Chlamydia pneumoniae DNA in peripheral venous blood samples from patients with carotid artery stenosis.

In the study presented here, peripheral blood specimens obtained from patients with atherosclerosis were examined for the presence of Chlamydia pneumoniae to determine whether these specimens can be used for routine testing. Chlamydia pneumoniae DNA was detected in 7 of 56 patients with carotid stenosis and in three of four patients with other atherosclerotic diseases, but it was not detected in any of 50 healthy controls or in any of 59 age- and gender-matched patients suffering from other nonatherosclerotic diseases. IgG antibodies indicative of an active Chlamydia pneumoniae infection were detected by microimmunofluorescence in two of nine PCR-positive patients but in none of 41 PCR-negative patients. Four of nine serum samples obtained from PCR-positive patients contained IgA antibodies compared to 5 of 41 samples obtained from PCR-negative patients.

Detection of seroconversion and persistence of Chlamydia trachomatis antibodies in five different serological tests.

Microimmunofluorescence (MIF), a Chlamydia trachomatis species-specific enzyme immunoassay incorporating lipopolysaccharide-extracted Chlamydia trachomatis L2 elementary bodies, two different synthetic peptide-based species-specific tests, and a recombinant lipopolysaccharide genus-specific test were performed on multiple follow-up sera (n = 104 total) from 16 women with Chlamydia trachomatis-positive cervical swabs. These women included five with IgG seroconversions, five with Chlamydia trachomatis reinfections after initial therapy, and six with serologic follow-up of more than 6 years after antibiotic therapy. Of all the tests employed in this study, MIF IgG reverted earliest to negative titers, while MIF IgA was the least sensitive. The lipopolysaccharide-extracted elementary body enzyme immunoassay exhibited the closest correlation with the MIF test. The highest test sensitivity was observed in one of the synthetic peptide-based tests, which detected earliest seroconversions and longest IgG persistence. The other synthetic peptide-based test gave false-negative results in 2 of 16 women and did not detect seroconversion earlier than the MIF test. Seroconversion and persistence of genus-specific IgG--cross-reactivity with Chlamydia pneumoniae--against lipopolysaccharide were similar to species-specific IgG. A significant serologic response to reinfection was observed only in women with signs of pelvic inflammatory disease. Species-specific tests of high sensitivity and reproducibility are best suited for gynecological diagnostic purposes.

In vitro susceptibilities of Chlamydia pneumoniae isolates from German patients and synergistic activity of antibiotic combinations.

The susceptibilities of six Chlamydia pneumoniae type strains and of six German patient isolates to erythromycin, azithromycin, roxithromycin, clarithromycin, doxycycline, ofloxacin, and rifampin were investigated. MICs and minimal chlamydicidal concentrations were all within the ranges reported previously. Combinations of azithromycin with either ofloxacin, doxycycline, or rifampin, as well as combinations of three antibiotics (rifampin, azithromycin, and ofloxacin or doxycycline), showed synergistic activity against C. pneumoniae.

[Chlamydia pneumoniae infection in a family]. / Chlamydia-pneumoniae-Infektion in einer Familie.

UNLABELLED: HISTORY AND SYMPTOMS: For 11 weeks a 38-year-old woman had suffered from a respiratory infection with peribronchitis, nocturnal coughing fits and earache. INVESTIGATIONS, TREATMENT AND COURSE: The Chlamydia-CFR titre was raised. Subsequent throat swabs of her husband and two daughters grew Chlamydia pneumoniae (C.p.), but not in her case; 5 days earlier she had been started on roxithromycin. 3 weeks before the patient fell ill her two daughters had a flu-like illness with cough and subfebrile temperature and her husband also had flu-like symptoms, which regressed after few days. Antibiotic treatment with roxithromycin improved the symptoms in the mother and older daughter, but the younger daughter was not given treatment because she had no symptoms at the time the microorganism had been isolated. She developed joint symptoms, like those of reactive arthritis, 12 weeks after the mother's illness had begun, and conjunctivitis 5 weeks later. CONCLUSIONS: It is likely that the daughters had the C.p. infection first and then infected their parents. While the father's and older daughter's illness quickly regressed, the mother became quite ill. Her serology was positive for a primary infection in adulthood, but in the daughters the serology was negative and, despite demonstration of the organism, the diagnosis of acute C.p. infection could not be made.

