhausted from either population by prolonged adsorption; there was no change in infectivity ratios in residual supernatants. Further, one passage of EGO through monolayers gave CGO with stable infectivity properties not increased by further cell passage yet reverting on a single passage in eggs. Spontaneous infection of monolayers with EGO gave progeny with the same infectivity ratios as monolayers infected with EGO by centrifugation. The change in properties following EGO infection of monolayers occurred prior to natural release from cells. We conclude that EGO and CGO are two phenotypically distinct, homogeneous populations. The two infection modes are not properties of subpopulations within EGO and CGO. The relationship of these observations on chlamydiae to other possible host-imposed phenomena is considered.

Animals↗
PubMed2006

Naturally occurring amino acids differentially influence the development of Chlamydia trachomatis and Chlamydia (Chlamydophila) pneumoniae.

The differential influence of individual amino acids on the growth of Chlamydia trachomatis versus Chlamydia (Chlamydophila) pneumoniae was investigated. Certain essential amino acids added in excess at the middle of the infection course resulted in varying degrees of abnormality in the development of the two species. If amino acids were added as early as 2 h post-infection, these effects were even more pronounced. The most effective amino acids in terms of C. trachomatis growth inhibition were leucine, isoleucine, methionine and phenylalanine. These amino acids elicited similar effects against C. pneumoniae, except methionine, which, surprisingly, showed a lower inhibitory activity. Tryptophan and valine marginally inhibited C. trachomatis growth and, paradoxically, led to a considerable enhancement of C. pneumoniae growth. On the other hand, some non-essential amino acids administered at the middle of or throughout the infection course differentially affected the development of the two species. For example, C. trachomatis growth was efficiently inhibited by glycine and serine, whereas C. pneumoniae was relatively less sensitive to these agents. Another difference was apparent for glutamate, glutamine and aspartate, which stimulated C. pneumoniae growth more than that of C. trachomatis. Overall, several distinctive patterns of susceptibility to excess amino acid levels were revealed for two representative C. trachomatis and C. pneumoniae isolates. Perturbation of amino acid levels, e.g. of leucine and isoleucine, might form a basis for the development of novel treatment or preventive regimens for chlamydial diseases.

Amino Acids↗
PubMed1989

The major outer membrane protein of Chlamydia trachomatis: critical binding site and conformation determine the specificity of antibody binding to viable chlamydiae.

The major outer membrane protein (MOMP) is the prime candidate for the development of a chlamydial vaccine. Antibodies to the subspecies-specific epitope neutralize chlamydial infection. Monoclonal antibodies (MAbs) to this epitope were prepared either by immunization with whole chlamydiae or with a 16 amino acid synthetic peptide. The critical binding site on the subspecies epitope for these MAbs was determined to single amino acid resolution using several hundred solid-phase peptides. A frame shift of just one amino acid in critical binding site completely prevented antibody binding to viable chlamydiae. A single MAb to whole organisms was capable of spanning both the surface-exposed, conformation-dependent, subspecies epitope and a buried, conformation-independent species epitope some 10 A distant. Immunization with peptide generated an MAb with reduced binding constraints which permitted the antibody to bind with broadened species-specificity at the subspecies binding site. The results show for the first time the importance of both critical binding site and conformation at the subspecies epitope. We suggest that the conformational flexibility of short, epitopic peptide vaccines may in some cases be advantageous, giving rise to extended specificity not attained with the natural protein.

Amino Acids↗
PubMed2006

Prior exposure to infection with Chlamydia pneumoniae can influence the T-cell-mediated response to Chlamydia trachomatis.

Using T-cell clones derived from patients with Chlamydia trachomatis (CT)-induced reactive arthritis, we identified target antigens and mapped the peptide epitopes that were recognized. Several epitopes were conserved in homologous proteins of Chlamydia pneumoniae (CPN), and it was shown that these epitopes were generated following processing of the CPN proteins or CPN elementary bodies, i.e. the T-cell clones were indeed CT and CPN cross-reactive. Given that CPN infection is frequent, we wished to determine whether prior infection with CPN could have an effect on the response to subsequent infection with CT. First, we showed that the CPN antigen, OmcB, was recognized by polyclonal peripheral blood T cells from additional subjects with CT-induced reactive arthritis; they were chosen to be HLA-DR-matched with the T-cell clones used to map epitopes in OmcB. Responses to a peptide previously shown to be conserved in CT and CPN OmcB were also seen, but only in CPN-seropositive individuals. These subjects also produced interferon-gamma (IFN-gamma) in response to CPN OmcB, and did not recognize a nonconserved epitope in OmcB. Secondly, OmcB-responsive clones from CPN-seropositive subjects were dominated by those recognizing the cross-reactive epitope, despite the recent exposure of these subjects to CT. Lastly, healthy CPN-seropositive subjects, without evidence of exposure to CT, showed greater responses, measured as IFN-gamma secretion, to CT proteins in vitro than those shown by seronegative subjects. This is consistent with the idea that prior CPN infection primes a Th1 T-cell response to CT antigens. This finding is relevant to the pathogenesis of the sequelae of CT infection (trachoma, infertility and arthritis), which may be influenced by prior exposure to CPN, and to the choice of CT antigens as vaccine candidates.

