The application of modern research tools has broadened our understanding of the chlamydiae and their role in disease. Chlamydial genome analysis showed the presence of genes for ATP and peptidoglycan synthesis, contradicting the common belief that chlamydiae lack the ability to produce these compounds. Phylogenetic tree analysis suggests that chlamydiae could have evolved from an intracellular existence in amoebae. Newly discovered obligate intracellular organisms with chlamydia-like life-cycles have been classified as chlamydiae by rRNA homology with existing chlamydial species. A proposed new classification adds three new families to the order Chlamydiales as well as creates two genera and nine species within the family Chlamydiaceae. Chlamydiae are incriminated in an increasingly large spectrum of diseases both in humans and in animals. The emergence of multi-drug resistant C. trachomatis strains forewarns therapeutic problems with this organism. While C. pneumoniae remains a significant respiratory pathogen, the role it plays in the pathogenesis of atherosclerosis and ischaemic heart disease awaits definition.
The microbial aetiology of genital ulcers was studied in 249 patients (241 men and 8 women) attending a Sexually Transmitted Disease Clinic in Kuala Lumpur, Malaysia. Herpes simplex virus type 2 was isolated in 48 (19.2%) patients, Haemophilus ducreyi from 22 (8.8%), Neisseria gonorrhoeae from seven (2.8%) and Chlamydia trachomatis from four (1.6%). Syphilis was diagnosed in 18 (7.2%) patients on the basis of dark field microscopy. Two (0.8%) patients were found to have both chancroid and syphilis and one (0.5%) had both gonorrhoea and syphilis. No organism was isolated in the remaining 151 (61.5%) patients. Overall, the accuracy of clinical diagnosis was 58% for single infection, 67% for herpes, 63% for syphilis, 47% for chancroid and 0% for lymphogranuloma venereum. Therefore, our study confirms the need for laboratory tests to diagnose accurately the aetiology of genital ulcer disease.
BACKGROUND: The 7.5 kb cryptic plasmid of Chlamydia trachomatis has been shown to be a virulence factor in animal models, but its significance in humans still remains unknown. The aim of this study was to investigate the prevalence and potential involvement of the C. trachomatis cryptic plasmid in causing various clinical manifestations; including infertility, reproductive tract disintegrity, menstrual disorder, and polycystic ovarian syndrome (PCOS) among genital C. trachomatis-infected patients.
RESULTS:A tot l of 180 female patients of child bearing age (mean 30.9 years old, IQR:27-35) with gynecological complications and subfertility issues, who visited Obstetrics and Gynecology clinics in Kuala Lumpur, Malaysia were recruited for the study. Prevalence of genital chlamydial infection among these patients was alarmingly high at 51.1% (92/180). Of the 92 chlamydia-infected patients, 93.5% (86/92) were infected with plasmid-bearing (+) C. trachomatis while the remaining 6.5% (6/92) were caused by the plasmid-free (-) variant. Our data showed that genital C. trachomatis infection was associated with infertility issues, inflammation in the reproductive tract (mucopurulent cervicitis or endometriosis), irregular menstrual cycles and polycystic ovarian syndrome (PCOS). However, no statistical significance was detected among patients with plasmid (+) versus plasmid (-) C. trachomatis infection. Interestingly, plasmid (+) C. trachomatis was detected in all patients with PCOS, and the plasmid copy numbers were significantly higher among PCOS patients, relative to non-PCOS patients.
CONCLUSION: Our findings show a high incidence of C. trachomatis infection among women with infertility or gynecological problems in Malaysia. However, due to the low number of plasmid (-) C. trachomatis cases, a significant role of the plasmid in causing virulence in human requires further investigation of a larger cohort.
