Urogenital chlamydia trachomatis treatment failure with azithromycin: A meta-analysis

Prevalence, incidence and recurrence of sexually transmitted infections in HIV-negative adult women in a rural South African setting

OBJECTIVE

Sexually transmitted infections (STIs), including syphilis, chlamydia, gonorrhoea and trichomoniasis, are of global public health concern. While STI incidence rates in sub-Saharan Africa are high, longitudinal data on incidence and recurrence of STIs are scarce, particularly in rural areas. We determined the incidence rates of curable STIs in HIV-negative women during 96 weeks in a rural South African setting.

METHODS

We prospectively followed participants enrolled in a randomised controlled trial to evaluate the safety and efficacy of a dapivirine-containing vaginal ring for HIV prevention in Limpopo province, South Africa. Participants were included if they were female, aged 18-45, sexually active, not pregnant and HIV-negative. Twelve-weekly laboratory STI testing was performed during 96 weeks of follow-up. Treatment was provided based on vaginal discharge by physical examination or after a laboratory-confirmed STI.

RESULTS

A total of 119 women were included in the study. Prevalence of one or more STIs at baseline was 35.3%. Over 182 person-years at risk (PYAR), a total of 149 incident STIs were diagnosed in 75 (65.2%) women with incidence rates of 45.6 events/PYAR for chlamydia, 27.4 events/100 PYAR for gonorrhoea and 8.2 events/100 PYAR for trichomoniasis. Forty-four women developed ≥2 incident STIs. Risk factors for incident STI were in a relationship ≤3 years (adjusted hazard ratio [aHR]: 1.86; 95% confidece interval [CI]: 1.04-2.65) and having an STI at baseline (aHR: 1.66; 95% CI: 1.17-2.96). Sensitivity and specificity of vaginal discharge for laboratory-confirmed STI were 23.6% and 87.7%, respectively.

CONCLUSION

This study demonstrates high STI incidence in HIV-negative women in rural South Africa. Sensitivity of vaginal discharge was poor and STI recurrence rates were high, highlighting the shortcomings of syndromic management in the face of asymptomatic STIs in this setting.

Design, Biological Evaluation, and Computer-Aided Analysis of Dihydrothiazepines as Selective Antichlamydial Agents

Chlamydia trachomatis (CT) causes the most prevalent sexually transmitted bacterial disease in the United States. The lack of drug selectivity is one of the main challenges of the current antichlamydial pharmacotherapy. The metabolic needs of CT are controlled, among others, by cylindrical proteases and their chaperones (e.g., ClpX). It has been shown that dihydrothiazepines can disrupt CT-ClpXP. Based on this precedent, we synthesized a dihydrothiazepine library and characterized its antichlamydial activity using a modified semi-high-throughput screening assay. Then, we demonstrated their ability to inhibit ClpX ATPase activity in vitro, supporting ClpX as a target. Further, our lead compound displayed a promising selectivity profile against CT, acceptable cytotoxicity, no mutagenic potential, and good in vitro stability. A two-dimensional quantitative structure-activity relationship (2D QSAR) model was generated as a support tool in the identification of more potent antichlamydial molecules. This study suggests dihydrothiazepines are a promising starting point for the development of new and selective antichlamydial drugs.

Controversies and evidence on Chlamydia testing and treatment in asymptomatic women and men who have sex with men: a narrative review

Background

Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection (STI) worldwide. CT is mainly asymptomatic. Test-and-treat strategies are widely implemented to prevent transmission and complications. Strategies are not without controversy in asymptomatic women and men who have sex with men (MSM). Concerns are emerging to test and treat asymptomatic persons for urogenital CT (‘Controversy 1’) and pharyngeal or rectal CT (‘Controversy 2’), whereby testing symptomatic persons is not under debate. Opposed views in CT treatment involve using azithromycin versus doxycycline (‘Controversy 3’). The objective of this review is to provide coverage of these public health and clinical controversies by reviewing the current scientific evidence.

Methods

A literature search was performed using PubMed for relevant publications between 2018 and September 2021, and iterative retrieval of additional relevant publications.

Results

Controversy 1. In women, the majority of asymptomatic CT are at the urogenital site, and detections mostly include viable CT. CT easily transmits to a partner and potentially also between the vaginal and rectal areas; the clinical impact of urogenital CT is established, although risks for adverse outcomes are uncertain. Wide-scale testing in asymptomatic women has not resulted in reduced prevalence. In MSM, evidence for the clinical impact of asymptomatic urogenital CT is lacking. Controversy 2. Rectal CT is common in women diagnosed with urogenital CT, but the clinical impact of asymptomatic rectal CT is uncertain. In MSM, rectal CT is common, and most CT infections are at the rectal site, yet the risk of longer term complications is unknown. In both sexes, pharyngeal CT is uncommon and has no documented clinical impact. Controversy 3. In the treatment of rectal CT, doxycycline has superior effectiveness to azithromycin. Evidence has also accumulated on the harms of test-and-treat strategies.