Arthritis, Reactive↗
PubMed2006

Comparative PCR-based restriction fragment length polymorphism analysis of the plasmid gene orf3 of Chlamydia trachomatis and Chlamydia psittaci.

The BfaI digestion of PCR-based restriction fragment length polymorphism analysis of the plasmid orf3 of Chlamydia trachomatis and Chlamydia psittaci provided evidence for two distinct restriction patterns, respectively. The nucleotide sequences of orf3 genes confirmed these differences. Serum antibodies against recombinant C. psittaci protein (pgp3) encoded by orf3 were detected both in pigeons with C. psittaci infection and in a human patient with psittacosis.

Amino Acid Sequence↗
PubMed1993

In vitro activity of azithromycin (CP-62,993) against Chlamydia trachomatis and Chlamydia pneumoniae.

The in vitro susceptibilities of 49 strains of Chlamydia trachomatis and 3 strains of Chlamydia pneumoniae to azithromycin and tetracycline or doxycycline were determined. The MIC of azithromycin ranged from < or = 0.06 to 1.0 micrograms/ml, the MIC of tetracycline ranged from 0.03 to 0.12 micrograms/ml, and the MIC of doxycycline ranged from 0.015 to 0.06 micrograms/ml against C. trachomatis. The MIC ranges for C. pneumoniae were 0.12 to 0.25 micrograms/ml for azithromycin and 0.06 to 0.12 micrograms/ml for tetracycline. All minimal chlamydicidal concentrations were either equal to the MIC or one or two dilutions higher. No strains resistant to these antibiotics were detected. In vitro activity shows that azithromycin is highly active against C. trachomatis and C. pneumoniae.

Azithromycin↗
PubMed2002

In vitro activities of BMS-284756 against Chlamydia trachomatis and recent clinical isolates of Chlamydia pneumoniae.

The in vitro activities of BMS-284756 (a novel des-fluoroquinolone), levofloxacin, moxifloxacin, and clarithromycin were tested against 5 strains of Chlamydia trachomatis and 20 isolates of Chlamydia pneumoniae. The MIC at which 90% of the isolates were inhibited and the minimal bactericidal concentration at which 90% of the isolates were killed by BMS-284756 for all isolates of C. pneumoniae and C. trachomatis was 0.015 microg/ml (range, 0.015 to 0.03 microg/ml). BMS-284756 was the most active quinolone tested.

Anti-Infective Agents↗
PubMed1986

Molecular characterization of Chlamydia trachomatis and Chlamydia psittaci plasmids.

Plasmids from Chlamydia trachomatis LGV-434 (serotype L2) and Chlamydia psittaci meningopneumonitis strain Cal-10 were cloned into the BamHI and EcoRI sites of pBR322, respectively. The recombinant plasmids pCTL2 and pCPMn, each containing an entire respective chlamydial plasmid, were transformed into Escherichia coli. The sizes of the plasmids of C. trachomatis and C. psittaci were 7.3 and 6.2 kilobases, respectively. The two plasmids were found to be distinct by restriction endonuclease analysis, DNA-DNA hybridization, and electron microscopic heteroduplex analysis. However, partial homology was observed between restriction fragments of pCTL2 and pCPMn by Southern blot analysis. Polypeptide products encoded by these plasmids were synthesized in vitro by an E. coli-directed transcription-translation system and in vivo in E. coli maxicells and minicells. None of these polypeptides was immunoreactive with anti-chlamydial sera by immunoblotting or immunoprecipitation. Based on the comparative analysis data, the C. trachomatis and C. psittaci plasmids were found to share little genetic relatedness.

Chlamydia trachomatis↗