Randomized, double-blind, multicenter safety and efficacy study of rifalazil compared with azithromycin for treatment of uncomplicated genital Chlamydia trachomatis infection in women

Therapeutic efficacy of rifalazil (KRM-1648) in a M. ulcerans-induced Buruli ulcer mouse model

Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans infection that requires long-term antibiotic treatment and/or surgical excision. In this study, we investigated the therapeutic efficacy of the rifamycin derivative, rifalazil (RLZ) (also known as KRM-1648), in an advanced M. ulcerans infection model. Six-week-old female BALB/c mice were infected with 3.25 x 10⁴ colony-forming units (CFU) of M. ulcerans subcutaneously into the bilateral hind footpads. At 33 days post-infection, when the footpads exhibited significant redness and swelling, mice were treated orally with 5 or 10 mg/kg of RLZ for up to 15 weeks. Mice were followed for an additional 15 weeks following treatment cessation. Untreated mice exhibited a progressive increase in footpad redness, swelling, and erosion over time, and all untreated mice reached to endpoint within 5–8 weeks post-bacterial injection. In the RLZ-treated mice, footpad redness and swelling and general condition improved or completely healed, and no recurrence occurred following treatment cessation. After 3 weeks of treatment, the CFU counts from the footpads of recovered RLZ-treated mice showed a 10⁴ decrease compared with those of untreated mice. We observed a further reduction in CFU counts to the detection limit following 6 to 15 weeks of treatment, which did not increase 15 weeks after discontinuing the treatment. Histopathologically, bacteria in the treated mice became fragmented one week after RLZ-treatment. At the final point of the experiment, all the treated mice (5mg/kg/day; n = 6, 10mg/kg/day; n = 7) survived and had no signs of M. ulcerans infection. These results indicate that the rifamycin analogue, RLZ, is efficacious in the treatment of an advanced M. ulcerans infection mouse model.

Diagnosis and Management of Uncomplicated Chlamydia trachomatis Infections in Adolescents and Adults: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

To prepare for the development of the 2021 Centers for Disease Control and Prevention (CDC) sexually transmitted infections treatment guidelines, the CDC convened a committee of expert consultants in June 2019 to discuss recent abstracts and published literature on the epidemiology, diagnosis, and management of sexually transmitted infections.This paper summarizes the key questions, evidence, and recommendations for the diagnosis and management of uncomplicated Chlamydia trachomatis (CT) infections in adolescents and adults that were reviewed and discussed for consideration in developing the guidelines. The evidence reviewed mostly focused on efficacy of doxycycline and azithromycin for urogenital, rectal, and oropharyngeal CT infection, CT risk factors in women, performance of CT nucleic acid amplification tests on self-collected meatal specimens in men, and performance of newer CT point-of-care tests.

A Comparative Insight on the Newly Emerging Rifamycins: Rifametane, Rifalazil, TNP-2092 and TNP-2198

Rifamycins are considered a milestone for tuberculosis (TB) treatment because of their proficient sterilizing ability. Currently, available TB treatments are complicated and need a long duration, which ultimately leads to failure of patient compliance. Some new rifamycin derivatives, i.e., rifametane, TNP-2092 (rifamycin-quinolizinonehybrid), and TNP-2198 (rifamycin-nitromidazole hybrid) are under clinical trials, which are attempting to overcome the problems associated with TB treatment. The undertaken review is intended to compare the pharmacokinetics, pharmacodynamics and safety profiles of these rifamycins, including rifalazil, another derivative terminated in phase II trials, and already approved rifamycins. The emerging resistance of microbes is an imperative consideration associated with antibiotics. Resistance development potential of microbial strains against rifamycins and an overview of chemistry, as well as structure-activity relationship (SAR) of rifamycins, are briefly described. Moreover, issues associated with rifamycins are discussed as well. We expect that newly emerging rifamycins shall appear as potential tools for TB treatment in the near future.

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

Background

Chlamydia Trachomatis is one of the most common pathogens transmitted through the genital tract in humans that leads to urogenital infection.

Objective

Given the high prevalence of chlamydia infection and its adverse effects on the health of women and men, the present meta-analysis was conducted to determine the rate of treatment failure with azithromycin.

