Screening for Chlamydia trachomatis and Ureaplasma urealyticum infection in semen from asymptomatic male partners of infertile couples prior to in vitro fertilization

Effect of environmental factors on seminal microbiome and impact on sperm quality

Objective

This review provides a comprehensive overview of the existing research on the seminal microbiome and its association with male infertility, while also highlighting areas that warrant further investigation.

Methods

A narrative review was conducted, encompassing all relevant studies published between 1980-2023 on the male reproductive tract microbiome in humans. This review considered studies utilizing culture-based, polymerase chain reaction (PCR)-based, and next-generation sequencing (NGS)-based methodologies to analyze the microbiome. Data extraction encompassed sample types (semen or testicular tissue), study designs, participant characteristics, employed techniques, and critical findings.

Results

We included 37 studies comprising 9,310 participants. Among these, 16 studies used culture-based methods, 16 utilized NGS, and five employed a combination of methods for microorganism identification. Notably, none of the studies assessed fungi or viruses. All NGS-based studies identified the presence of bacteria in all semen samples. Two notable characteristics of the seminal microbiome were observed: substantial variability in species composition among individuals and the formation of microbial communities with a dominant species. Studies examining the testicular microbiome revealed that the testicular compartment is not sterile. Interestingly, sexually active couples shared 56% of predominant genera, and among couples with positive cultures in both partners, 61% of them shared at least one genital pathogen. In couples with infertility of known causes, there was an overlap in bacterial composition between the seminal and vaginal microbiomes, featuring an increased prevalence of Staphylococcus and Streptococcus genera. Furthermore, the seminal microbiome had discernible effects on reproductive outcomes. However, bacteria in IVF culture media did not seem to impact pregnancy rates.

Conclusion

Existing literature underscores that various genera of bacteria colonize the male reproductive tract. These organisms do not exist independently; instead, they play a pivotal role in regulating functions and maintaining hemostasis. Future research should prioritize longitudinal and prospective studies and investigations into the influence of infertility causes and commonly prescribed medication to enhance our understanding of the seminal microbiota's role in reproductive health.

Mycoplasma genitalium Provokes Seminal Inflammation among Infertile Males

The impact of sexually transmitted infections (STI) on male fertility is controversial. Aims: To investigate the prevalence of urethritis-associated STIs (chlamydia, gonorrhoeae, Mycoplasma genitalium, trichomoniasis) among infertile males; to analyze the effect of STIs on semen parameters and blood PSA. Case-control study. Study group (n = 2000): males with fertility problems or desire for fertility check. Control group (n = 248): male partners of pregnant women. Analyses: polymerase chain reaction for STI, seminal interleukin 6 (IL-6), semen and fractionated urine, blood analyses (PSA, reproductive hormones). The prevalence of M. genitalium and chlamydia in the study group was 1.1% and 1.2%, respectively. The prevalence of chlamydia in the control group was 1.6%, while there were no M. genitalium cases. No cases with gonorrhoeae or trichomoniasis or combined infections were observed in neither group. There was a higher seminal concentration of neutrophils and IL-6 among M. genitalium positives compared with STI negatives. There was a trend toward a lower total count of spermatozoa and progressive motility among STI positives. No impact of STIs on PSA was found. The prevalence of STIs among infertile males is low. M. genitalium is associated with seminal inflammation. The impact of STIs on semen parameters deserves further investigations.

The semen microbiome and its impact on sperm function and male fertility: A systematic review and meta-analysis

BACKGROUND

Male factor is attributable in up to 50% of cases of infertility. In vitro studies demonstrate that bacteria can negatively impact sperm function. The use of next-generation sequencing techniques has provided a better understanding of the human microbiome, and dysbiosis has been reported to impact health. Evidence regarding the impact of the semen microbiome on sperm function and fertility remains conflicting.

MATERIALS AND METHODS

A systematic search was conducted in accordance with the Preferred Reporting Items for Reviews and Meta-analysis (PRISMA) statement. The databases MEDLINE, OVID and PubMed were searched to identify English language studies related to the identification of bacteria in the semen of infertile and fertile men, between 1992 and 2019. Fifty-five observational studies were included, with 51 299 subjects. We included studies identifying bacteria using next-generation sequencing, culture or polymerase chain reaction.

