Improvement of semen parameters after antibiotic therapy in asymptomatic infertile men infected with Mycoplasma genitalium

Semen Microbiome, Male Infertility, and Reproductive Health

The semen microbiome, once believed to be sterile, is now recognized as a dynamic ecosystem containing a diverse range of microorganisms with potential implications for male fertility and reproductive health. We aimed to examine the relationship between the semen microbiome, male infertility, and reproductive outcomes, highlighting the transformative role of next generation sequencing techniques and bioinformatics in exploring this intricate interaction, and we present a critical review of the published literature on this issue. Current evidence suggests a complex association between the composition of the semen microbiome and male fertility, with certain bacterial genera, such as Lactobacillus and Prevotella that exert opposing effects on sperm quality and DNA integrity. In addition, the influence of the semen microbiome extends beyond natural fertility, affecting assisted reproductive technologies and pregnancy outcomes. Despite considerable progress, challenges remain in standardizing methodologies and interpreting findings. In conclusion, we identify the lack of a definitive management proposal for couples presenting with this phenomenon, and we underline the need for an algorithm and indicate the questions raised that point toward our goal for a strategy. Continued research is essential to clarify the role of the semen microbiome in male reproductive health and to advance the development of personalized fertility management approaches.

The possible pathogenic mechanisms of microorganisms in infertility: a narrative review

Infertility can harm a patient in physical, psychological, spiritual, and medical ways. This illness is unusual because it affects the patient's companion and the patient individually. Infertility is a multifactorial disease, and various etiological factors like infection are known to develop this disorder. Recently published studies reported that different bacteria, such as Chlamydia trachomatis, Mycoplasma spp., Ureaplasma urealyticum, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, can lead to infertility by immunopathological effects, oxidative stress, and adverse effects on sperm concentration, motility, morphology, and DNA condensation. Among viruses, Human papillomavirus and Herpes simplex virus reduce sperm progressive motility and sperm concentration. The viruses can lead to the atrophy of the germinal epithelium and degenerative changes in the testes. Candida albicans also harm sperm quality, motility, and chromatin integrity and induce apoptosis in sperm cells. Finally, Trichomonas vaginalis leads to distorted heads, broken necks, and acrosomes exocytosis in sperms. This parasite decreases sperm viability and functional integrity. Noteworthy, oxidative stress could have a role in many pathological changes in the reproductive system. Recent findings show that microorganisms can increase reactive oxygen species concentration inside the host cells, leading to oxidative stress and sperm distress and dysfunction. Therefore, this article explores the potential significance of critical bacteria linked to infertility and their pathogenic mechanisms that can affect sperm function and the female reproductive system.

Pharmacological therapies for male infertility

Male factor infertility is a multifaceted problem that affects approximately 50% of couples suffering from infertility. Causes of male infertility include endocrine disturbances, gonadotoxins, genetic abnormalities, varicocele, malignancies, infections, congenital or acquired urogenital abnormalities, iatrogenic factors, immunological factors, and idiopathic reasons. There are a variety of treatment options for male infertility, depending on the underlying cause(s). These can include surgical treatments, medical/hormonal therapies, and assisted reproductive techniques (ART), which can be combined with surgical sperm retrieval (SSR) if necessary. In this review article, the pharmacological therapies for male infertility are grouped by their underlying causes. Some of these therapies are targeted and specific, while others are used empirically to treat idiopathic male infertility. This will include treatments to optimize infertility in patients who have hypogonadism, ejaculatory dysfunction, infections, or idiopathic male infertility. Finally, we will provide an overview of the future directions of pharmacological therapies for male infertility. Significance Statement Male infertility is a significant worldwide problem. Detailed knowledge of the pharmacological therapies available will ensure the prescription of appropriate therapy and avoid the use of unnecessary or harmful treatments.

[First-line management of infertile couple. Guidelines for clinical practice of the French College of Obstetricians and Gynecologists 2022]

OBJECTIVE

To update the 2010 CNGOF clinical practice guidelines for the first-line management of infertile couples.

