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The antibody response to heat shock proteins 60 and 10 were studied in 163 patients with tubal factor infertility and in 163 age-matched pregnant women. The associations of these antibodies with specific antibodies to Chlamydia trachomatis and to Chlamydia pneumoniae as well as with antibodies to the common chlamydial lipopolysaccharide antigen were studied. Patients with tubal factor infertility had significantly higher frequencies and titres of all antibodies except to C. pneumoniae. In a logistic regression model an association was found between the prevalence of antibodies to the heat shock proteins and to C. trachomatis but no independent influence of antibodies to C. pneumoniae. No interaction between C. trachomatis and C. pneumoniae suggesting a synergistic effect was found although the heat shock proteins from these two organisms are immunologically similar. Antibodies to the chlamydial lipopolysaccharide also seemed to be related to C. trachomatis and not to C. pneumoniae in these women.

A Chlamydia trachomatis variant that contains a 377 bp deletion in the cryptic plasmid was recently reported in Sweden. This deletion includes the targets for Cobas Amplicor, Cobas TaqMan48, and Abbott m2000. We examined the proportion and characteristics of this variant in Orebro county, Sweden and developed an effective diagnostic solution. In total, 2,401 consecutive C. trachomatis culture samples and 536 PCR samples from symptomatic and asymptomatic patients and screened females were included. Culture, Cobas Amplicor, and LightMix 480HT were used for diagnosis. A mutant-specific PCR, plasmid sequencing, omp1 sequencing and multilocus sequence typing (MLST) were used to identify and characterise mutants. In total, 162 (6.7%) of the cultured samples were positive for C. trachomatis. However, 61 (38%) of those were negative when using Cobas Amplicor, and 60 of these were subsequently confirmed as the new variant. 13 of these mutant isolates were further characterised genetically, and all were of identical genotype E and the unique MLST sequence type: 21, 19, 1, 2, 1. Of all culture-positive samples, 161 of 162 were positive in the LightMix 480HT assay. The single negative sample was only weakly positive in culture, and negative in all PCRs. Of the 536 PCR samples, 37 were positive in both Cobas Amplicor and LightMix 480HT, 13 were only positive in LightMix 480HT (mutants), and two were only positive in Cobas Amplicor. Mutated C. trachomatis were prevalent in Orebro county in the period from October 2006 to February 2007, and it appeared to be a single clone. LightMix 480HT seemed sensitive, specific, and enabled high throughput diagnostics. However, rare low positive samples may be false-negative. Frequent surveillance and evaluations of diagnostic methods worldwide are crucial.

Nested polymerase chain reaction (nPCR) demonstrated the presence of Chlamydia pneumoniae-specific DNA in peripheral blood mononuclear cells (PBMC). PBMC samples were obtained from 103 consecutive patients (62 male, 41 female) aged 22-85 years (mean, 64) admitted for coronary angiography because of suspected coronary heart disease and from 52 blood donors (43 male, 9 female) aged 40-64 years (mean, 49). Of the 101 evaluable patients, 60 (59%) were identified by nPCR assay as C. pneumoniae DNA carriers; C. pneumoniae-specific microimmunofluorescence (MIF) serology confirmed exposure to the bacterium in 57 (95%) of the 60 nPCR-positive patients. Among the 52 blood donors, the nPCR assay identified 24 (46%) C. pneumoniae DNA carriers, all of whom were positive by C. pneumoniae-specific serology. Thirty-two patients (32%) and 23 blood donors (44%) were MIF antibody-positive but repeatedly nPCR-negative; Bartonella henselae- or Bartonella quintana-specific antibodies were not detected among any of these subjects. In this study, C. pneumoniae DNA was common in PBMC of patients with coronary heart disease and in middle-aged blood donors.

Background Genital chlamydia infections often are asymptomatic, which promotes their spread in the population. In women, the possible consequences of infection are pelvic inflammatory disease and infertility. Most studies on the prevalence of Chlamydia trachomatis have been based on clinical series, and prevalences tend to vary with the clinical setting. Few seroepidemiologic studies have emerged from industrialized countries. Goal of this Study To assess the prevalence of Chlamydia trachomatis using culture and serology, and its relationship with possible risk factors. Study Design This was a population-based study involving completion of a self-administered questionnaire, analysis of cervical samples for Chlamydia trachomatis, and serologic tests for Chlamydia trachomatis antibodies. Results The prevalence of Chlamydia trachomatis infection was 2.7 %, and the seroprevalence was 24.7 % among the sexually active women. Seropositivity was correlated with sexual behavior variables, and the incidence of serologic cross-reactivity with respiratory infections (strain TWAR) was low. Multivariate logistic regression analysis showed the number of sexual partners, age at first coitus, history of therapeutic abortion, and previous pelvic inflammatory disease to be independently correlated with seropositivity. Conclusion Early sexual experience and multiple lifetime sexual partners are independent risk factors for Chlamydia trachomatis infection.