RESULTS

The semen microbiome was rich and diverse in both fertile and infertile men. Three NGS studies reported clustering of the seminal microbiome with a predominant species. Lactobacillus and Prevotella were dominant in respective clusters. Lactobacillus was associated with improvements in semen parameters. Prevotella appeared to exert a negative effect on sperm quality. Bacteriospermia negatively impacted sperm concentration and progressive motility, and DNA fragmentation index (DFI; MD: 3.518, 95% CI: 0.907 to 6.129, P = .008). There was an increased prevalence of ureaplasma urealyticum in infertile men (OR: 2.25, 95% CI: 1.47-3.46). Ureaplasma urealyticum negatively impacted concentration and morphology. There was no difference in the prevalence of chlamydia trachomatis between fertile and infertile men and no significant impact on semen parameters. Enterococcus faecalis negatively impacted total motility, and Mycoplasma hominis negatively impacted concentration, PM and morphology.

DISCUSSION AND CONCLUSIONS

Ureaplasma urealyticum, Enterococcus faecalis, Mycoplasma hominis and Prevotella negatively impact semen parameters, whereas Lactobacillus appears to protect sperm quality. These findings may facilitate the development of novel therapies (eg probiotics), although the evidence regarding the impact of the seminal microbiome on fertility is inconclusive and further studies are needed to investigate this association.

Prevalence of genital Chlamydia trachomatis infections in Russia: systematic literature review and multicenter study

A reliable overview of data on the prevalence of Chlamydia trachomatis (CT) in Russia is lacking and needed. All the available data on CT prevalence were analyzed in a systematic literature review on CT prevalence in Russia, strengthened with data from the multicenter study among 1263 people in the second-largest Russian megalopolis, St. Petersburg, testing for CT DNA in urethral, anal, cervical and prostate samples. A total of 10 articles met the inclusion criteria. The overall average prevalence of genital CT infections in Russian populations ranged from 2.9% to 33%. Risk factors included being symptomatic (P = 0.004; in men P < 0.001), being younger than 30 years (P = 0.001) and being a man who has sex with men (MSM) (P = 0.0084). Main limitations included the lack of studies in MSM. CT prevalence was higher in the groups where urethral and prostate secretion samples were pooled (5.2%-7.3% vs 3.2% in the urethra only). The data on CT prevalence in a range of Russian populations are analyzed and reported. Prostate secretions represent an additional sampling material for the study of CT infection in men. CT detection in some settings in St. Petersburg yielded levels of reliability comparable with internationally available tests. The initiation of screening programs for Chlamydia infections in Russia should be considered.

Screening for sexually transmitted infection pathogens in semen samples

The transmission of sexually transmitted infection (STI) pathogens from an infected donor to the recipient of a semen donation in assisted conception may result not only in acute infection but also in long-term reproductive complications or adverse outcomes of pregnancy, including infection of the offspring. Screening for bacterial STI pathogens, Chlamydia trachomatis and Neisseria gonorrhoeae is strongly recommended because these pathogens can cause serious reproductive complications in the recipients of semen donations and infection in their offspring. Screening for these pathogens should be performed using the most sensitive methods, such as nucleic acid amplified tests. False-negative results due to inhibitory substances in the semen sample should be monitored using amplification controls. Where specimen transport is not a problem and culture facilities are available, N gonorrhoeae can also be detected by culture. Laboratories performing screening should subscribe to proficiency programs and have strict quality controls. Although Trichomonas vaginalis, group B streptococcus and genital mycoplasmas have been associated with adverse outcomes of pregnancy, the frequent finding of these organisms in healthy individuals brings into question the validity of mandatory inclusion of these organisms in the screening panel. Although viral STI pathogens and Treponema pallidum - the causative agent of syphilis - may be detected in semen, their presence may be more sensitively detected through antibody testing of the donor. Screening donors for HIV, hepatitis B and syphilis by serology is uniformly recommended in all of the guidelines, but the value of screening either donors or semen samples for cytomegalovirus, herpes simplex viruses and human papilloma viruses is less clear.

[Symptomatic approach to chronic prostatitis/chronic pelvic pain syndrome]

OBJECTIVE

To review the diagnosis and pathogenesis of chronic prostatitis (CP) and chronic pelvic pain syndrome (CPPS).

MATERIAL AND METHODS

A review of the literature was performed by searching the Medline database (National Library of Medicine). Search terms were either medical subject heading (MeSH) keywords (microbiology, pelvic pain, prostatitis) or terms derived from the title or abstract. Search terms were used alone or in combinations by using the "AND" operator. The literature search was conducted from 1990 to the present time.

