Comparison of polymerase chain reaction and enzyme immunoassay (Chlamydiazyme) in detection of Chlamydia trachomatis from male urethritis]

A method using polymerase chain reaction (PCR) was compared to an enzyme immunoassay (Chlamydiazyme) for detection of Chlamydia trachomatis by testing a reference strain and clinical specimens. Two oligonucleotides based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2 were used as primers for the PCR. A DNA fragment of 242 bp specific for C. trachomatis was amplified by the PCR, when DNA of greater than or equal to 10(2) C. trachomatis was used as template for the PCR. A chlamydial antigen was detected by Chlamydiazyme, when greater than or equal to 2.6 x 10(3) C. trachomatis were applied for the enzyme immunoassay. The PCR method was 26 times more sensitive than Chlamydiazyme in detection of C. trachomatis. The PCR method and Chlamydiazyme were carried out to examine 74 urethral swabs obtained from male patients with urethritis for detection of C. trachomatis. In 45 of 74 specimens, the DNA fragment of C. trachomatis was amplified by the PCR, and in 41 of 74, the chlamydial antigen was detected by Chlamydiazyme. The detection rate of the PCR method (60.8%) was higher than that of Chlamydiazyme (55.4%). The positive coincidence rate of the PCR method to Chlamydiazyme was 100% (41/41) and negative coincidence rate was 87.9% (29/33). The overall coincidence rate between the two methods was high (94.6%). Thus, the PCR method was more sensitive than Chlamydiazyme for detection of C. trachomatis and specific for diagnosis of chlamydial urethritis.     

Detection of Neisseria gonorrhoeae from male patients with urethritis by polymerase chain reaction]

A polymerase chain reaction (PCR) procedure was developed for detection of Neisseria gonorrhoeae. Two oligonucleotides based on sequences within a 16S ribosomal RNA gene from N. gonorrhoeae were used as extension primers for the PCR. A single DNA fragment of 206 bp was amplified, when N. gonorrhoeae DNA was template for the PCR. No amplified product was detected in Chlamydia trachomatis DNA, Ureaplasma urealyticum DNA or other bacterial DNAs. The DNA fragment of 206 bp was detected on agarose gel electrophoresis, when DNA of greater than or equal to 6.5 N. gonorrhoeae per PCR was used as template DNA for the PCR. The culture and the PCR were carried out for detection of N. gonorrhoeae in 67 urethral swabs obtained from male patients with urethritis. In 27 of 28 specimens in which N. gonorrhoeae was isolated and identified by the culture, 206 bp DNA fragment was amplified by the PCR, but in one specimen no DNA fragment was detected. In 2 of 39 culture-negative specimens, 206 pb DNA fragment was detected and in the remaining specimens, PCR was negative for N. gonorrhoeae. The overall detection coincidence rate between the culture and the PCR was 95.5% (64/67). Thus, the PCR procedure developed in this study was sensitive and specific for detection of N. gonorrhoeae and could be applied for diagnosis of gonococcal urethritis.     

Comparison of polymerase chain reaction and IDEIA Chlamydia in detection of Chlamydia trachomatis from first-voided urine of male urethritis patients]

We have reported a method for detection of Chlamydia trachomatis by polymerase chain reaction (PCR) with two oligonucleotides based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2. In the previous report, in addition to treatment of the mixture of first-voided urine (FVU) sediment and 1 ml of urine with proteinase K. DNA purification by phenol extraction was necessary for preparation of template DNA for PCR. In this study, FVU sediment was suspended in 1 ml of Chlamydiazyme dilution buffer and a part of the suspension was treated with proteinase K for DNA extraction. The DNA extraction solution could be used as template for PCR without purification of DNA by phenol extraction. One hundred FVU specimens obtained from male urethritis patients were examined with the two methods (PCR and IDEIA) for detection of C. trachomatis. In 33 of 100 specimens, the DNA fragments of C. trachomatis was amplified by the PCR and in 32 of 100, the chlamydial antigen was detected by IDEIA. The positive and negative coincidence rate of the PCR to IDEIA were 93.8% (30.32) and 95.6% (65/68) respectively, resulting in a high overall coincidence rate at 95%. Thus, the improved method with PCR using FVU as a specimen is proved to be a useful, non-invasive diagnostic tool for diagnosis of chlamydial urethritis.     