Materials and Methods

Databases including MEDLINE, ISI - Web of Science, PubMed, EMBASE, Scopus, ProQuest, and Science Direct were searched for articles published between 1991 and 2018. The quality of the selected articles was assessed using the Cochrane risk of bias assessment tool. Heterogeneity was determined using the I2 and Cochrane Q-Test. Subgroup analysis and meta-regression were used to compare the prevalence rates on different levels of the variables.

Results

A total of 21 articles that met the inclusion criteria were ultimately assessed. The pooled estimate of azithromycin failure rate was 11.23% (CI 95%: 8.23%-14.24%). Also, the azithromycin failure rate was 15.87% (CI 95%: 10.20%-21.54%) for the treatment of urethritis, 7.41% (CI 95%: 0.60%-14.22%) for cervicitis, and 7.14% (CI 95%: 10.90%-3.39%) for genital chlamydia. The pooled estimate of failure rate difference was 2.37% (CI 95%: 0.68%-4.06%), which shows that azithromycin has a higher failure rate in the treatment of chlamydia compared to doxycycline and other examined medications. The meta-regression results showed that the patient's age contributes significantly to the heterogeneity for azithromycin treatment failure rate (β░=░0.826; p░=░0.017).

Conclusion

Azithromycin has a higher failure rate than doxycycline and other studied medications in treating urogenital chlamydia infections.

Non-standard treatment for uncomplicated Chlamydia trachomatis urogenital infections: a systematic review

OBJECTIVES

To review the literature for non-standard treatment options for uncomplicated Chlamydia trachomatis (CT) infections in adolescents and adults.

DESIGN

Systematic review.

DATA SOURCES

Ovid MEDLINE/PubMed, Ovid EMBASE, Cochrane Trials & Systematic Review Databases, CINAHL Plus with Full Text, Web of Science Core Collection, Scopus, ProQuest Dissertations & Theses Global, ClinicalTrials.gov and Health Canada Trials Database were searched for studies in English or French from 1 January 2006 to 6 August 2017. Keywords included CT, anti-infective or anti-bacterial agents, therapy/pharmacotherapy/management.

REVIEW METHODS

Included were primary research studies. Outcome measures included clinical or microbiological cure, treatment failure and adverse events. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were assessed for risk of bias using the Revised Cochrane Risk of Bias V.2.0 tool for randomised and the Newcastle-Ottawa Quality Assessment Scale for non-randomised studies.

FUNDING SOURCE

Public Health Agency of Canada.

RESULTS

Of the 6899 records identified through the database search, 11 studies were included. One randomised controlled trial reported that delayed release doxycycline was non-inferior to azithromycin. Two studies examined higher doses of azithromycin but reported no additional benefit. One study looked at a 5-day azithromycin treatment regimen and reported a high cure rate. Two studies reported efficacy of sitafloxacin, and a single study supports the use of levofloxacin. Two phase 2 studies reported efficacy of single-dose rifalazil in both men and women. Only one retrospective study was identified that examined treatment in pregnant women and reported that efficacy with single-dose azithromycin exceeded that of amoxicillin and erythromycin. A single study examining the efficacy of a beta-lactam antibiotic was stopped early due to high treatment failures.

CONCLUSIONS

The paucity of existing data highlights the need for further adequately powered studies to evaluate rifalazil, delayed release doxycycline, levofloxacin and other agents for the treatment of uncomplicated CT infections.

PROSPERO REGISTRATION NUMBER

CRD42017073096.

Bacterial Transcription as a Target for Antibacterial Drug Development

Transcription, the first step of gene expression, is carried out by the enzyme RNA polymerase (RNAP) and is regulated through interaction with a series of protein transcription factors. RNAP and its associated transcription factors are highly conserved across the bacterial domain and represent excellent targets for broad-spectrum antibacterial agent discovery. Despite the numerous antibiotics on the market, there are only two series currently approved that target transcription. The determination of the three-dimensional structures of RNAP and transcription complexes at high resolution over the last 15 years has led to renewed interest in targeting this essential process for antibiotic development by utilizing rational structure-based approaches. In this review, we describe the inhibition of the bacterial transcription process with respect to structural studies of RNAP, highlight recent progress toward the discovery of novel transcription inhibitors, and suggest additional potential antibacterial targets for rational drug design.

Azithromycin versus Doxycycline for Urogenital Chlamydia trachomatis Infection

BACKGROUND

Urogenital Chlamydia trachomatis infection remains prevalent and causes substantial reproductive morbidity. Recent studies have raised concern about the efficacy of azithromycin for the treatment of chlamydia infection.