Background: Serology is often used for the diagnosis of Mycoplasma pneumoniae. It is important to identify specific antigens that can distinguish between the presence or absence of antibodies against M. pneumoniae. The two proteins, P116 and P1, are found to be immunogenic. By using these in ELISA it is possible to identify an immune response against M. pneumoniae in serum samples. Results: A recombinant protein derived from the P116 protein and one from the P1 protein were used in two ELISA tests, rP116-ELISA and rP1-ELISA. Human serum samples from patients with atypical pneumonia were tested and compared to the results of the complement fixation test. There was a good agreement between the two tests but the rP1-ELISA showed the best discrimination between positive and negative samples. Conclusion: Two ELISA tests based on recombinant proteins have been analysed and compared to the complement fixation test results. The two ELISA tests were found suitable for use in serodiagnostics of M. pneumoniae infections. The use of specific antigens eliminates the risk of cross reaction to an immune response against other bacteria.

Serum antibodies to Chlamydia trachomatis were studied by microimmunofluorescence (micro-IF) testing and by immunoblotting among 52 women with C. trachomatis cervical infection. All women underwent therapeutic abortion, and 10 (19.2%) subsequently developed laparoscopically confirmed salpingitis. Women who developed salpingitis had lower geometric mean titers of micro-IF antibody before abortion (14.9 x/divided by 2.3) than did women who did not develop salpingitis (41.6 x/divided by 4.9, P less than .01). Women who developed salpingitis significantly less often had serum IgA antibodies to a 60-kilodalton (kDa) chlamydial antigen (P = .02) and IgG antibodies to antigens of 75-kDa (P = .008), 60-kDa (P = .03), and 57-kDa (P = .0003). Serum antibodies to 100-kDa, 32-kDa, and 29-kDa antigens occurred only in women who did not develop salpingitis. Differences in antibody prevalence to specific chlamydial antigens were not due to differences in serum antibody titers between the two groups. No correlation between neutralizing sera and the risk of postabortal salpingitis was detected.

Background: The etiology and significance of flu-like symptoms often appearing before myocardial infarction should be clarified. Methods: In a case-control study of 323 matched controls and a random sample of 110 out of 351 cases the presence of infection symptoms during the preceding four weeks before admission were asked and blood samples taken. Results: Enterovirus (EV), herpes simplex virus (HSV), and Chlamydia pneumoniae IgA titers were significantly higher in cases than in controls ( p Conclusions: Odds ratios for a coronary event in a logistic regression model were 4.79 for fatigue and 2.72 for EV antibody levels in their fourth quartile. A linear-by-linear association test showed increasing number of single symptoms with higher EV titer quartiles ( p = 0.004).

The humoral immune response to Chlamydia outer membrane protein 2 (Omp2) was studied. Omp2 is a highly genus-conserved structural protein of all Chlamydia species, containing a variable N-terminal fragment. To analyze where the immunogenic parts were localized, seven highly purified truncated fusion proteins constituting different regions of the protein were produced ( Chlamydia pneumoniae -Omp2 aa23-aa93 , Chlamydia psittaci -Omp2 aa23-aa94 , and Chlamydia trachomatis -Omp2 aa23-aa84, aa87-aa547, aa23-aa182, aa167-aa434, aa420-aa547 ). By an enzyme-linked immunosorbent assay with serologically defined patient sera, Omp2 was found to be a major immunogen of both C. pneumoniae and C. trachomatis infections ( P ≪ 0.0001). The humoral immune responses were not confined to any particular region of the Omp2 protein, and no species-specific anti-Omp2 immunoglobulins were detected.

Background Chlamydia trachomatis is the most common cause of sexually transmitted infections globally and the leading cause of preventable blindness in the developing world. There are two biovariants of C. trachomatis: 'trachoma', causing ocular and genital tract infections, and the invasive 'lymphogranuloma venereum' strains. Recently, a new variant of the genital tract C. trachomatis emerged in Sweden. This variant escaped routine diagnostic tests because it carries a plasmid with a deletion. Failure to detect this strain has meant it has spread rapidly across the country provoking a worldwide alert. In addition to being a key diagnostic target, the plasmid has been linked to chlamydial virulence. Analysis of chlamydial plasmids and their cognate chromosomes was undertaken to provide insights into the evolutionary relationship between chromosome and plasmid. This is essential knowledge if the plasmid is to be continued to be relied on as a key diagnostic marker, and for an understanding of the evolution of Chlamydia trachomatis. Results The genomes of two new C. trachomatis strains were sequenced, together with plasmids from six C. trachomatis isolates, including the new variant strain from Sweden. The plasmid from the new Swedish variant has a 377 bp deletion in the first predicted coding sequence, abolishing the site used for PCR detection, resulting in negative diagnosis. In addition, the variant plasmid has a 44 bp duplication downstream of the deletion. The region containing the second predicted coding sequence is the most highly conserved region of the plasmids investigated. Phylogenetic analysis of the plasmids and chromosomes are fully congruent. Moreover this analysis also shows that ocular and genital strains diverged from a common C. trachomatis progenitor. Conclusion The evolutionary pathways of the chlamydial genome and plasmid imply that inheritance of the plasmid is tightly linked with its cognate chromosome. These data suggest that the plasmid is not a highly mobile genetic element and does not transfer readily between isolates. Comparative analysis of the plasmid sequences has revealed the most conserved regions that should be used to design future plasmid based nucleic acid amplification tests, to avoid diagnostic failures.