Detection of Chlamydia trachomatis from urethral swab in male urethritis by polymerase chain reaction]

A polymerase chain reaction (PCR) with Chlamydia trachomatis-specific primers was applied for detection of C. trachomatis from urethral swab in male urethritis. The results were compared with those of culture method for detection of C. trachomatis. Of 18 clinical specimens tested in this study, inclusion bodies of C. trachomatis were detected in 11 specimens by the culture method. For PCR, sample DNA was prepared from transport medium in which urethral smear was suspended and two oligonucleotides based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2 were used as extension primers. In 12 of the 18 specimens, 242bp DNA fragment was amplified by PCR and demonstrated to be the DNA fragment of C. trachomatis by Southern blot hybridization. No DNA of 242bp was amplified by PCR from five specimens in which any inclusion bodies of C. trachomatis were observed or from a specimen in which one inclusion body per cover slip was detected by culture method. C. trachomatis DNA of 242bp was amplified from all specimens in which 14 and more inclusion bodies per cover slip were detected by culture method. In two specimens concluded s negative by culture method, amplified C. trachomatis DNA were detected by PCR. Thus, the PCR would be a more simple and sensitive method for detection of C. trachomatis, compared with the culture method.     

Detection of Chlamydia trachomatis in first-voided urine sediments from male urethritis by polymerase chain reaction]

Chlamydia trachomatis was detected from first-voided urine sediments of 97 male patients with urethritis by polymerase chain reaction (PCR). Since urine and urinary sediments only treated with proteinase K inhibited DNA amplification by PCR, DNA was further purified by phenol extraction and concentrated. Two oligonucleotides based on sequences within the major outer membrane gene from C. trachomatis serovar L2 were used as primers. A DNA fragment of 242 bp specific for C. trachomatis was amplified by PCR and detected by agarose gel electrophoresis. The DNA fragment was amplified by PCR in all specimens of urine sediments from 50 patients with Chlamydiazyme-positive urethral swab. In 38 specimens of urine sediments from 47 patients with Chlamydiazyme-negative urethral swab, PCR was negative. The overall coincidence rate between the PCR for detecting C. trachomatis in first-voided urine sediments and Clamydiazyme in urethral swab was 90.7% (88/97). Detection of C. trachomatis from first-voided urine sediments by PCR was considered to be noninvasive and useful for the diagnosis of male urethritis due to C. trachomatis.     

Detection of Ureaplasma urealyticum by polymerase chain reaction]

A polymerase chain reaction (PCR) procedure for detection of Ureaplasma urealyticum was developed. A set of oligonucreotides based on sequences within the 16S ribosomal RNA gene from U. urealyticum were used as extension primers for the PCR. A DNA fragment of 397 bp was amplified by the PCR, when U. urealyticum DNA was template for the PCR. No amplified product was detected from other bacterial DNA including those of Mycoplasma genus. The amplified DNA fragment of 397 bp was detected on agarose gel electrophoresis, when DNA of > or = 10(2) cells of U. urealyticum per PCR was used as template for the PCR. Thus, the PCR procedure was shown to be a simple, rapid and specific method for detection of U. urealyticum and could be applied to detection of U. urealyticum from clinical specimens.     

Chlamydial nucleic acids in synovium in osteoarthritis: what are the implications?