MATERIALS AND METHODS

Five major themes (first-line assessment of the infertile woman, first-line assessment of the infertile man, prevention of exposure to environmental factors, initial management using ovulation induction regimens, first-line reproductive surgery) were identified, enabling 28 questions to be formulated using the Patients, Intervention, Comparison, Outcome (PICO) format. Each question was addressed by a working group that had carried out a systematic review of the literature since 2010, and followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) methodology to assess the quality of the scientific data on which the recommendations were based. These recommendations were then validated during a national review by 40 national experts.

RESULTS

The fertility work-up is recommended to be prescribed according to the woman's age: after one year of infertility before the age of 35 and after 6months after the age of 35. A couple's initial infertility work-up includes a single 3D ultrasound scan with antral follicle count, assessment of tubal permeability by hysterography or HyFOSy, anti-Mullerian hormone assay prior to assisted reproduction, and vaginal swabbing for vaginosis. If the 3D ultrasound is normal, hysterosonography and diagnostic hysteroscopy are not recommended as first-line procedures. Chlamydia trachomatis serology does not have the necessary performance to predict tubal patency. Post-coital testing is no longer recommended. In men, spermogram, spermocytogram and spermoculture are recommended as first-line tests. If the spermogram is normal, it is not recommended to check the spermogram. If the spermogram is abnormal, an examination by an andrologist, an ultrasound scan of the testicles and hormonal test are recommended. Based on the data in the literature, we are unable to recommend a BMI threshold for women that would contraindicate medical management of infertility. A well-balanced Mediterranean-style diet, physical activity and the cessation of smoking and cannabis are recommended for infertile couples. For fertility concern, it is recommended to limit alcohol consumption to less than 5 glasses a week. If the infertility work-up reveals no abnormalities, ovulation induction is not recommended for normo-ovulatory women. If intrauterine insemination is indicated based on an abnormal infertility work-up, gonadotropin stimulation and ovulation monitoring are recommended to avoid multiple pregnancies. If the infertility work-up reveals no abnormality, laparoscopy is probably recommended before the age of 30 to increase natural pregnancy rates. In the case of hydrosalpinx, surgical management is recommended prior to ART, with either salpingotomy or salpingectomy depending on the tubal score. It is recommended to operate on polyps>10mm, myomas 0, 1, 2 and synechiae prior to ART. The data in the literature do not allow us to systematically recommend asymptomatic uterine septa and isthmoceles as first-line surgery.

CONCLUSION

Based on strong agreement between experts, we have been able to formulate updated recommendations in 28 areas concerning the initial management of infertile couples.

Genital mycoplasma infection: a systematic review and meta-analysis

BACKGROUND

Recent studies have suggested that genital mycoplasma infections may be associated with male infertility. However, this association remains controversial due to time lapse, sample size, and regional prevalence.

OBJECTIVES

This study aimed to systematically evaluate the relationship between genital mycoplasma and male infertility through a meta-analysis and to provide a basis for the clinical management of male infertility.

METHODS

We conducted a search on PubMed, EMBASE, the Cochrane Library, and CNKI databases, from January 2000 to June 2023 to identify case-control studies on the interrelationship between genital mycoplasma infection and male infertility. Two independent researchers performed an assessment of the methodological quality of trials according to the Newcastle-Ottawa scale and extracted data strictly based on the inclusion and exclusion criteria, and afterward, we carried out a meta-analysis using Stata 16.0. Pooled odds ratios (OR) with 95% confidence intervals (CI) were used to assess this relationship.