RESULTS

Chronic bacterial prostatitis is a chronic, recurrent bacterial infection of the prostate, accounting for about 5 to 10% of all cases of chronic prostatitis (CP). CPPS is nonbacterial genitourinary pelvic pain present for at least 3 months, sometimes associated with sexual and voiding disorders. Although the prostate does not appear to be involved in all cases of chronic pelvic pain in men, the term CP usually remains associated with CPPS (CP/CPPS). CP/CPPS has a negative impact on quality of life. The precise pathogenesis of CP/CPPS has not been elucidated, but prostatic infection and inflammation could be involved, not as direct causes, but as initiating factors of a neurological hypersensitization phenomenon. Evaluation of CP/CPPS comprises clinical interview completed by the National Institutes of Health-Chronic Prostatitis Symptom Index questionnaire (NIH-CPSI), physical examination, urine culture and uroflowmetry combined with determination of the post-voiding residual volume. The other investigations are optional and are designed to exclude other urological diagnoses. The Meares-Stamey four-glass test should be abandoned in favour of a simplified test comprising urine analysis before and after prostatic massage. However, the indications for this test are limited to patients in whom chronic bacterial prostatitis is suspected or with bacteriuria on urine culture.

CONCLUSION

Chronic bacterial prostatitis represents only about 5 to 10% of all cases of CP. The usual terminology of chronic non-bacterial prostatitis has been replaced by the term CPPS or CP/CPPS in men, in order to situate this disease in a broader context not exclusively related to the prostate. Despite its prevalence and its impact on quality of life and sexuality, CP/CPPS remains poorly known and continues to raise diagnostic problems.

Chlamydia trachomatisand male fertility

There is increasing evidence that the function of human spermatozoa can be significantly affected by direct exposure to the bacterium Chlamydia trachomatis. This may contribute to sub-fertility in infected individuals by a route that is independent of any damage to the reproductive epithelium. In addition, if a C. trachomatis infection is undiagnosed it could contribute to poor outcomes in assisted conception techniques such as in vitro fertilization. The antibiotics routinely used in IVF culture systems are largely ineffective against chlamydia, emphasizing the importance of screening patients prior to treatment. Moreover, given the many thousands of semen samples provided for analysis by men in primary care (many of which will never undergo assisted conception treatment), it is suggested that this may represent a wasted opportunity to provide screening (and treatment) for the infection using an appropriate test specimen and without the need for additional hospital visits.

Screening of an antigen target for immunocontraceptives from cross-reactive antigens between human sperm and Ureaplasma urealyticum

Epidemiologic studies indicated that some infertile men who were infected with Ureaplasma urealyticum displayed positive antisperm antibodies in their serum and/or semen. The purpose of this study was to investigate the possible mechanism of antisperm antibodies production after infection with U. urealyticum and to analyze the relationship between U. urealyticum and infertility. The existence of cross-reactive antigens (61, 50, and 25 kDa) between U. urealyticum and human sperm membrane proteins was confirmed. Among the cross-reactive antigens, the urease complex component UreG of U. urealyticum was determined. By searching the Swiss-Prot protein database, a pentapeptide identity (IERLT) between UreG and human nuclear autoantigenic sperm protein (NASP) was found. Furthermore, using Western blot analysis and enzyme-linked immunosorbent assay, the cross-reaction between the NASP and UreG was verified. Both anti-rUreG antibody and the antiserum against the synthetic peptide NASP393-408 containing the pentapeptide inhibited mouse sperm egg binding and fusion. After immunization by rUreG or the synthetic peptide, 81.2 and 75% female mice became sterile, respectively. The effect on fertility in mice immunized with the synthetic peptide was reversible. These findings proved for the first time that it was feasible to screen antigens for immunocontraceptives from cross-reactive antigens between sperm and microorganisms which induce infertility.

Transmission risk of hepatitis C virus via semen during assisted reproduction: how real is it?

The risk of viral transmissibility in assisted reproduction is still a much-debated issue, especially for hepatitis C virus (HCV). HCV is a common causative agent for parenterally transmitted viral hepatitis. In addition, it has been incriminated in other routes of transmission, including sexual transmission and nosocomial infections. The management of infertility, in association with HCV, has sparked debates about the potential risk of spread of infection to virus-free individuals, embryos and/or semen. The lack of worldwide-accepted screening policies has helped to fuel this debate. Today, it is evident that there is a potential risk of spread of HCV through biological fluids, including semen, to other individuals. This risk can only be marginalized by the use of well-established criteria for safety in infertility centres, and by the use of proper initial detection and segregation of potentially hazardous materials. Techniques and protocols have been established to help the andrologist and embryologist to safeguard patients against such dangers, and should be imposed in all centres, allowing HCV-positive males to enter their assisted reproduction programmes.