OBJECTIVE: To study whether there is evidence of bacterial DNA in some osteoarthritic (OA) joint tissues, and the clinical implications of finding bacterial DNA in this relatively noninflammatory disease. METHODS: Polymerase chain reaction (PCR) was used to detect DNA of Chlamydia trachomatis, Chlamydia pneumoniae, and other bacteria using panbacterial primers in synovial membranes and other articular tissues of 32 consecutive patients undergoing surgery for hip and knee OA. Patients were interviewed and examined postoperatively. Operative reports were reviewed and followup examinations were accomplished on all patients. RESULTS: Nine of 32 patients with OA (28.1%) had evidence for bacterial DNA in joint tissues with at least one set of primers for Chlamydia: 7 for C. trachomatis (21.9%), 2 for C. pneumoniae (6.2%). Five of 32 (15.6%) patients had postoperative complications; 3 of these were in patients who showed amplified DNA of C. trachomatis in joints and one in a patient in whom we detected Escherichia coli. CONCLUSION: C. trachomatis and C. pneumoniae nucleic acids can be present in joints in some cases of apparently classical OA. Whether chlamydial or other difficult to culture bacterial presence is associated with complications is suggested, but remains to be determined. Simple presence of C. trachomatis by PCR does not define a clinical syndrome or disease course.     

Optimised sample DNA preparation for detection of Chlamydia trachomatis in synovial tissue by polymerase chain reaction and ligase chain reaction

OBJECTIVE: Molecular biology techniques such as polymerase chain reaction (PCR) and ligase chain reaction (LCR) are routinely used in research for detection of C trachomatis DNA in synovial samples, and these methods are now in use in some clinical laboratories. This study aimed at determining the method best suited to molecular diagnosis of C trachomatis by examining four standard DNA preparation methods using chlamydia spiked synovial tissue and chlamydia infected monocytes. METHODS: Synovial tissue from a chlamydia negative patient with rheumatoid arthritis was spiked with defined numbers of C trachomatis elementary bodies (EB). Purified human peripheral monocytes from normal donors were infected with the organism at a multiplicity of infection 1:1 in vitro and harvested after four days. DNA was prepared from all samples by four methods: (1) QIAmp tissue kit; (2) homogenisation in 65 degrees C phenol; (3) incubation at 97 degrees C; (4) proteinase K digestion at 97 degrees C. DNA from methods 1 and 2 was subjected to PCR using two different primer sets, each targeting the C trachomatis omp1 gene. LCR was done on DNA prepared by each method. RESULTS: In synovial tissue samples spiked with EB, and in monocytes persistently infected with the organism, preparation of template using the QIAmp tissue kit (method 1) and the hot phenol extraction technique (method 2) allowed sensitive detection of C trachomatis DNA. These methods also produced template from both sample types for LCR. DNA prepared by heat denaturation (method 3) allowed only low sensitivity chlamydia detection in LCR and did not work at all for PCR. Proteinase K digestion plus heat denaturation (method 4) gave template that did not allow amplification in either PCR or LCR assays. CONCLUSIONS: The sensitivity of detection for C trachomatis DNA in synovial tissue by PCR and LCR depends strongly on the method used for preparation of the amplification template. LCR targeting the multicopy chlamydial plasmid and two nested PCR assay systems targeting the single copy omp1 gene showed roughly equivalent sensitivity. Importantly, template preparation method and the specific PCR primer system used for screening must be optimised in relation to one another for highest sensitivity.     

Detection and differentiation of Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae by DNA amplification

The polymerase chain reaction was used to detect major outer membrane protein (MOMP) gene sequences from the three species of Chlamydia. Using three primer pairs and one restriction enzyme digestion, three distinct genotypes, corresponding to the three species, Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci, were demonstrated. C. trachomatis was amplified by all three primer pairs and the amplified fragment was digested by EcoRI. C. pneumoniae was amplified by only two of the three primer pairs, and the amplified fragment was digested by EcoRI. C. psittaci was amplified by only two of the pairs and the amplified fragment was EcoRI-resistant. C. trachomatis was detected in direct patient specimens, tissue culture specimens, and fixed specimens, and all serovars of C. trachomatis were detectable. The polymerase chain reaction can detect and differentiate the three species of Chlamydia and may prove a valuable diagnostic tool.     

Typing Chlamydia trachomatis by detection of restriction fragment length polymorphism in the gene encoding the major outer membrane protein.