RESULTS

This meta-analysis included 21 studies from seven countries with a total of 53025 infertility cases and 6435 controls; the age range of the participating men was from 20 to 59 years old. The results obtained showed a higher prevalence of M. genitalium, M. hominis and U. urealyticum infections in infertile men than in the controls, with the opposite result for U. parvum (M. genitalium, OR, 3.438 [95% CI: 1.780, 6.643], with P = 0.000; M. hominis, OR, 1.840 [95% CI: 1.013, 3.343], with P = 0.045; U. urealyticum, OR, 3.278 [95% CI: 2.075, 5.180], with P = 0.000; U. parvum, OR, 1.671 [95% CI: 0.947, 2.950], with P = 0.077). Further, two subgroup analyses also showed that M. hominis and U. urealyticum infections were strongly associated with male infertility in China (M. hominis, P = 0.009; U. urealyticum, P = 0.000); however, M. hominis and U. urealyticum infection was not strongly associated with male infertility worldwide (M. hominis, P = 0.553; U. urealyticum, P = 0.050).

CONCLUSION

This meta-analysis revealed that male infertility was significantly associated with M. genitalium, M. hominis and U. urealyticum infections, while U. parvum infection was not. Further, our study showed that genital mycoplasma infection influences male infertility and provides a basis for future treatment.

Semen dysbiosis—just a male problem?

Seminal microflora is crucial to male fertility. Dysbiosis—disturbance of quantitative ratios of individual bacteria or appearance of pathogenic species—rarely results in symptomatic disease. Inflammation results in decreased sperm production, lower motility, or morphological changes and, in the long term, can cause ejaculatory duct obstruction, leading to infertility. Moreover, it may cause infection of the partner’s female genital tract. Dysbiosis in both partners results in fertility problems, disorders in embryo implantation, or miscarriages. In addition, chronic inflammation of the male genitourinary system may accelerate the appearance of antisperm antibodies. A comprehensive examination of seminal microflora can clarify the causes of infertility or prevent pathological conditions that affect seminal parameters. Seminal microflora as a direct impact on fertility problems as well as a decrease in the effectiveness of assisted reproduction methods, insemination, or in vitro procedures.

Ureaplasma urealyticum induces polymorphonuclear elastase to change semen properties and reduce sperm motility: a prospective observational study

Objective

To elucidate the mechanism underlying how Ureaplasma urealyticum (UU) affects sperm quality and identify a therapeutic target.

Methods

In this prospective observational study, the differences in and relationships among semen volume, pH, viscosity, liquefaction time, sperm concentration, sperm motility [progressive motility (PR)], and seminal polymorphonuclear (PMN) elastase were analyzed in 198 normal semen samples (control group) and 198 UU-infected semen samples (observation group). The UU-infected samples were treated and the above parameters were compared between the two groups.

Results

The semen volume, viscosity, liquefaction time, and seminal PMN elastase were significantly higher in the observation than control group, but the pH and PR were significantly lower. In the observation group, the pH and PR were significantly higher after than before treatment, whereas the semen volume, PMN elastase, viscosity, and liquefaction time were lower. UU was closely related to semen volume, pH, viscosity, liquefaction time, sperm motility (PR), and PMN elastase. PMN elastase had significant negative effects on semen pH and sperm motility (PR) but positive effects on viscosity and liquefaction time.

Conclusion

UU might induce PMN elastase to increase the liquefaction time and viscosity of semen, eventually decreasing PR. PMN elastase might be a therapeutic target of UU.

Evaluation of the Presence of Bacterial and Viral Agents in the Semen of Infertile Men: A Systematic and Meta-Analysis Review Study

Objectives

Infections in the male genitourinary system with bacterial and viral agents may play a significant role in male infertility. These agents usually infect the urethra, seminal vesicles, prostate, epididymis, vas deferens, and testes retrograde through the reproductive system. A meta-analysis review study was performed to evaluate the presence of bacterial and viral agents in the semen of infertile men and its correlation with infertility.

Methods

Relevant cross-sectional and/or case-control studies were found by an online review of national and international databases (Web of Science, PubMed, Scopus, Science Direct, and Google scholar), and suitable studies were selected. A checklist determined the qualities of all studies. Heterogeneity assay among the primary studies was evaluated by Cochran’s Q test and I² index (significance level 50%). A statistical analysis was conducted using the Comprehensive Stata ver. 14 package (StataCorp, College Station, TX, United States).

