Evaluation of treatment with two weeks of doxycycline on macrolide-resistant strains of Mycoplasma genitalium: a retrospective observational study

Sexually Transmitted Infections in the Emergency Department

As the United States faces a worsening epidemic of sexually transmitted infections (STIs), emergency departments (EDs) play a critical role in identifying and treating these infections. The growing health inequities in the distribution and disproportionate impact of STIs add to the urgency of providing high-quality sexual health care through the ED. Changes in population health are reflected in the new Centers for Disease Control recommendations on screening, diagnostic testing, and treatment of STIs. This review covers common, as well as and less common or emerging STIs, and discusses the state-of-the-art guidance on testing paradigms, extragenital sampling, and antimicrobial treatment and prevention of STIs.

Treatment of Mycoplasma genitalium infection in pregnancy: A systematic review of international guidelines

BACKGROUND

Mycoplasma genitalium is an emerging pathogen, which has been linked to cervicitis, urethritis and pelvic inflammatory disease (PID). With the advent of multiplex polymerase chain reaction (PCR) panels for sexually transmitted infections, it is increasingly being identified in pregnant women.

OBJECTIVES

The aim was to review international guidelines, which had explicit recommendations for treatment of M. genitalium infection in pregnancy and breastfeeding.

SEARCH STRATEGY

PubMed, EMBASE and Cochrane databases were reviewed with no age, species, language or date restrictions.

SELECTION CRITERIA

Studies were included if they had an explicit recommendation for treatment of M. genitalium in pregnancy. Studies were excluded if there was no recommendation in pregnancy, if they referred to other international guideline recommendations or were historical versions of guidelines.

DATA COLLECTION AND ANALYSIS

References were manually reviewed and 50 papers were selected for review. Only four guidelines were included in the final analysis and they were from Europe, UK, Australia and Aotearoa New Zealand.

MAIN RESULTS

All studies recommended azithromycin as first-line treatment, and advised against moxifloxacin use. The dosing schedule of azithromycin, varied between guidelines, as did the utility/safety of pristinamycin for macrolide resistant infections. Safety data was generally reassuring for azithromycin but inconsistent for pristinamycin.

CONCLUSIONS

Azithromycin is the first-line treatment for macrolide susceptible or unknown resistance infections, but there is a lack of consistency regarding dosing of azithromycin or the utility/safety of pristinamycin for macrolide resistant infections in pregnancy/lactation.

Treatment of bacterial sexually transmitted infections in Europe: gonorrhoea, Mycoplasma genitalium, and syphilis

This review explores the therapeutic challenges of sexually transmitted infections (STI) in Europe, which include increasing antimicrobial resistance and limited progress in drug discovery. We primarily focus on gonorrhoea, Mycoplasma genitalium, and syphilis infections. For gonorrhoea with escalating resistance rates we explore the possibility of combining ceftriaxone with another antibiotic or using alternative antibiotics to mitigate resistance emergence, and we provide insights on the ongoing evaluation of new antimicrobials, like gepotidacin and zoliflodacin. In the case of M. genitalium, which exhibits high resistance rates to first and second-line treatments, we emphasize the importance of resistance-guided therapy in regions with elevated resistance levels, and highlight the limited alternative options, such as pristinamycin and minocycline. Furthermore, we address the challenges posed by syphilis, where the primary treatment consists of penicillin or doxycycline, with challenges arising in neurosyphilis, allergy, pregnancy, and supply shortages and discuss the ongoing evaluation of alternative antimicrobials (e.g., ceftriaxone, cefixime, linezolid). Our findings identify priority actions and provide concrete solutions for long-term effective management of STIs and antimicrobial resistance mitigation.

Update in Epidemiology and Management of Mycoplasma genitalium Infections

Mycoplasma genitalium is a frequent cause of urogenital syndromes in men and women and is associated with adverse sequelae in women. M genitalium also infects the rectum, and may cause proctitis, but rarely infects the pharynx. Diagnosis requires nucleic acid amplification testing. Antibiotic resistance is widespread: more than half of infections are resistant to macrolides and fluoroquinolone resistance is increasing. Resistance-guided therapy is recommended for symptomatic patients, involving initial treatment with doxycycline to reduce organism load followed by azithromycin for macrolide-sensitive infections or moxifloxacin for macrolide-resistant infections. Neither screening nor tests of cure are recommended in asymptomatic persons.

Defensins: defenders of human reproductive health

BACKGROUND

Reproductive tract infection is an important factor leading to male and female infertility. Among female infertility factors, microbial and viral infections are the main factors affecting female reproductive health and causing tubal infertility, ectopic tubal pregnancy and premature delivery. Among male infertility factors, 13-15% of male infertility is related to infection. Defensins are cationic antibacterial and antiviral peptides, classified into α-defensins, β-defensins and θ-defensins. Humans only have α-defensins and β-defensins. Apart from their direct antimicrobial functions, defensins have an immunomodulatory function and are involved in many physiological processes. Studies have shown that defensins are widely distributed in the female reproductive tract (FRT) and male reproductive tract (MRT), playing a dual role of host defence and fertility protection. However, to our knowledge, the distribution, regulation and function of defensins in the reproductive tract and their relation to reproduction have not been reviewed.

OBJECTIVE AND RATIONALE

This review summarizes the expression, distribution and regulation of defensins in the reproductive tracts to reveal the updated research on the dual role of defensins in host defence and the protection of fertility.

SEARCH METHODS

A systematic search was conducted in PubMed using the related keywords through April 2022. Related data from original researches and reviews were integrated to comprehensively review the current findings and understanding of defensins in the human reproductive system. Meanwhile, female and male transcriptome data in the GEO database were screened to analyze defensins in the human reproductive tracts.