Evaluation of a new commercial microimmunofluorescence test for detection of antibodies to Chlamydia pneumoniae, Chlamydia trachomatis, and Chlamydia psittaci.

A new commercial test for chlamydial serology, the MRL-Micro-Immunofluorescent Test (MRL; MRL Diagnostics, USA) was compared with the standard microimmunofluorescence test (MIF) using sera from 246 patients. Chlamydia pneumoniae immunoglobulin G (IgG) antibodies were detected in 46.3% (MIF) and 64.2% (MRL) of sera and Chlamydia trachomatis IgG in 23.2% (MIF) and 25.2% (MRL); Chlamydia psittaci IgG antibodies were found with the MRL in 1% of the sera from a general population and in 17.3% of preselected sera with elevated complement fixation titers. Titers were usually higher with the MRL. IgG titers of > or = 1:512 were detected in only 2% of sera using the standard MIF but in 30% using the MRL. In 16 sera from three Chlamydia pneumoniae culture-positive patients, the diagnosis of acute infection could be confirmed serologically in one with the MRL test but in none with the MIF test, indicating a higher sensitivity of the MRL.

Reactions of polyclonal and neutralizing anti-p54 monoclonal antibodies with an isolated, species-specific 54-kilodalton protein of Chlamydia pneumoniae.

A recently described 54-kDa protein has been detected in six type strains and three patient isolates of Chlamydia pneumoniae by immunoblotting with sera from patients positive for antibodies to C. pneumoniae by the microimmunofluorescence test. This protein was not found in either C. trachomatis E or C. psittaci Z 432 as an antigen, confirming its species specificity. The 54-kDa protein was isolated by continuous-elution electrophoresis and immunoglobulin G monoclonal antibodies (MAbs) against the isolated antigen were produced. MAb 8B11E6 reacted only with the 54-kDa band of C. pneumoniae and not with C. trachomatis E or C. psittaci in a Western immunoblot assay. This antibody was purified and tested for neutralizing activity together with three additional anti-p54-active MAbs (8B11E6, 8B11B4, and 10F1C1). In Buffalo green monkey cells, all of the MAbs significantly reduced the infectivity of C. pneumoniae elementary bodies, whereas no neutralizing activity could be observed with C. trachomatis E or C. psittaci Z 432. These results not only confirm the species specificity of the 54-kDa protein but also indicate that this protein might play an important role in the pathogenesis of C. pneumoniae infection. Furthermore, the results suggest a possible protective role of anti-p54 antibodies in an adaptive immune response.

Evidence of labile inhibitors in the detection of Chlamydia trachomatis in cervical specimens by polymerase chain reaction.

A total of 276 cervical swabs (241 from first visits and 35 from follow-up visits) from 241 women were tested for Chlamydia trachomatis by polymerase chain reaction (PCR) and enzyme immunoassay (EIA). Sixty-one smears (53 from first visits and 8 from follow-up visits) from 53 women were stained by direct fluorescent antibody (DFA). Twenty-one (8.7%) women had positive swabs in at least two different tests. All follow-up swabs (collected between 3 days and 3 weeks after the first clinical visit) were positive in at least one test when the woman had been positive at the first visit and no antibiotic treatment had been initiated. Including swabs from follow-up visits and DFA results, the respective sensitivities and specificities of the assays were as follows: PCR, 75.9% and 100%; EIA, 69% and 98.4%. The seven swabs that were false negative by PCR (tested initially after thawing from -20 degrees C) were mailed nonrefrigerated to the assay manufacturer, where they tested true positive. These data point to labile inhibitors of the PCR, predominantly cervical mucus.

Immune response to Chlamydia trachomatis heat-shock protein in infertile female patients and influence of Chlamydia pneumoniae antibodies.