Results

Seventy-two studies were included in this meta-analysis. Publication bias was compared with Egger’s test, and the impact of each research on overall estimate was evaluated by sensitivity analysis. In 56 studies, the rate of bacterial infections in the semen of infertile men was 12% [95% confidence interval (CI): 10–13]. Also, in 26 case-control studies, the association of infertility in men with bacterial infections was evaluated. The results show that the odds ratio of infertility in men exposed to bacterial infections is 3.31 times higher than that in non-infected men (95% CI: 2.60–4.23). Besides, in 9 studies that examined the prevalence of human papillomavirus (HPV), herpes simplex virus 1 (HSV1), herpes simplex virus 2 (HSV2), and herpes simplex virus 1-2 (HSV1-2) in infertile men, the frequency of these viruses was 15% (95% CI: 9–21). In 6 case-control studies, the association between human cytomegalovirus (HCMV), Cytomegalovirus (CMV), and HPV and male infertility was evaluated. The chance of male infertility due to exposure to these viruses was 2.24 times higher than those without exposure to these viruses (CI 95%: 1.9–4.52). The results show that the chance of infertility in men exposed to bacteria was significantly higher than that in the uninfected population.

Conclusion

This meta-analysis showed that viral and bacterial infections are a risk factor and could impair male fertility potential. Moreover, our study supports the hypothesis that bacterial and viral infections of the genital tract correlate positively with impairment of sperm quality in the male population.

Microbiome Compositions From Infertile Couples Seeking In Vitro Fertilization, Using 16S rRNA Gene Sequencing Methods: Any Correlation to Clinical Outcomes?

Background

Bacterial infections are usually suspected in infertile couples seeking IVF with no clear understanding of the microbial compositions present in the seminal fluids and vaginal niche of the patients. We used next-generation sequencing technology to correlate microbiota compositions with IVF clinical outcomes.

Methods

Thirty-six couples were recruited to provide seminal fluids and vaginal swabs. Bacterial DNA was extracted, and V4 region of the 16S rRNA was amplified and sequenced in a pair-end configuration on the Illumina MiSeq platform rendering 2 × 150 bp sequences. Microbial taxonomy to species level was generated using the Greengenes database. Linear discriminant analysis (LDA) effect size (LEfSe) was used to identify biologically and statistically significant differences in relative abundance.

Results

Seminal fluid microbiota compositions had lower bacterial concentrations compared with the vagina, but species diversity was significantly higher in seminal fluid samples. Azoospermic subjects had more relative abundance of Mycoplasma and Ureaplasma. In Normospermic semen, Lactobacillus (43.86%) was the most abundant, followed by Gardnerella (25.45%), while the corresponding vaginal samples, Lactobacillus (61.74%) was the most abundant, followed by Prevotella (6.07%) and Gardnerella (5.86%).

Conclusions

Semen samples with positive IVF were significantly colonized by Lactobacillus jensenii (P=0.002), Faecalibacterium (P=0.042) and significantly less colonized by Proteobacteria, Prevotella, Bacteroides, and lower Firmicutes/Bacteroidetes ratio compared with semen samples with negative IVF. Vaginal samples with positive IVF clinical outcome were significantly colonized by Lactobacillus gasseri, less colonized by Bacteroides and Lactobacillus iners. This study has opened a window of possibility for Lactobacillus replenishments in men and women before IVF treatment.

Effect of bacterial infection on sperm quality and DNA fragmentation in subfertile men with Leukocytospermia

Background

Although bacterial infections have been recognized as a possible cause of male infertility, the effect of bacterial infections on sperm quality and sperm DNA fragmentation remains controversial. The current study aimed to investigate the prevalence rate of bacterial infection in subfertile men and its effect on semen quality. Seminal fluid was collected from 172 male members of infertile couples attending the andrology infertility center and a group of 35 fertile subjects as a control. Sperm parameters and DNA fragmentation were evaluated based on the type of bacteria in all ejaculates.

