Comparison of four serological assays for the diagnosis of Chlamydia trachomatis in subfertile women

Introduction: Chlamydia antibody testing (CAT) in serum has been introduced as a screening method in the infertility workup. We evaluated the test characteristics of two ELISA tests compared to micro-immunofluorescence tests (MIFs). MIFs are considered the gold standard in the C. trachomatis IgG antibodies detection. We also compared the accuracy of all CAT tests in predicting tubal subfertility, using laparoscopy as a reference. Methodology: Four commercial serological methods were used to analyse 101 serum samples for the presence of C. trachomatis IgG antibodies from patients at the Infertility Clinic of Ghent University Hospital. The diagnostic utility for prediction of tubal infertility of serological methods was evaluated based on patients' medical records. Results: A comparison of the serological assays showed little difference in the major performance characteristics: the sensitivities of all MIFs and ELISAs were 100% for all assays (except the ELISA Vircell, with a sensitivity of 90%), and the specificities ranged from 92% for MIF Ani Labsystems to 98% for the MIF Focus and ELISA Vircell. As compared to laparoscopy data, CAT positivity in subfertile women with tubal damage (n=40) did not significantly differ from that of subfertile women without tubal damage (n=61): Positive predictive values (PPV) of CAT ranged from 53% to 60% and negative predictive values (NPV) ranged from 62% to 64%. Conclusion: evaluated ELISAs are comparable to MIFs in the detection of C. trachomatis IgG antibodies and should be preferred for large serological studies, especially in resource poor settings

Chlamydial infection from outside to inside

Chlamydia are obligate intracellular bacteria, characterized by a unique biphasic developmental cycle. Specific interactions with the host cell are crucial for the bacteria's survival and amplification because of the reduced chlamydial genome. At the start of infection, pathogen-host interactions are set in place in order for Chlamydia to enter the host cell and reach the nutrient-rich peri-Golgi region. Once intracellular localization is established, interactions with organelles and pathways of the host cell enable the necessary hijacking of host-derived nutrients. Detailed information on the aforementioned processes will increase our understanding on the intracellular pathogenesis of chlamydiae and hence might lead to new strategies to battle chlamydial infection. This review summarizes how chlamydiae generate their intracellular niche in the host cell, acquire host-derived nutrients in order to enable their growth and finally exit the host cell in order to infect new cells. Moreover, the evolution in the development of molecular genetic tools, necessary for studying the chlamydial infection biology in more depth, is discussed in great detail

The role of serological testing for <i>Chlamydia trachomatis</i> in differential diagnosis of pelvic pain

Introduction Pelvic pain is typically associated with pelvic inflammatory disease (PID). The most common cause of PID is Chlamydia trachomatis . The aim of this study was to verify the role of serological testing for Chlamydia trachomatis in patients with suspected PID. Material and Methods The retrospective study included 185 patients with pelvic pain hospitalized at the Department of Obstetrics and Gynecology in 2003 and 2004. Titers of anti- Chlamydia trachomatis IgG and IgA were measured by means ELISA immunoassays. Erythrocyte sedimentation rate (ESR), serum concentration of C-reactive protein (CRP) and leukocyte count (WBC) were also determined. Final diagnosis was established on the basis of laparoscopic examination. Results The presence of anti- Chlamydia trachomatis antibodies correlated significantly with abnormal values of ESR, WBC and CRP. The most common laparoscopic pathology were pelvic adhesions, typically found in women with elevated titers of anti- Chlamydia trachomatis IgG. Conclusions Serological examination for Chlamydia trachomatis is helpful in evaluation of patients with suspected PID. Elevated titers of anti- Chlamydia trachomatis antibodies are frequently associated with laparoscopic evidence of pelvic adhesions and inflammation

Penicillin kills chlamydia following the fusion of bacteria with Lysosomes and prevents genital inflammatory lesions in C. muridarum-infected mice

The obligate intracellular bacterium Chlamydia exists as two distinct forms. Elementary bodies (EBs) are infectious and extra-cellular, whereas reticulate bodies (RBs) replicate within a specialized intracellular compartment termed an ‘inclusion’. Alternative persistent intra-cellular forms can be induced in culture by diverse stimuli such as IFNγ or adenosine/EHNA. They do not grow or divide but revive upon withdrawal of the stimulus and are implicated in several widespread human diseases through ill-defined in vivo mechanisms. β-lactam antibiotics have also been claimed to induce persistence in vitro. The present report shows that upon penicillin G (pG) treatment, inclusions grow as fast as those in infected control cells. After removal of pG, Chlamydia do not revert to RBs. These effects are independent of host cell type, serovar, biovar and species of Chlamydia. Time-course experiments demonstrated that only RBs were susceptible to pG. pG-treated bacteria lost their control over host cell apoptotic pathways and no longer expressed pre-16S rRNA, in contrast to persistent bacteria induced with adenosine/EHNA. Confocal and live-video microscopy showed that bacteria within the inclusion fused with lysosomal compartments in pG-treated cells. That leads to recruitment of cathepsin D as early as 3 h post pG treatment, an event preceding bacterial death by several hours. These data demonstrate that pG treatment of cultured cells infected with Chlamydia results in the degradation of the bacteria. In addition we show that pG is significantly more efficient than doxycycline at preventing genital inflammatory lesions in C. muridarum-C57Bl/6 infected mice. These in vivo results support the physiological relevance of our findings and their potential therapeutic applications

Protection of outbred mice against a vaginal challenge by a Chlamydia trachomatis serovar E recombinant major outer membrane protein vaccine is dependent on phosphate substitution in the adjuvant.