Conclusions

Current practices vary widely, from widescale test-and-treat approaches to more individual patient- and partner-level case management. Choosing which asymptomatic people to test at what anatomic site, and whether to test or not, requires an urgent (re-)definition of the goals of testing and treating asymptomatic persons. Treatment guidelines are shifting toward universal doxycycline use, and clinical practice now faces the challenge of implementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07171-2.

Test-and-treat is a key strategy in the control of Chlamydia trachomatis (CT). We discuss recent controversies and present scientific evidence regarding urogenital, rectal, and pharyngeal CT test-and-treat strategies in women and in men who have sex with men (MSM). This should inform best practices for the prevention and management of the most common bacterial sexually transmitted infection (STI) worldwide.

Worldwide prevalence of fungal coinfections among COVID-19 patients: a comprehensive systematic review and meta-analysis

Microbial coinfections can increase the morbidity and mortality rates of viral respiratory diseases. Therefore, this study aimed to determine the pooled prevalence of fungal coinfections in coronavirus disease 2019 (COVID-19) patients. Web of Science, Medline, Scopus, and Embase were searched without language restrictions to identify the related research on COVID-19 patients with fungal coinfections from December 1, 2019, to December 30, 2020. A random-effects model was used for analysis. The sample size included 2,246 patients from 8 studies. The pooled prevalence of fungal coinfections was 12.60%. The frequency of fungal subtype coinfections was 3.71% for Aspergillus, 2.39% for Candida, and 0.39% for other. The World Health Organization’s Regional Office for Europe and Regional Office for Southeast Asia had the highest (23.28%) and lowest (4.53%) estimated prevalence of fungal coinfection, respectively. Our findings showed a high prevalence of fungal coinfections in COVID-19 cases, which is a likely contributor to mortality in COVID-19 patients. Early identification of fungal pathogens in the laboratory for COVID-19 patients can lead to timely treatment and prevention of further damage by this hidden infection.

Challenges in Treating Chlamydia trachomatis, Including Rectal Infections: Is It Time to Go Back to Doxycycline?

OBJECTIVE

To evaluate recent publications on efficacy of single-dose azithromycin and 7-day doxycycline when treating Chlamydia trachomatis.

DATA SOURCES

A literature search of MEDLINE, EMBASE, PubMed, and Cochrane library was conducted (1990 to June 13, 2021) using the terms: Chlamydia trachomatis, genital chlamydia, rectal chlamydia, extragenital chlamydia, azithromycin, doxycycline, and treatment guidelines. ClinicalTrials.gov was searched to identify ongoing trials.

STUDY SELECTION AND DATA EXTRACTION

English language studies, including controlled studies, retrospective analyses, systematic reviews, meta-analyses, and case reports, reporting microbiological or clinical outcomes in adolescents and adults were considered.

DATA SYNTHESIS

Systemic reviews and meta-analyses of randomized trials reported azithromycin efficacy of 96% to 97% in genital chlamydia. However, reports of treatment failure have emerged, especially among symptomatic males, with an increased risk of microbiological failure after azithromycin than doxycycline (relative risk = 2.45; 95% CI = 1.36-4.41). Retrospective analyses and prospective observational cohort studies reported lower efficacy range following azithromycin than doxycycline (74%-87% vs 92%-100%, respectively) in rectal chlamydia. First randomized controlled trial comparing azithromycin and doxycycline reported significantly higher microbiological cure following doxycycline, with absolute difference of 26% (95% CI = 16%-36%; P < 0.001). The proposed 2021 Centers for Disease Control and Prevention treatment guidelines designate doxycycline as the preferred agent for treatment at any site.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

A growing body of evidence for treatment failure following azithromycin, especially in rectal chlamydia supports updating current practice.

CONCLUSIONS

Doxycycline continues to achieve high efficacy in genital and rectal chlamydia. Clinicians should consider efficacy with convenience of dosing regimen, medication compliance, and sexual behavior risks when treating chlamydia infections.