Results

From the 172 patients investigated for infertility, 60 (34.88%) patients had a positive culture for pathogenic bacteria of different species. Leukocytospermia was significantly higher in infected samples in comparison with non-infected samples (p < 0.05). Sperm concentration and motility and morphology were significantly lower in infected than non-infected samples. Moreover, sperm DNA fragmentation was significantly higher in infected than non-infected samples. Besides, our results showed that sperm DNA fragmentation was correlated significantly with leukocytospermia (R: 0.22, p < 0.01).

Conclusion

The present study suggested that bacterial infection significantly correlated with leukocytospermia could impair male fertility potential through decreasing sperm motility, morphology, and DNA integrity.

Segesterone acetate serum levels with a regression model of continuous use of the segesterone acetate/ethinyl estradiol contraceptive vaginal system

OBJECTIVE

To predict serum segesterone (SA) and ethinyl estradiol (EE) levels after 364 days of hypothetical continuous use (without removal) of a cyclic contraceptive vaginal system (CVS) containing 0.15 mg SA and 0.013 mg EE.

STUDY DESIGN

We used pharmacokinetic (PK) data (n = 37) from a multicenter, open-label, nonrandomized study of healthy women (18-38 years) that used the CVS for 13 cycles in a 21 days-in/7 days-out regimen to develop a linear regression model to predict daily serum SA and EE levels for 364 days of continuous CVS use. We then determined residual SA/EE levels in vitro from 18 randomly chosen CVS used by women who completed 13 cycles. Serum SA and EE levels were also predicted for 364 days of continuous CVS use in another in vitro study.

RESULTS

After a hypothetical 364 days of continuous CVS use, we predicted daily mean serum levels to be 184 pmol/L (95% confidence interval [CI], 102‒332 pmol/L) for SA and 43 pmol/L (95% CI, 19‒95 pmol/L) for EE. We did predict that serum EE levels would not accumulate over time. Residual SA and EE in the CVS were 60% and 80% of the original load after 13 cycles, respectively.

CONCLUSION

The predicted serum SA level after 364 days of hypothetical continuous CVS use was comparable to reported levels at which no pregnancy occurred (>100 pmol/L), showing the potential of the CVS for one year of continuous use. Clinical trials on continuous CVS use are planned.

IMPLICATIONS

Based on statistical modeling, the long-term, user-controlled contraceptive vaginal system containing segesterone acetate and ethinyl estradiol may have the potential to provide effective pregnancy prevention if used continuously (without removal) for one year. Further investigation is warranted.

Mycoplasma genitalium: A Review

Mycoplasma genitalium is a fastidious organism of the class Mollicutes, the smallest prokaryote capable of independent replication. First isolated in 1981, much is still unknown regarding its natural history in untreated infection. It is recognized as a sexually transmitted pathogen causing acute and chronic non-gonococcal urethritis (NGU) in men, with a growing body of evidence to suggest it also causes cervicitis and pelvic inflammatory disease in women. Its role in several other clinical syndromes is uncertain. The majority of people infected remain asymptomatic and clear infection without developing disease; asymptomatic screening is therefore not recommended. Prevalence rates are higher in patients attending sexual health clinics and in men with NGU. Limited availability of diagnostics has encouraged syndromic management, resulting in widespread antimicrobial resistance and given that few antimicrobial classes have activity against M. genitalium, there is significant concern regarding the emergence of untreatable strains. There is a need for wider availability of testing, which should include detection of macrolide resistance mediating mutations. Expertise in interpretation of microbiological results with clinical correlation ensures targeted treatment avoiding unnecessary antibiotic exposure. Public health surveillance nationally and internationally is vital in monitoring and responding to changing epidemiology trends. In this review, we summarize current knowledge of M. genitalium, including epidemiology, clinical and microbiological data, and discuss treatment challenges in the era of rising multidrug resistance.