A method that avoids culture was devised to determine serovars of Chlamydia trachomatis. Polymerase chain reaction was used first to amplify a part of the chlamydial genome that included the leader sequence and all four variable domains of the major outer membrane protein (MOMP) of the 15 serovars of C. trachomatis. The amplified DNA was then digested simultaneously with restriction endonucleases AluI and MspI and the resulting fragments separated on 10% polyacrylamide gels. After silver staining, a total of 13 characteristic patterns were observed for the 15 serovars, leaving two ambiguities that were resolved using alternate enzymes. Analysis of 40 clinical isolates revealed patterns indistinguishable from those of the prototype serovars including, unexpectedly, 5 Ba serovars. The same PCR procedure also allowed amplification of the MOMP gene of two avian Chlamydia psittaci and one Chlamydia pneumoniae isolates.     

General colorimetric method for DNA diagnostics allowing direct solid-phase genomic sequencing of the positive samples.

A system for rapid colorimetric detection of specific genome DNA fragments amplified by the polymerase chain reaction (PCR) is described that has been designed to allow direct solid-phase sequencing of positive samples. The amplified material is immobilized on magnetic beads by using the biotin streptavidin system. An Escherichia coli lac operator DNA sequence is incorporated in the amplified material during the second step of a nested primer procedure. This 21-base-pair sequence is used for a general colorimetric detection with a fusion protein consisting of the E. coli Lac repressor and beta-galactosidase. Positive samples can be treated subsequently with alkali to obtain a single-stranded DNA template suitable for direct genomic sequencing. This method to detect immobilized amplified nucleic acids (DIANA) is well adapted for automated or semiautomated clinical assays. Here, we show that it can be used to detect and sequence Chlamydia trachomatis genomic DNA in clinical samples.     

Evaluation of amplicor chlamydia PCR and LCX chlamydia LCR to detect Chlamydia trachomatis in synovial fluid

OBJECTIVES: PCR has been successfully used in research for the detection of C. trachomatis DNA in synovial samples. However, each research laboratory has developed its own PCR, making inter-laboratory comparisons difficult. To allow for standardization we evaluated two commercially available amplification systems originally designed for the examination of urogenital samples (Roche Amplicor Chlamydia PCR and Abbott LCX Chlamydia LCR), using them to analyse spiked and clinical synovial fluid (SF) samples from reactive arthritis (ReA), undifferentiated arthritis (UA), and rheumatoid arthritis (RA) patients. We compared their sensitivity in assays of clinical SF samples with our in-house developed C. trachomatis specific nested PCR. METHODS: SF was spiked with purified C. trachomatis elementary bodies (EB) and analyzed by the commercial assays. Clinical SF samplesfrom ReA (n=21), UA (n=79) and RA (n=50) patients were examined by the two commercial assays and our in-house PCR. RESULTS: Using SF samples spiked with defined numbers of C. trachomatis EB, the sensitivity of the commercial tests was high and similar to published PCR sensitivity. In clinical SF specimens the commercial assays was also able to detect CT; however, the in-house PCR was more sensitive. Out of 10 PCR-positive SF samples Amplicor tested positive in only 4/10 and LCX in only 3/10. The in-house PCR detected chlamydial DNA in synovialfluidfrom 5/21 ReA (24%), 5/79 UA (6%) and in none of the 50 RA patients. CONCLUSION: Commercial amplification assays allow the detection of C. trachomatis in clinical specimens, although with a lower sensitivity than optimized PCR. Potential explanations are discussed.     

<Emphasis Type="Italic">Chlamydia trachomatis</Emphasis>-Specific Heat Shock Proteins 60 Antibodies can Serve as Prognostic Marker in Secondary Infertile Women