In vitro inhibitory effect of Hydrocotyle bonariensis Lam. extracts over Chlamydia trachomatis and Chlamydia pneumoniae on different stages of the chlamydial life cycle

Chlamydial infections in humans are widely distributed and are responsible for a variety of acute and chronic diseases. Both Chlamydia trachomatis and Chlamydia pneumoniae can lead to chronic conditions that have been linked to complications and sequelae. This study aimed to develop a culture method in order to detect in vitro antichlamydial activity of different extracts obtained from native Argentinian plants used as antimicrobials in local ethnomedicine and to evaluate their inhibitory activity over Chlamydia trachomatis and Chlamydia pneumoniae growth. The inhibitory activity over different stages of the chlamydial life cycle on cell culture was assessed: the entry, the inclusion developing after entry, and the exponential growth stage. Also, the capability of rendering the cell refractory to chlamydial infection by pre-incubation with the extracts was assayed. Inhibitory activity of water-based and organic-based extracts obtained from Hydrocotyle bonariensis Lam. (Araliaceae), Lithraea molleoides (Vell.) Engl. (Anacardiaceae) and Hybanthus parviflorus (Mutis ex L.f.) Baill. (Violaceae) were tested against five strains of Chlamydia trachomatis (L2/434/BU and four clinical isolates form both neonatal conjunctivitis and adult genital infections, genotypes D, E, and K) and against Chlamydia pneumoniae AR39. The Hydrocotyle bonariensis dichloromethane extract showed a broad inhibitory activity over the exponential growth stage of Chlamydia trachomatis and Chlamydia pneumoniae independently from the chlamydial strain and the cell line. These results suggest a high inhibitory potential on both Chlamydiae species. In order to characterize the Hydrocotyle bonariensis dichloromethane active extract, an ¹H-NMR was performed. The ¹H-NMR characterization showed a spectrum with characteristic signals of the fatty acid moiety of lipids or cerebrosides, volatile phenolics, phytosterols, methyl triterpenes signals, and glucose moiety of the cerebrosides.

In-cell western assay as a high-throughput approach for Chlamydia trachomatis quantification and susceptibility testing to antimicrobials

Chlamydia trachomatis, the leading cause of bacterial sexually transmitted diseases in developed countries, with around 127 million new cases per year, is mainly responsible for urethritis and cervicitis in women, and urethritis and epididymitis in men. Most C. trachomatis infections remain asymptomatic (>50%) and, hence, untreated, leading to severe reproductive complications in both women and men, like infertility. Therefore, the detection of C. trachomatis as well as the antimicrobial susceptibility testing becomes a priority, and, along the years, several methods have been recommended, like cell culture and direct immunofluorescence (DFA) on cell cultures. Herein, we described the application of In-Cell Western assay (ICW) via Odyssey CLx as a fast, more accessible, and high-throughput platform for the quantification of C. trachomatis and the screening of anti-chlamydial drugs. As a first step, we set up a standard curve by infecting cell monolayers with 2-fold serial dilutions of C. trachomatis Elementary Body (EB) suspension. Then, different unknown C. trachomatis EB suspensions were quantified and the chlamydial susceptibility testing to erythromycin was performed, using the DFA as comparison. Our results showed a very high concordance between these two assays, as evidenced by the enumeration of chlamydial IFUs as well as the determination of erythromycin Minimum Inhibitory Concentration (MIC). In conclusion, the ICW assay may be a promising candidate as an accurate and accessible methodology for C. trachomatis antimicrobial susceptibility testing.

Identification of differentially expressed genes and signaling pathways in human conjunctiva and reproductive tract infected with Chlamydia trachomatis

Background

Currently, Chlamydia trachomatis–specific host defense mechanisms in humans remain poorly defined. To study the characteristics of host cells infected early with Chlamydia trachomatis, we used bioinformatics methods to analyze the RNA transcription profiles of the conjunctiva, fallopian tubes, and endometrium in humans infected with Chlamydia trachomatis.

Method

The gene expression profiles of GSE20430, GSE20436, GSE26692, and GSE41075 were downloaded from the Gene Expression Synthesis (GEO) database. Then, we obtained the differentially expressed genes (DEGs) through the R 4.0.1 software. STRING was used to construct protein–protein interaction (PPI) networks; then, the Cytoscape 3.7.2 software was used to visualize the PPI and screen hub genes. GraphPad Prism 8.0 software was used to verify the expression of the hub gene. In addition, the gene–miRNA interaction was constructed on the NetworkAnalyst 3.0 platform using the miRTarBase v8.0 database.

Results

A total of 600 and 135 DEGs were screened out in the conjunctival infection group and the reproductive tract infection group, respectively. After constructing a PPI network and verifying the hub genes, CSF2, CD40, and CSF3 in the reproductive tract infection group proved to have considerable statistical significance.

Conclusion

In our research, the key genes in the biological process of reproductive tract infection with Chlamydia trachomatis were clarified through bioinformatics analysis. These hub genes may be further used in clinical treatment and clinical diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40246-021-00313-8.