OUTCOMES

Two transcriptome databases from the GEO database (GSE7307 and GSE150852) combined with existing researches reveal the expression levels and role of the defensins in the reproductive tracts. In the FRT, a high expression level of α-defensin is found, and the expression levels of defensins in the vulva and vagina are higher than those in other organs. The expression of defensins in the endometrium varies with menstrual cycle stages and with microbial invasion. Defensins also participate in the local immune response to regulate the risk of spontaneous preterm birth. In the MRT, a high expression level of β-defensins is also found. It is mainly highly expressed in the epididymal caput and corpus, indicating that defensins play an important role in sperm maturation. The expression of defensins in the MRT varies with androgen levels, age and the status of microbial invasion. They protect the male reproductive system from bacterial infections by neutralizing lipopolysaccharide and downregulating pro-inflammatory cytokines. In addition, animal and clinical studies have shown that defensins play an important role in sperm maturation, motility and fertilization.

WIDER IMPLICATIONS

As a broad-spectrum antimicrobial peptide without drug resistance, defensin has great potential for developing new natural antimicrobial treatments for reproductive tract infections. However, increasing evidence has shown that defensins can not only inhibit microbial invasion but can also promote the invasion and adhesion of some microorganisms in certain biological environments, such as human immunodeficiency virus. Therefore, the safety of defensins as reproductive tract anti-infective drugs needs more in-depth research. In addition, the modulatory role of defensins in fertility requires more in-depth research since the current conclusions are based on small-size samples. At present, scientists have made many attempts at the clinical transformation of defensins. However, defensins have problems such as poor stability, low bioavailability and difficulties in their synthesis. Therefore, the production of safe, effective and low-cost drugs remains a challenge.

Weighing Potential Benefits and Harms of Mycoplasma genitalium Testing and Treatment Approaches

This systematic review demonstrates increasing antimicrobial resistance and incomplete understanding of the bacterium’s natural history.

Since Mycoplasma genitalium was identified 40 years ago, much of the epidemiology has been described, diagnostic tests have been developed and approved, and recommended treatment approaches have been identified. However, the natural history remains incompletely understood, and antimicrobial resistance has rapidly increased. This review summarizes evidence published since the US Centers for Disease Control and Prevention 2015 Sexually Transmitted Diseases Treatment Guidelines. Data on sequelae remain insufficient, macrolide resistance is common, and fluoroquinolone resistance is increasing. Potential benefits of testing and treatment include resolving symptoms, interrupting transmission, and preventing sequelae. Potential harms include cost, patient anxiety, and increasing antimicrobial resistance.

Retrospective Analysis of Ugandan Men with Urethritis Reveals Mycoplasma genitalium and Associated Macrolide Resistance

The rising rates of antimicrobial resistance (AMR) in Mycoplasma genitalium globally and the association of this sexually transmitted infection (STI) with cervicitis, urethritis, and HIV are potentially of great public health concern. Data on the epidemiology of M. genitalium in men in sub-Saharan Africa are limited. We sought to determine the prevalence of M. genitalium and macrolide resistance in men with urethritis in Kampala, Uganda. Self-collected penile-meatal swabs and/or urine samples from men with symptomatic urethritis (n = 250) were retrospectively analyzed for the presence of M. genitalium and macrolide resistance markers with the Aptima M. genitalium and ResistancePlus M. genitalium assays. Additionally, demographic and STI coinfection data were used to investigate associations with M. genitalium infection. M. genitalium was detected in 12.8% (32/250) of individuals; 40.6% (n = 13) had M. genitalium monoinfection. Mutations associated with macrolide resistance were detected in 10.7% (3/28) of participants. Coinfection with Neisseria gonorrhoeae was common (41.0%), but M. genitalium was more prevalent in participants without N. gonorrhoeae coinfection (P = 0.001). M. genitalium is common in Ugandan men with urethritis both as a monoinfection and as a coinfection with other curable STIs. Macrolide resistance was present and warrants further research on treatment outcomes and the association between untreated M. genitalium and subsequent morbidity. IMPORTANCE Mycoplasma genitalium is a common sexually transmitted infection associated with urethritis in men. Little is known about M. genitalium infection in men with urethritis in Uganda. We report that 12% of participants in this study were positive for M. genitalium and that resistance to azithromycin, a macrolide antibiotic, is present. Furthermore, we show that either self-collected penile-meatal swabs or urine can be used for detection of M. genitalium.

Impact of 16S rRNA Single Nucleotide Polymorphisms on Mycoplasma genitalium Organism Load with Doxycycline Treatment

Doxycycline targets the 16S rRNA and is widely used for the treatment of sexually transmitted infections. While it is not highly effective at eradicating Mycoplasma genitalium infections, it can reduce organism load. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the 16S rRNA gene of M. genitalium and change in organism load. M. genitalium samples were collected from 56 men prior to commencing doxycycline and at a median of 13 of 14 doses. These were sequenced for the 16S rRNA, and the association between 16S rRNA SNPs and change in organism load was determined. 16S rRNA sequences were available for 52/56 (92.9%) M. genitalium-infected men, of which 20 (38.5%) had an undetectable load, 26 (50.0%) had a decrease in M. genitalium load (median change of 105-fold), and 6 (11.5%) had an increase in load (median change of 5-fold). The most common SNPs identified were A742G (10/52 [19.2%]), GG960-961TT/C (7/52 [13.5%]), and C1435T (28/52 [53.8%]) (M. genitalium numbering). None were associated with a change in organism load (P = 0.76, 0.16, and 0.98, respectively). Using pooled published data from 28 isolates, no clear relationship between the SNPs and doxycycline MIC was identified. In conclusion, the low efficacy of doxycycline against M. genitalium does not appear to be due to variation in the 16S rRNA gene.