KEYWORDS: Chlamydia trachomatis; Infertility; Plasmid; Reproductive system disorders
Study site: Obstetrics and Gynecology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
Identification of pregnant women infected with Chlamydia trachomatis is essential to allow early antibiotic treatment in order to prevent adverse pregnancy outcomes. In this study, two nucleic acid amplification tests (NAAT) namely nested PCR (BioSewoom, Korea) and Amplicor CT/NG (Roche Diagnostic, USA) were evaluated in terms of sensitivity and specificity for the detection of C. trachomatis DNA in pregnant women with preterm complications. A cross-sectional study was carried out in two public hospitals in Southern Selangor, Malaysia. Endocervical swabs obtained were subjected to DNA amplification using nested PCR (BioSewoom, Korea) and Amplicor CT/NG (Roche Diagnostic, USA). A total of 83 endocervical swabs obtained from pregnant women of less than 37 weeks gestation and presented with preterm complications were subjected to chlamydial DNA detection using both assays. The study shows that Amplicor CT/NG assay is more effective in the detection of C. trachomatis DNA from endocervical swabs compared to Biosewoom nested PCR kit. Agreement between the two assays were poor (kappa=0.094) with nested PCR showing a low sensitivity of 10.81% and a 97.83% specificity when compared to Amplicor CT/NG. The results obtained indicated that BioSewoom nested PCR was less sensitive than Amplicor CT/ NG for detecting C. trachomatis in endocervical specimens and that another more reliable test is required for confirmatory result.
The cervical microbiota constitutes an important protective barrier against the invasion of pathogenic microorganisms. A disruption of microbiota within the cervical milieu has been suggested to be a driving factor of sexually transmitted infections. These include Chlamydia trachomatis which frequently causes serious reproductive sequelae such as infertility in women. In this study, we profiled the cervical microbial composition of a population of 70 reproductive-age Malaysian women; among which 40 (57.1%) were diagnosed with genital C. trachomatis infection, and 30 (42.8%) without C. trachomatis infection. Our findings showed a distinct compositional difference between the cervical microbiota of C. trachomatis-infected subjects and subjects without C. trachomatis infection. Specifically, significant elevations of mostly strict and facultative anaerobes such as Streptococcus, Megasphaera, Prevotella, and Veillonella in the cervical microbiota of C. trachomatis-positive women were detected. The results from the current study highlights an interaction of C. trachomatis with the environmental microbiome in the endocervical region.
A plasmid construct was designed in which the gene of antimicrobial peptide melittin is controlled by the tetracycline-responsive promoter of human cytomegalovirus, aided by a constitutively expressed trans-activator protein gene. Its vaginal administration and induction of melittin gene transcription with doxycycline markedly suppressed subsequent genital tract infection of mice by Mycoplasma hominis and Chlamydia trachomatis. At least half of the melittin-protected animals proved free of either pathogen within 3-4 weeks. Recombinant plasmids expressing genes of antimicrobial peptides hold much promise as agents for prevention and control of urogenital latent infections.
First-void urine samples collected from sexually transmitted diseases (STD) clinic patients were examined by a nested polymerase chain reaction (PCR) and a commercial enzyme immunoassay (IDEIA Chlamydia) for the diagnosis of Chlamydia trachomatis urethritis or cervicitis. The primers for the PCR amplified a target in the major outer membrane protein (MOMP) gene in C trachomatis while the IDEIA detected genus-specific chlamydial lipopolysaccharide. Discrepant results were resolved by retesting urine specimens with a second (plasmid-based) PCR and taking urethral or endocervical swab results into consideration. For 231 men (chlamydial prevalence 20.4%), the sensitivity, specificity, positive and negative predictive values were 59.6%, 99.5%, 96.6% and 90.6% for urine IDEIA, 68.1%, 99.5%, 97% and 92.4% for urethral swab IDEIA and 97.9%, 99.5%, 97.9% and 99.5% for urine PCR. The corresponding rates for 66 women (chlamydial prevalence 54.6%) were 19.4%, 100%, 100% and 50.8% for urine IDEIA, 86.1%, 96.7%, 96.9% and 85.3% for endocervical swab IDEIA and 91.7%, 93.3%, 94.3% and 90.3% for urine PCR. Hence, in a high prevalence population, the urine IDEIA was a suitable alternative to the male urethral swab IDEIA but significantly less sensitive than the endocervical swab IDEIA. The urine PCR was, however, much more sensitive than the urine IDEIA for both men and women and could replace the endocervical swab IDEIA for the diagnosis of chlamydial cervicitis.