METHODS

We conducted a randomized trial comparing oral azithromycin with doxycycline for the treatment of urogenital chlamydia infection among adolescents in youth correctional facilities, to evaluate the noninferiority of azithromycin (1 g in one dose) to doxycycline (100 mg twice daily for 7 days). The treatment was directly observed. The primary end point was treatment failure at 28 days after treatment initiation, with treatment failure determined on the basis of nucleic acid amplification testing, sexual history, and outer membrane protein A (OmpA) genotyping of C. trachomatis strains.

RESULTS

Among the 567 participants enrolled, 284 were randomly assigned to receive azithromycin, and 283 were randomly assigned to receive doxycycline. A total of 155 participants in each treatment group (65% male) made up the per-protocol population. There were no treatment failures in the doxycycline group. In the azithromycin group, treatment failure occurred in 5 participants (3.2%; 95% confidence interval, 0.4 to 7.4%). The observed difference in failure rates between the treatment groups was 3.2 percentage points, with an upper boundary of the 90% confidence interval of 5.9 percentage points, which exceeded the prespecified absolute 5-percentage-point cutoff for establishing the noninferiority of azithromycin.

CONCLUSIONS

In the context of a closed population receiving directly observed treatment for urogenital chlamydia infection, the efficacy of azithromycin was 97%, and the efficacy of doxycycline was 100%. The noninferiority of azithromycin was not established in this setting. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT00980148.).

Background review for the '2015 European guideline on the management of Chlamydia trachomatis infections'

SummaryChlamydia trachomatis infections are major public health concerns globally. Of particular grave concern is that the majority of persons with anogenital Chlamydia trachomatis infections are asymptomatic and accordingly not aware of their infection, and this silent infection can subsequently result in severe reproductive tract complications and sequelae. The current review paper provides all background, evidence base and discussions for the 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS 2015). Comprehensive information and recommendations are included regarding the diagnosis, treatment and prevention of anogenital, pharyngeal and conjunctival Chlamydia trachomatis infections in European countries. However, Chlamydia trachomatis also causes the eye infection trachoma, which is not a sexually transmitted infection. The 2015 European Chlamydia trachomatis guideline provides up-to-date guidance regarding broader indications for testing and treatment of Chlamydia trachomatis infections; clearer recommendation of using validated nucleic acid amplification tests only for diagnosis; advice on (repeated) Chlamydia trachomatis testing; recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection and recommendations to identify, verify and report Chlamydia trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of Chlamydia trachomatis patients are crucial to control its spread.

Treatment of Chlamydial infections: 2014 update

INTRODUCTION

Chlamydiae are obligate intracellular bacterial pathogens whose entry into mucosal epithelial cells is required for intracellular survival and subsequent growth. The life cycle of Chlamydia spp. and the ability to cause persistent, often subclinical infection, has major ramifications for diagnosis and treatment of Chlamydia trachomatis and C. pneumoniae infections in humans.

AREAS COVERED

This paper reviews the current literature on the antimicrobial susceptibilities and treatment of genital infections due to C. trachomatis and respiratory infections due to C. pneumoniae published since 2011.

EXPERT OPINION

Chlamydiae are susceptible to antibiotics that interfere with DNA and protein synthesis, including tetracyclines, macrolides and quinolones, which are the compounds that have been most extensively studied and used for treatment of human infection. Since our original review was published in 2011, there have been some major advances in diagnostic tests for C. trachomatis and the introduction of the first FDA-approved test for the detection of C. pneumoniae in respiratory samples. However, the options for treating chlamydial infections have largely remained the same. There are a small number of new drugs currently in preclinical development and early clinical trials that may have a role in the treatment of chlamydial infections.

Recent advances in understanding and managing Chlamydia trachomatis infections

Worldwide, Chlamydia trachomatis infections rank among the most common sexually transmitted infections (STI), and cause notable reproductive morbidity in women. Although advances in highly accurate and non-invasive diagnostic testing have allowed for better estimation of the burden of disease—especially the asymptomatic state—we still lack a true point-of-care test, and many infections go undetected and untreated. Moreover, limited resources and effort for managing sexual partners of those in whom infection is actually identified comprise a major challenge to control. Here, we review the current state of understanding of this common infection, and efforts to control it.