Chlamydia trachomatis is the most common bacterial sexually-transmitted pathogen for which there is no vaccine. We previously demonstrated that the degree of phosphate substitution in an aluminum hydroxide adjuvant in a TLR-4-based C. trachomatis serovar E (Ser E) recombinant major outer membrane protein (rMOMP) formulation had an impact on the induced antibody titers and IFN-γ levels. Here, we have extended these observations using outbreed CD-1&nbsp;mice immunized with C. trachomatis Ser E rMOMP formulations to evaluate the impact on bacterial challenge. The results confirmed that the rMOMP vaccine containing the adjuvant with the highest phosphate substitution induced the highest neutralizing antibody titers while the formulation with the lowest phosphate substitution induced the highest IFN-γ production. The most robust protection was observed in mice vaccinated with the formulation containing the adjuvant with the lowest phosphate substitution, as shown by the number of mice with positive vaginal cultures, number of positive cultures and number of C. trachomatis inclusion forming units recovered. This is the first report showing that vaccination of an outbred strain of mice with rMOMP induces protection against a vaginal challenge with C. trachomatis

Chlamydia trachomatis infection and the risk of perinatal mortality in Hungary

Introduction: Chlamydial infections of the genital tract are thought to often lead to preterm birth, which is the most important perinatal problem in Hungary. Aim of study: A multicenter study was carried out to determine the prevalence of Chlamydia trachomatis infection, risk factors for the infection and to relate the infection to perinatal mortality, accounting for potential confounding effects. Methods: The nucleic acid hybridization method (PACE2 Gen-Probe) was applied for the examination of Chlamydia trachomatis. Logistic regression analysis was used to assess risk. Results: A total of 6156 pregnant women were examined for the occurrence of Chlamydia trachomatis. The observed overall rate of chlamydial infection was 5.9%. Young age (less than 24 years old) (OR and 95% CI:1.6 (1.3-2.0)), unmarried status (1.5 (1.2-1.9)) and the high unemployment rate (2.1 (1.6-2.7)) were statistically significant predictors of the infection. In logistic regression analysis, chlamydial infection (1.9 (1.1-3.3)). high unemployment rate (1.5 (1.2-2.2)) and low birth weight (1.7 (1.1-2.7) were significant predictors of perinatal mortality. Conclusions: Testing pregnant women for diseases that can be transmitted perinatally is an important part of obstetric cart. Screening for C. trachomatis of unmarried women under 24 years of age is suggested and need increased observation during labor

National Institute of Allergy and Infectious Diseases workshop report: "Chlamydia vaccines: The way forward".

Chlamydia trachomatis (Ct), an intracellular pathogen, is the most common bacterial sexually transmitted infection. In addition to acute cervicitis and urethritis, Ct can lead to serious sequelae of significant public health burden including pelvic inflammatory disease (PID) and infertility. Ct control efforts have not resulted in desired outcomes such as reduced incidence and reinfection, and this highlights the need for the development of an effective Ct vaccine. To this end, NIAID organized a workshop to consider the current status of Ct vaccine research and address critical questions in Ct vaccine design and clinical testing. Topics included the goal(s) of a vaccine and the feasibility of achieving these goals, animal models of infection including mouse and nonhuman primate (NHP) models, and correlates of protection to guide vaccine design. Decades of research have provided both whole cell-based and subunit vaccine candidates for development. At least one is currently in clinical development and efforts now need to be directed toward further development of the most attractive candidates. Overall, the discussions and presentations from the workshop highlighted optimism about the current status of Ct vaccine research and detailed the remaining gaps and questions needed to move vaccines forward

Distribution of Chlamydia trachomatis genotypes in infertile patients of Cordoba, Argentina

To detect and characterize Chlamydia trachomatis (C. trachomatis) genotypes in infertile patients of Córdoba, Argentina; 660 endocervical and urethral swabs and semen samples were collected from infertile patients for detection of C. trachomatis by omp A gene with Hemi Nested-PCR and cryptic plasmid-PCR. Sequencing methods of omp A gene were used to identify C. trachomatis genotypes. The sequences obtained were aligned with chlamydial sequences currently available in the GenBank, for the design of the phylogenetic tree. The prevalence of C. trachomatis was 7.27% (48/660). We did not detect C. trachomatis cryptic plasmid free strains. According to the results of nucleotide sequences, the distribution of genotypes was L1 (50 %) followed by G (25 %), E (12.5%) and D (12.5%). Patients who tested positive to genotype L1 had no symptoms of lymphogranuloma venereum (LGV). This is the first study that provides information about the distribution of C. trachomatis genotypes and the circulation of cryptic plasmid negative strains of C. trachomatis among patients with infertility in Córdoba, Argentina.Fil: Monetti, Marina Soledad. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Molina, Rosa Alejandra. Laboratorio de Andrología y Reproducción; ArgentinaFil: Estofan, Patricia. Centro Integral de Ginecología, Obstericia y Reproducción; ArgentinaFil: Frutos, Maria Celia. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kiguen, Ana Ximena. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Venezuela, Raul Fernando. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Virología; ArgentinaFil: Paglini, Maria Gabriela. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cuffini, Cecilia Gabriela. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin