Chlamydial conjunctivitis: prevalence and serovar distribution of Chlamydia trachomatis in adults

Ensuring equity with pre-clinical planning for chlamydia vaccines

Chlamydia trachomatis (Ct) remains the most common bacterial sexually transmitted pathogen worldwide, causing significant morbidity particularly among women, including pelvic inflammatory disease, ectopic pregnancy, and infertility. Several vaccines are advancing through pre-clinical and clinical development, and it is likely that one or more vaccines will progress into human efficacy trials soon. In this Perspective, we present a case for considering the challenges of Ct vaccine development through a lens of equity and justice. These challenges include the need to protect against multiple serovars, in both females and males, at multiple anatomic sites, and in resource poor areas of the world. We propose that early consideration of vaccine implementation by conducting community-engaged research will ensure that a scientifically sound chlamydia vaccine promotes equity, justice, and shared-gendered responsibility for STI prevention.

Identification and characterization of mixed infections of Chlamydia trachomatis via high-throughput sequencing

Precise genotyping is necessary to understand epidemiology and clinical manifestations of Chlamydia trachomatis infection with different genotypes. Next-generation high-throughput sequencing (NGHTS) has opened new frontiers in microbial genotyping, but has been clinically characterized in only a few settings. This study aimed to determine C. trachomatis genotypes in particular mixed-genotype infections and their association with clinical manifestations and to characterize the sensitivity and accuracy of NGHTS. Cervical specimens were collected from 8,087 subjects from physical examination center (PEC), assisted reproductive technology center (ART) and gynecology clinics (GC) of Chenzhou Hospital of China. The overall prevalence of C. trachomatis was 3.8% (311/8087) whereas a prevalence of 2.8, 3.7 and 4.8% was found in PEC, ART and GC, respectively. The most frequent three C. trachomatis genotypes were E (27.4%, 83/303), F (21.5%, 65/303) and J (18.2%, 55/303). Moreover, NGHTS identified 20 (6.6%, 20/303) mixed-genotype infections of C. trachomatis. Genotype G was more often observed in the subjects with pelvic inflammatory disease than genotype E (adjusted OR = 3.61, 95%CI, 1.02–12.8, p = 0.046). Mixed-genotype infection was associated with severe vaginal cleanliness (degree IV) with an adjusted OR of 5.17 (95%CI 1.03–25.9, p = 0.046) whereas mixed-genotype infection with large proportion of minor genotypes was associated with cervical squamous intraepithelial lesion (SIL) with an adjusted OR of 5.51 (95%CI 1.17–26.01, p = 0.031). Our results indicated that NGHTS is a feasible tool to identity C. trachomatis mixed-genotype infections, which may be associated with worse vaginal cleanliness and cervical SIL.

Bacterial eye infections associated with sexual transmission infections: A review

The objective of this work was to collect updated information on Treponema pallidum, Chlamydia trachomatis and Neisseria gonorrhoeae, causing sexually transmitted infections (STIs) and etiological agents of eye infections, to provide relevant information on this public health problem. For this, a bibliographic review was carried out using different electronic databases such as: PubMed central, google academic, Lilacs, Scopus, Science Direct and Scielo, between March 2009 and August 2019. According to the WHO, more than a million people a day contract a sexually transmitted infection. For T. pallidum, a global prevalence of 0.5% is estimated for both men and women. It is a causative agent of syphilis and ocular syphilis, which manifests as uveitis. Overall, a prevalence of 2.8% in men and 3.8% in women for C. trachomatis is estimated. It is associated with oculo-genital disease, which includes STIs, inclusion conjunctivitis in adults and neonatal ophthalmia. Among its complications is trachoma, which is the leading cause of infectious blindness worldwide. Regarding N. gonorrhoeae, it has a global selection of 0.9% and 0.7% in women and men, respectively. It manifests with gonococcal conjunctivitis and neonatal ophthalmia. We can conclude that the information that relates T. pallidum, C. trachomatis and N. gonorrhoeae with their ocular compromise problems is insufficient, and even more so if we seek to find them related to each other, which makes it difficult to access data of clinical utility for visual health.