A total of 446 sera from 245 patients with primary or secondary infertility, all of whom were examined laparoscopically, 117 patients with Chlamydia trachomatis-positive cervical swabs, and 84 control persons (50 obstetric patients and 34 female blood donors) were tested for antibodies to Chlamydia trachomatis and to Chlamydia pneumoniae with the microimmunofluorescence (MIF) test. MIF test antibody rates were highest in patients with complete tubal occlusion (73%) and in patients with proven Chlamydia trachomatis infection (74%), whereas only 9 to 10% of the control group showed Chlamydia trachomatis antibodies. Reaction to the 60 kDa antigen of Chlamydia trachomatis, a heat-shock protein (hsp) analogue, has been suggested as a possible marker for the development of chronic sequelae after Chlamydia trachomatis infection. Immunoblot analysis of 222 sera (169 infertility patients, 20 antigen-positive patients, and 33 mothers) showed a significantly higher anti-hsp antibody rate in patients with complete tubal occlusion than in infertility patients with normal fallopian tubes (76% vs. 19%, p < 0.001). The presence of antibodies not only to Chlamydia trachomatis but also to Chlamydia pneumoniae in the MIF test was associated with a significantly higher rate of anti-hsp antibodies and with complete tubal occlusion. This association did not appear to be due to cross-reactivity between Chlamydia pneumoniae and Chlamydia trachomatis antibodies in the MIF test.

Identification of Chlamydia pneumoniae-specific protein antigens in immunoblots.

The immunoblot patterns of 248 sera, all examined previously by the microimmunofluorescence test (MIF) for species-specific Chlamydia antibodies, were analyzed. Predominant specific antibody activity was directed to the 54 kDa protein of Chlamydia pneumoniae, which was recognized by 93% of sera positive for Chlamydia pneumoniae by MIF but by only 2% of sera positive for Chlamydia trachomatis and negative for Chlamydia pneumoniae and by 3% of sera negative for both Chlamydia pneumoniae and Chlamydia trachomatis. This antigen appears to be specific for Chlamydia pneumoniae. Other Chlamydia pneumoniae-specific protein antigens were recognized far less frequently. Absorption analysis indicated that the 54 kDa protein is located on the surface of the Chlamydia pneumoniae elementary bodies.

Comparison of serological tests for the detection of antibodies against Chlamydia trachomatis and Chlamydia pneumoniae in rheumatological patients.

In cases of reactive arthritis, a suspected Chlamydia trachomatis infection is often detected by serological methods. However, mostly tests with genus-specific antigens are used, neglecting the fact that antibodies against Chlamydia pneumoniae are highly prevalent in the adult population. Therefore we tested sera of 129 patients with various rheumatological disorders and of 18 healthy persons in parallel with a genus-specific test (IPAZYME) and with the species-specific microimmunofluorescence test for C. trachomatis and C. pneumoniae antibodies. The data showed that 55% of the 64 IPA-positive results were caused by antibodies (IgG) against Chlamydia pneumoniae, only 6% by anti-Chlamydia trachomatis IgG and 20% by both specificities. For IgA antibodies, the percentages were 44%, 12.5% and 12.5% respectively. In 12 IPA-positive cases, the MIF showed no reaction. 58% of all 147 sera tested with MIF had IgG antibodies against C. pneumoniae, 5% had anti-C. trachomatis IgG and 8% IgG against both species. The percentages for IgA were 29%, 2% and 2%, respectively. IgM positivity in MIF disappeared after absorption with rheumatoid factor absorbent. No significant differences were found between the various groups of patients. The data suggest that due to the high prevalence of anti-C. pneumoniae antibody, genus-species tests cannot be used as screening tests for the serological diagnosis of C. trachomatis infections.

Prevalence of antibodies to Chlamydia pneumoniae TWAR in a group of German medical students.

Prevalence of antibodies to Chlamydia pneumoniae TWAR in Germany has not been previously evaluated. Therefore a healthy adult population of 353 German medical students (mean age 24 years) was examined with a species-specific microimmunofluorescence test for IgG, IgM and IgA antibodies to C. pneumoniae and in parallel to Chlamydia trachomatis. Altogether, 229 persons had IgG antibodies to C. pneumoniae (64.9%), 136 had IgA antibodies (38.5%), while the serum of only one contained specific IgM. Prevalence rates were higher in males (69.4%) than in females (57.3%). The total prevalence for antibodies to C. trachomatis was 5.9%. The results indicate that C. pneumoniae infections are highly endemic in Germany, and that primary infection probably takes place in children or young adults. Prevalence of antibodies to C. pneumoniae in this group of healthy young adults was about 10-fold higher than that to C. trachomatis. This finding needs to be taken into account when genus-specific tests are used for studying Chlamydial antibodies.