BACKGROUND: : The magnitude of reproductive morbidity associated with sexually transmitted Chlamydia trachomatis infection is enormous. A predictive serological test for upper genital tract infection would be a desirable diagnostic tool as C. trachomatis infection may lead to various immunopathological sequelae such as infertility, or ectopic pregnancy. MATERIALS AND METHODS: : Female patients (n = 198) attending gynecology outpatient department of Safdarjung hospital were enrolled for the study and clinically characterized into four groups on the basis of their symptoms; discharge, chronic cervicitis, primary and secondary infertility. Serological detection of C. trachomatis was done by ELISA using specific peptide sequences of major outer membrane protein (MOMP), Chlamydia heat shock protein (cHSP60 and 10). RESULTS: : Significant high seropositivity to chlamydial anticHSP60 antibodies were detected in patients with secondary infertility. A significant percent of chlamydial reinfection was observed in patients having secondary infertility (82.6%; p < 0.01) and chronic cervicitis (64.28%; p < 0.05). Considering IgG MOMP ELISA as a test standard, anti-cHSP60 antibodies showed higher sensitivity (90.91%) and specificity (89.47%) than cHSP10 ELISA (75.6% and 73.87%) in the secondary infertile group. Further anticHSP60 antibodies' detection had a sensitivity of 67.33% and a specificity of 90.67% in secondary infertile women when compared with DFA and PCR. CONCLUSIONS: : Our data suggest that detection of anticHSP60 antibodies would help in early prognosis of immunopathological sequelae in C. trachomatis-infected women and thereby in instituting appropriate therapy for controlling C. trachomatis infection at an early stage.     

鹦鹉热衣原体套式PCR和DNA测序方法研究

目的　建立特异、灵敏、快速的鹦鹉热衣原体 (Cps)分子生物学检测方法。 方法　采用套式PCR扩增检测和DNA测序方法 ,并进行实验室评价。结果　 4株Cps均能被套式PCR扩增出 2 14bp目的条带 ,而沙眼衣原体、肺炎衣原体、肺炎支原体等其它微生物均不能检出 ;Cps套式PCR灵敏度高于CpsPCR ;模拟样本均能被检出。Cps(CS株 )套式PCR产物直接测序与Cps典型株序列完全一致。结论　套式PCR是检测Cps特异、灵敏 ,且快速的分子生物学检测方法     

Chlamydia pneumoniae in abdominal aortic aneurysms: abundance of membrane components in the absence of heat shock protein 60 and DNA

In this article, we describe the results of a comparative study for the detection of Chlamydia pneumoniae in abdominal aortic aneurysm specimens of 19 patients through the use of immunocytochemistry (ICC), in situ hybridization (ISH), and polymerase chain reaction (PCR), along with the detection of cytomegalovirus (CMV) and herpes simplex virus (HSV) by ICC and PCR. C pneumoniae-specific membrane protein was detected in specimens of all 19 (100%; 95% confidence interval [CI] 82% to 100%) and of 15 (79%; 95% CI 54% to 94%) patients with monoclonal antibodies RR-402 and TT-401, respectively. Chlamydial lipopolysaccharide was detected in specimens of 15 (79%; 95% CI 54% to 94%) patients when the results of 4 different monoclonal antibodies were combined. Surprisingly, chlamydial heat shock protein 60 was not detected in any of the specimens by ICC. Furthermore, C pneumoniae DNA was not detected by ISH when a C pneumoniae major outer membrane protein gene fragment was used as probe, nor was it reproducibly detected by PCR on extracted DNA. These results may be explained either by different kinetics of degradation of the different components of C pneumoniae after infection of the vessel wall or by the involvement of other Chlamydia-like microorganisms. Coexistence of C pneumoniae antigens and HSV antigens but not CMV antigens was observed in specimens from 10 of 18 (56%; 95% CI 31% to 78%) patients by ICC. CMV and HSV DNAs were not detected by PCR. In conclusion, we have demonstrated the presence of antigens of C pneumoniae in the absence of specific DNA in abdominal aortic aneurysms, suggesting persistence of the antigens rather than a persistent infection.     

