Seminal Corynebacterium strains in infertile men with and without leucocytospermia

Vertical transmission of microbiomes into embryo culture media and its association with assisted reproductive outcomes

RESEARCH QUESTION

Can microbes vertically transmit from semen and follicular fluid to embryo culture media during assisted reproductive technology (ART) treatment?

DESIGN

Spent embryo culture media (SECM), seminal fluid and follicular fluid samples were collected from 61 couples with infertility undergoing ART treatment at the Prince of Wales Hospital, Hong Kong SAR, China. Metagenomic analysis was conducted using 16s rRNA sequencing to identify the source of microbes in SECM, correlation between the semen microbiome and male infertility, and correlation between the follicular fluid microbiome and female infertility.

RESULTS

Microbial vertical transmission into SECM was reported in 82.5% of cases, and semen was the main source of contamination in conventional IVF cases. The increased abundances of Staphylococcus spp. and Streptococcus anginosus in semen had negative impacts on total motility and sperm count, respectively (P < 0.001). Significant increases in abundance of the genera Prophyromonas, Neisseria and Facklamia were observed in follicular fluid in women with anovulation, uterine factor infertility and unexplained infertility, respectively (P < 0.01). No significant correlation was found between the bacteria identified in all sample types and ART outcomes, including fertilization rate, embryo development, number of available embryos, and clinical pregnancy rate.

CONCLUSION

Embryo culture media can be contaminated during ART treatment, not only by seminal microbes but also by follicular fluid and other sources of microbes. Strong correlations were found between specific microbial taxa in semen and sperm quality, and between the follicular fluid microbiome and the aetiology of female infertility. However, no significant association was found between the microbiomes of SECM, semen and follicular fluid and ART outcomes.

Impaired Semen Quality in Patients with Chronic Prostatitis

Background/Objectives: Chronic prostatitis/chronic pelvic pain syndrome CP/CPPS is a rather common condition and in recent years many studies have shown contradictory results regarding its impact on semen quality. This prospective cohort study set out to investigate how CP/CPPS affected the parameters of semen in a prospective cohort of patients compared with the WHO 2021 reference group. Methods: From 2013 to 2022, a total of 1071 patients with suspicion of CP/CPPS received a comprehensive andrological examination. Complete semen analysis was carried out in compliance with WHO 2010 guidelines, comparing every study population semen variable to the WHO 2021 reference group (n~3500). Results: All evaluated semen parameters had median values that fell within a normal range. Nonetheless, approximately 25% of patients had values for each semen variable that were lower than the WHO reference group's fifth percentile. In particular, bacteriospermia was associated with a negative impact on semen volume. Conclusions: This is the largest study that compares all standard semen parameters in patients suffering from CP/CPPS to WHO 2021 reference values. It provides evidence of an impairment of conventional semen parameters.

