Prevalence of plasmid-bearing and plasmid-free Chlamydia trachomatis infection among women who visited obstetrics and gynecology clinics in Malaysia

Abstract

BackgroundThe 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.ResultsA total 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.ConclusionOur 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.

Comparative study in infertile couples with and without Chlamydia trachomatis genital infection

“…It is slightly lower than previous published reports, which showed varied prevalence rates of between 1% and 93.5% [17–19]. Discrepancies of the findings in these studies might be due to the fact that almost all of the sub-infertile patients in our study have a regular sexual partner, and were asymptomatic prior to the study.…”

Nonpathogenic Colonization with Chlamydia in the Gastrointestinal Tract as Oral Vaccination for Inducing Transmucosal Protection

“…Finally, mutant C. muridarum strains that are attenuated in inducing a pathology in the mouse upper genital tract have been identified (57,58), suggesting that these mutants can be safer oral vaccines. However, although attenuated plasmid-free C. trachomatis strains have been identified or created (59)(60)(61)(62)(63)(64)(65), neither their safety nor their efficacy after they are orally taken up into the human GI tract is known.…”

The Nature and Extent of Plasmid Variation in Chlamydia trachomatis

“…Plasmid DNA tends to be present in multiple copies, thus targeting sequences within the plasmid affords a greater sensitivity of detection than chromosomal sites. However, the plasmid is accessory to survival; plasmid-free C. trachomatis isolates have been detected in clinical samples, although they are extremely rare [37,43,44,81,82]. It has previously been suggested that the plasmid might be a poor diagnostic target due to the opportunity for homologous recombination between plasmids and exchange of plasmids between isolates [35]; however, these events are infrequent.…”