Detection of Neisseria gonorrhoeae in first-voided urine sediments from male urethritis patients by polymerase chain reaction]

Neisseria gonorrhoeae was detected from first-voided urine sediments of male patients with urethritis by polymerase chain reaction (PCR). Urine and urinary sediment were treated with proteinase K, and DNA was further purified by phenol extraction. Two oligonucleotides based on sequences within a ribosomal RNA gene from N. gonorrhoeae were used as primers for the PCR. A DNA fragment of 206 bp specific for N. gonorrhoeae was amplified by PCR and detected by agarose gel electrophoresis. In 19 specimens of urine sediments collected from 21 patients in whom N. gonorrhoeae was isolated from urethral swab by culture, 206 bp DNA fragment was amplified by PCR. In all specimens of urine sediments from 24 patients in whom cultures for N. gonorrhoeae were negative, no DNA was amplified by the PCR. The overall coincidence rate between the PCR for detecting N. gonorrhoeae in first-voided urine sediments and culture in urethral swab was 95.6% (43/45). PCR procedure for detection of pathogens from first-voided urine sediments would be noninvasive and would be applied for the diagnosis of gonococcal urethritis and chlamydial urethritis.     

Reactivity of a dual amplified chlamydia immunoassay with different serovars of Chlamydia trachomatis.

A study was undertaken with different serovars (D, E, F, L2, MoPn) of Chlamydia trachomatis to determine the analytical sensitivity of a new dual amplified immunoassay (IDEIA PCE Chlamydia) for detecting chlamydial lipopolysaccharide. IDEIA PCE Chlamydia incorporates a polymer conjugate consisting of multiple copies of antibody and enzyme molecules to provide signal amplification. The test was also assessed with different protein A producing strains of Staphylococcus aureus in order to assess whether the use of a multiple antibody conjugate increased nonspecific binding. The detection limits varied for each serovar with a detection limit of 38 IFU/ml obtained with serovar F and 237 IFU/ml obtained with serovar D. The incorporation of the polymer conjugate resulted in a 2-5 fold increase in analytical sensitivity compared to an earlier version of the test using a conventional conjugate. No increase in cross reactivity with protein A producing strains of S. aureus was obtained. The new dual amplified test format offers potential as a sensitive low-cost screening assay for C. trachomatis infections.     

Deoxyribonucleic acid amplification and hybridisation in Crohn''s disease using a chlamydial plasmid probe.

The possibility that Crohn's disease is caused by infection with Chlamydia trachomatis was examined by probing for chlamydial plasmid deoxyribonucleic acid (DNA) in DNA extracts from Crohn's disease tissue and by means of a serological study. Gut DNA extracts were obtained from 10 patients with Crohn's disease and four control subjects and were probed with a chlamydial plasmid probe after Southern blotting. The polymerase chain reaction was also used to amplify any chlamydial plasmid DNA present in tissue DNA extracts, before Southern blotting and probing. Chlamydial proctitis control specimens were not available: gut DNA extracts mixed with traces of chlamydia plasmid served as positive controls. Using these techniques, no chlamydial plasmid DNA sequences were found in Crohn's disease tissue. An enzyme linked immunosorbent assay for C trachomatis LI was performed on 48 patients with Crohn's disease and 48 control subjects. Seropositivity was present in 14.6% of patients and 29% of control subjects and was not statistically significant (p greater than 0.05). The failure to show chlamydial DNA and the lack of serological response to chlamydia make C trachomatis infection a very unlikely factor in the pathogenesis of Crohn's disease.     

Ligase chain reaction in detection of Chlamydia DNA in synovial fluid cells

Synovial fluid cells from 12 patients with reactive arthritis (ReA) triggered by Chlamydia trachomatis were studied for the presence of Chlamydia DNA using the ligase chain reaction (LCR) LCx (Abbott) and the polymerase chain reaction (PCR) Amplicor (Roche). In addition, peripheral blood leucocytes from 11 of these patients were analysed by LCR. As controls, seven patients with newly diagnosed rheumatoid arthritis (RA) were included. Chlamydia trachomatis DNA was detectable by LCR in samples of synovial fluid cells from 4/12 patients with C. trachomatis-triggered ReA, and in none by PCR. Chlamydia trachomatis DNA was not detectable in the synovial fluid cells of the seven RA patients by either method, neither was C. trachomatis DNA detectable in the peripheral blood leucocytes of the ReA patients (0/11) or controls (0/6) by LCR. The LCR technique may be useful in the demonstration of Chlamydia DNA in synovial fluid cells.