Colonisation of the male reproductive tract in asymptomatic infertile men: Effects on semen quality

An overview regarding the relationship between Mollicutes, infertility and antibiotic resistance (Review)

Throughout the past decades, physicians have increasingly conferred regarding the role of Mollicutes in infertility in both male and female patients. Although Ureaplasma and Mycoplasma do not represent a leading cause of infertility, whether dermatovenerologists, gynecologists and urologists should not disregard them when screening patients with infertility problems is discussed in the present review. While these infections are completely asymptomatic in ~80% of cases, they do lead to both chronic inflammation of the genital tract and reproductive disorders. Different Mollicute strains and/or serovars, genomic traits and proteomic markers have been examined in order to understand not only the exact mechanism by which they cause infertility, but also their relationship with the worldwide spreading resistance to antibiotics. The current review provided an overview of the latest studies regarding the new findings on the relationship between Mollicutes, infertility and antibiotic resistance. Awareness should be raised among clinicians to screen sexually active adults wishing to conceive who have failed to achieve a pregnancy; in addition, an antibiogram should be performed and treatment should be carried out according to the guidelines.

The elusive male microbiome: revealing the link between the genital microbiota and fertility. Critical review and future perspectives

There is a growing focus on understanding the role of the male microbiome in fertility issues. Although research on the bacterial communities within the male reproductive system is in its initial phases, recent discoveries highlight notable variations in the microbiome's composition and abundance across distinct anatomical regions like the skin, foreskin, urethra, and coronary sulcus. To assess the relationship between male genitourinary microbiome and reproduction, we queried various databases, including MEDLINE (available via PubMed), SCOPUS, and Web of Science to obtain evidence-based data. The literature search was conducted using the following terms "gut/intestines microbiome," "genitourinary system microbiome," "microbiome and female/male infertility," "external genital tract microbiome," "internal genital tract microbiome," and "semen microbiome." Fifty-one relevant papers were analyzed, and eleven were strictly semen quality or male fertility related. The male microbiome, especially in the accessory glands like the prostate, seminal vesicles, and bulbourethral glands, has garnered significant interest because of its potential link to male fertility and reproduction. Studies have also found differences in bacterial diversity present in the testicular tissue of normozoospermic men compared to azoospermic suggesting a possible role of bacterial dysbiosis and reproduction. Correlation between the bacterial taxa in the genital microbiota of sexual partners has also been found, and sexual activity can influence the composition of the urogenital microbiota. Exploring the microbial world within the male reproductive system and its influence on fertility opens doors to developing ways to prevent, diagnose, and treat infertility. The present work emphasizes the importance of using consistent methods, conducting long-term studies, and deepening our understanding of how the reproductive tract microbiome works. This helps make research comparable, pinpoint potential interventions, and smoothly apply microbiome insights to real-world clinical practices.

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.

Risk Prediction of Ureaplasma urealyticum Affecting Sperm Quality Based on Mathematical Model and Cross-Sectional Study

Objective. To explore the risk of Ureaplasma urealyticum (UU) affecting sperm quality. Methods. Prospective cross-sectional study was conducted. In total, 340 semen samples were collected. According to whether they were infected with UU, the samples were divided into the UU-positive group (observation group) and UU-negative group (control group). The patients with UU-positive were followed up to obtain treatment and collected the semen again after treatment. The semen characteristics and sperm parameters were detected and compared, and the relationship of UU and the sperm quality was analyzed by mathematical models. Results. There were 104 UU-positive semen samples in all, with an overall infection rate of 30.6%, which was highest in 31 to 40-year-old men, and over 40-year-old men were the lowest. The pH, PR, VCL, VSL, and STR in the observation group were significantly lower than those in the control group (all $P<0.001$ ), while SV, NP, and WOB were significantly higher (all $P<0.001$ ). After treatment, the pH, VSL, LIN, WOB, and STR in the observation group were significantly higher than before (all $P<0.001$ ), while SV and VCL were significantly lower (all $P<0.001$ ). UU infection was closely correlated with pH, PR, NP, VCL, VSL, WOB, and STR. During the treatment, pH, PR, VSL, WOB, and STR increased, but NP and VCL decreased. 7 major factors that would affect SQ were extracted, of which VAP, LIN, and UU were the first three main factors. The risk of SQ declining after UU infection increased nearly twice with the change of PR and VCL and increased 0.08 times with STR. Conclusion. UU may approximately double the risk of altering the sperm’s curvilinear movement rate and straightness to affect the sperm quality.