Effect of contaminated preprocessed semen on fertilization rate and embryo quality in assisted reproductive techniques

We aimed to identify the sources and prevalence of semen contamination from mastrubation and determine the effect of bacterospermia on fertilization rate and embryo quality in standard in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). This was a prospective controlled study, in an IVF unit of a university teaching hospital, of 93 consecutive couples undergoing IVF-embryo transfer cycles. We evaluated handwashing; semen collection and processing; and assisted reproductive technology using semen provided by masturbation. The main outcome measures were presence and type of micro-organisms in the semen samples and embryo culture medium; the effect of hand washing on rate of contamination; and the effect of semen contamination on fertilization rate and embryo quality. The first consecutive 52 men of the 93 couples were not instructed to wash their hands before masturbation, and the remainder were so instructed. Forty-nine semen cultures (94.2%) in the first group were contaminated compared to only 16 (39%) in the second (p < 0.016); 27 of the 65 positive cultures (41.5%) were contaminated by more than one organism. The most common contaminators were bacteria usually found on the skin. All but four embryo medium cultures were negative. There was no significant difference in fertilization rate and embryo quality by culture findings in either the IVF or the ICSI procedures. We found that a high percentage of manually obtained semen for standard IVF or ICSI procedures was contaminated, but this had no effect on fertilization rate and embryo quality.

PCR methods in clinical investigations of human ureaplasmas: a minireview

Human ureaplasmas are small, cell-wall-deficient organisms that are implicated in many human infections. Due to their small size and fastidious growth requirements, ureaplasmal infections are hard to diagnose clinically, and ureaplasmal disease is difficult to study in clinical samples. Standard culture methods for ureaplasmas are technically challenging, and 3 to 5 days are required to identify this pathogen. PCR methods have been increasingly used in the diagnosis of these infections and in the study of this pathogen in human specimens from multiple sites. These methods have theoretical advantages over traditional culture methods. Organism identification can occur in the presence of low numbers of bacteria, and viability is not necessary. Rapid identification of organisms within 24 h is also possible. In addition, subtyping of isolates can be performed faster with PCR methods than with culture methods. The use of PCR methods in translational research in multiple human ureaplasmal diseases will be reviewed in this paper, and their usefulness will be compared to culture methods.

The role of Chlamydia trachomatis in prostatitis

Ascending chlamydial infections have been thought to be an infective cause of prostatitis for the last three decades. Unfortunately, the definitive association between isolation of an infective agent and its prostatic origin is limited by various factors, although modern techniques of molecular biology for identification of the microorganisms are available. Two major problems are: (1) diagnostic material passing the urethra may reflect only urethral contamination, (2) prostatic biopsy specimens from the gland may also contain urethral material. The ejaculate has the same limitations, and an ideal test for detection of Chlamydia species in ejaculate specimens is not available yet. Investigations for local chlamydial IgA-antibodies may be useful; the overlap with Chlamydia pneumoniae and Chlamydia psittaci means a clear differentiation on an type-specific basis is necessary, which is normally provided by the 'elaborate' microimmunofluorescence test. Modern p-ELISAs using major outer membrane protein parts as antigens may deliver identical results in the future. In the follow-up of standardized prostatitis patients, a combination of such urological tests in EPS and seminal plasma combined with genital chlamydial DNA material, may further elucidate the chlamydial aetiology of prostate infection.

[Genital infection and infertility]

BACKGROUND

Genital infection is the most important cause of infertility worldwide, affecting not only Fallopian tubes but all anatomic urogenital sites, both male and female.

METHODS

We present a randomized,prospective and normalized study about sexually transmitted diseases(STD). We include 487 patients, 376 of whom were infertile and the remaining 111 were not and act as control group.

RESULTS

47.3% of infertile patients showed at least one infection: 10.7% had Chlamydia trachomatis infection, whereas only 0.3% had gonococal infection. We found none syphilis. 12.9% of the patients showed yeast belonging to genus Candida, 5% bacterial vaginosis, 3.8% Escherichia coli and 0.3% Klebsiella pneumoniae. The percentage of isolation of Ureaplasma urealyticum and Mycoplasma hominis were 23.5% and 4.8%, respectively. We detected antibodies against Hepatitis B (any serological marker) in 7.8% of the cases. Chlamydial infection and the presence of U. urealyticum were related with infertility (X 12=6,070, p<0.005 and X12=8,782, p<0.005,respectively).

CONCLUSIONS

We think these results conclude that is necessary to perform routine tests to screen for C. trachomatis, N. gonorrhoeae, and for infections caused by micoplasma as well, among infertile patients. These patients must be considered of being at risk of acquiring STD, since the percentage of these diseases is higher than the percentage we found among the control group. It is important to insist on prevention and early diagnosis and treatment as a main goal to decrease the number of tubal occlusion and infertile couples.