Structure-based drug target prioritisation and rational drug design for targeting Chlamydia trachomatis eye infections

Chlamydia trachomatis (C.t) is a major causative of infectious blindness in world. It is a real challenge to combat Chlamydial infection as it is an intracellular pathogen. Hence, it is essential to determine the most potential targets of C.t in order to inhibit or suppress its virulence during its infectious phase. Thus, in this study, the highly expressed-cum-most essential genes reported through our earlier study were reprioritized by structure-based comparative binding site analysis with host proteome. Therefore, computational approaches involving molecular modelling, large-scale binding site prediction and comparison, molecular dynamics simulation studies were performed to narrow down the most potential targets. Furthermore, high-throughput virtual screening and ADMETox were also performed to identify potential hits that shall efficiently inhibit the prioritised targets. Hence, by this study we report Pyruvoyl-dependent arginine decarboxylase (PvlArgDC), DNA-repair protein (RecO) and porin (outer membrane protein) as the most viable targets of C.t which can be potentially targeted by compounds, NSC_13086, MFCD00276409, MFCD05662003, respectively. AbbreviationsC.tChlamydia trachomatisSTDSexually transmitted diseaseHTVSHigh-throughput virtual screeningADMEToxAbsorption, Distribution, Metabolism, Excretion and ToxicityPMPocketMatchMDMolecular Dynamics simulationSPStandard precisionXPExtra precisionMMGBSAMolecular mechanics energies combined with generalised Born and surface area continuum solvationOMPOuter membrane proteinPvlArgDCPyruvoyl-dependent arginine decarboxylaseRecORecombination protein O.Communicated by Ramaswamy H. Sarma.

Adult conjunctivitis secondary to dual infection with Chlamydia trachomatis and Neisseria gonorrhoeae - A case report

Purpose

Although Chlamydia trachomatis and Neisseria gonorrhoeae are the commonest sexually transmitted infections in England, reports of ocular co-infection in the literature are limited. We report such a case which responded well to treatment, and discuss the literature and evidence currently available with regards to management of these cases.

Observations

The patient is a 48-year-old bisexual gentleman who presented to the eye clinic of a UK hospital with redness, discharge and blurred vision in his left eye for one week. Initially he had mucopurulent discharge but his cornea was clear. He did not comply with prescribed treatment and returned two days later with bilateral symptoms and corneal thinning in his left eye peripherally.PCR tests for Chlamydia trachomatis and Neisseria gonorrhoeae were positive and the patient was commenced on intravenous ceftriaxone, oral and topical levofloxacin eye drops. After 48 hours of inpatient treatment the patient showed clinical improvement.

Conclusions and importance

Ophthalmologists should be aware of the possibility that Chlamydia trachomatis and Neisseria gonorrhoeae can cause co-infection in adult conjunctivitis, and of the straightforward method of treatment for such individuals. Delayed diagnosis and treatment of affected patients can lead to corneal complications and potential blindness. It is advisable to discuss these cases with the local microbiology service wherever possible, and referral to a sexual health service is imperative.

Comparison of reverse hybridization and ompA sequencing methods applied on Chlamydia trachomatis strains from Tunisia

Two techniques based on ompA amplification of Chlamydia trachomatis were compared, being reverse hybridization (RHM) and ompA sequencing (OSA), to investigate the concordance between them and to study the epidemiological relevance of each method. In addition, phylogenetic analysis was performed on the ompA sequences. One hundred and seven C. trachomatis positive samples from Tunisian patients and female sex workers were analyzed using both the RHM and ompA sequencing. The overall genovar distribution obtained with both techniques was very similar. The RHM identified nine genovars, being B, D, E, F, G, H, I, J and K, where B, I, J, and K were only found in mixed infections versus 7 types for the OSA being D, E, F, G, H, I, and K. The agreement between both typing techniques was 87.8%. Both methods showed that genovar E was the most predominant type. In 24.3% of the analyzed samples, mixed infections were detected. In 96.1% of these, the genovar identified by OSA was also detected using the RHM. OmpA sequencing allowed determination of six genovar types that could not be typed using RHM. The analyses of ompA nucleotide variation in the 107 clinical specimens detected ompA genovar variants with distinct ompA mutational patterns for types D2, G1, G2, and H1. In conclusion, RHM and OSA showed a high agreement in C. trachomatis genotyping results with each having their specific benefits.