Leukocytospermia is not an informative predictor of positive semen culture in infertile men: results from a validation study of available guidelines

STUDY QUESTION

Are the European Association of Urology (EAU) guidelines for performing semen culture accurate enough for detecting a positive semen culture in Caucasian-European infertile men?

SUMMARY ANSWER

The majority (80%) of asymptomatic infertile men with a positive sperm culture may miss a proper diagnostic assessment when relying on EAU guidelines; no single parameter can assist in medical decision-making.

WHAT IS KNOWN ALREADY

The EAU guidelines suggest performing semen culture in case of increased leukocytes in semen (>106 peroxidase positive white blood cells/ml, i.e. leukocytospermia).

STUDY DESIGN SIZE DURATION

A cross-sectional validation study including 523 infertile men was carried out during 2010-2018.

PARTICIPANTS/MATERIALS SETTING METHODS

Infertile men who were asymptomatic for genital infections were enrolled at a single academic center, and a semen culture was obtained in every case. A concentration of >103 cfu/ml urinary tract pathogens in the ejaculate was considered indicative of significant bacteriospermia. Semen analysis values were assessed on the basis of 2010 World Health Organization reference criteria. EAU guidelines for semen culture were used to predict positive semen culture in our cohort and thus validated. Moreover, we tested the predictive performance and accuracy of several clinical parameters and compared them to EAU guidelines.

MAIN RESULTS AND THE ROLE OF CHANCE

A positive semen culture was found in 54 men (10%). The application of EAU guidelines would have missed 43 out of 54 (80%) positive semen cultures with 120/131 (92%) useless examinations. EAU guidelines specificity, sensitivity and discrimination were 74%, 20% and 47%, respectively. When trying to improve positive semen culture prediction, we were unable to find any informative baseline parameter except for serum neutrophil-to-lymphocyte ratio (odds ratio 1.70 (95% CI 1.04-2.77)), although without any improvement in terms of discrimination (P = 0.10).

LIMITATIONS REASONS FOR CAUTION

The study was limited by the lack of a control group of fertile men its retrospective nature. Moreover, monoclonal antibodies were not used for leukocyte assessment.

WIDER IMPLICATIONS OF THE FINDINGS

Since it is not possible to identify infertile men at risk of semen infection, further studies are needed to tailor the execution of semen culture.

STUDY FUNDING/COMPETING INTERESTS

No funding was received for this study. There are no competing interests.

Potential Pathogenic Bacteria in Seminal Microbiota of Patients with Different Types of Dysspermatism

Human microbiota play an important role in the health of their human hosts. Recent studies have demonstrated that microbiota exist in seminal plasma. The current study aims to elucidate whether seminal microbiota exist in patients with different types of dysspermatism and whether bacterial biomarkers can be identified for them. A total of 159 study participants were recruited, including 22 patients with oligoasthenospermia, 58 patients with asthenospermia, 8 patients with azoospermia, 13 patients with oligospermia, and 58 matched healthy controls. Seminal microbiota composition was analyzed using 16S rRNA gene-based sequencing. The results showed that the composition of seminal microbiota of patients with dysspermatism differed from those of healthy controls. Comparison of the microbiota composition in semen samples from patients with different types of dysspermatism showed that microbiota in patients with asthenospermia and oligoasthenospermia were distinct from healthy controls in beta diversity (P < 0.05). Characteristic biomarkers, including Ureaplasma, Bacteroides, Anaerococcus, Finegoldia, Lactobacillus and Acinetobacter lwoffii, were identified based on LEfSe analysis. Inferred functional analysis based on seminal microbiome data further indicated the presence of potential pathogenic biomarkers in patients with asthenospermia and oligoasthenospermia. These results provided profiles of seminal microbiota exhibited in different types of dysspermatism, thus providing new insights into their pathogenesis.