Leukocytospermia and/or Bacteriospermia: Impact on Male Infertility

Infertility is a globally underestimated public health concern affecting almost 190 million people, i.e., about 17.5% of people during their lifetime, while the prevalence of male factor infertility is about 7%. Among numerous other causes, the prevalence of male genital tract infections reportedly ranges between 10% and 35%. Leukocytospermia is found in 30% of infertile men and up to 20% in fertile men. Bacterial infections cause an inflammatory response attracting leukocytes, which produce reactive oxygen species (ROS) and release cytokines, both of which can cause damage to sperm, rendering them dysfunctional. Although leukocytospermia and bacteriospermia are both clinical conditions that can negatively affect male fertility, there is still debate about their impact on assisted reproduction outcomes and management. According to World Health Organization (WHO) guidelines, leukocytes should be determined by means of the Endtz test or with monoclonal antibodies against CD15, CD68 or CD22. The cut-off value proposed by the WHO is 1 × 106 peroxidase-positive cells/mL. For bacteria, Gram staining and semen culture are regarded as the "gold standard", while modern techniques such as PCR and next-generation sequencing (NGS) are allowing clinicians to detect a wider range of pathogens. Whereas the WHO manual does not specify a specific value as a cut-off for bacterial contamination, several studies consider semen samples with more than 103 colony-forming units (cfu)/mL as bacteriospermic. The pathogenic mechanisms leading to sperm dysfunction include direct interaction of bacteria with the male germ cells, bacterial release of spermatotoxic substances, induction of pro-inflammatory cytokines and ROS, all of which lead to oxidative stress. Clinically, bacterial infections, including "silent" infections, are treatable, with antibiotics being the treatment of choice. Yet, non-steroidal antiphlogistics or antioxidants should also be considered to alleviate inflammatory lesions and improve semen quality. In an assisted reproduction set up, sperm separation techniques significantly reduce the bacterial load in the semen. Nonetheless, contamination of the semen sample with skin commensals should be prevented by applying relevant hygiene techniques. In patients where leukocytospermia is detected, the causes (e.g. infection, inflammation, varicocele, smoking, etc.) of the leukocyte infiltration have to be identified and addressed with antibiotics, anti-inflammatories or antioxidants in cases where high oxidative stress levels are detected. However, no specific strategy is available for the management of leukocytospermia. Therefore, the relationship between bacteriospermia and leukocytospermia as well as their specific impact on functional sperm parameters and reproductive outcome variables such as fertilization or clinical pregnancy must be further investigated. The aim of this narrative review is to provide an update on the current knowledge on leukocytospermia and bacteriospermia and their impact on male fertility.

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.

The effect of seminal pathogens on standard semen parameters, sperm kinematics and seminal inflammatory markers

This study evaluated the effects of urogenital pathogens on standard semen parameters, sperm kinematics and host inflammatory response in a cohort of asymptomatic subfertile men. There were six groups based on the results of bacterial culture, including Ureaplasma urealyticum (U. Urealyticum) (n = 27), mixed comprising two or more pathogenic species (n = 28), Gardnerella Vaginalis (G. Vaginalis) (n = 15), gram-positive cocci and bacilli (g+cocci/bacilli) (n = 15), gram-negative bacilli (g-bacilli) (n = 10) and Chlamydia trachomatis (C. trachomatis) (n = 2). One control group (n = 20) and one leukocytospermic group (n = 10) were also included. Sperm quality parameters, seminal leukocytes and interleukin (IL)-6 of all groups, apart from C. trachomatis, were compared to the control group. Standard semen parameters were significantly worse in all groups except for that with g-bacilli. Progressive motility, total motility and normal sperm morphology demonstrated the most significant differences, when U. Urealyticum, leukocytospermia and mixed pathogens were detected in semen. Among sperm kinematics, the concentration of progressive motile sperm cells (CPMS), the percentage of progressive motile sperm cells (PPMS) and straightness (STR) were manifested significant declines in the presence of seminal pathogens. CPMS was affected in all groups except for G. vaginalis. Moreover, the presence of g+cocci/bacilli and g-bacilli were associated with increased seminal IL-6. Seminal leukocytes were elevated significantly only when g-bacilli were cultured in semen. We conclude that seminal pathogens can negatively affect sperm quality. The most negative effect is related to U. Urealyticum. Moreover, g+cocci/bacilli and g-bacilli can initiate an inflammatory response.

The microbiome and male infertility: looking into the past to move forward

The human body harbours trillions of microbes, and their influence on human health has been explored in many parts of the human body, including the male reproductive system. From routine culturing to polymerise chain reaction (PCR) and high throughput DNA sequencing, several studies have identified bacteria in the male reproductive system. In this review, we discuss the past and current literature surrounding the testicular and semen microbiome in correlation with male infertility. We further highlight the potential benefits of probiotics as an alternative therapeutic option for male infertility. Although not conclusive, emerging data are indicating potential implications of certain bacterial members on male fertility. There is a general agreement on the negative impact of some pathogenic bacterial species on semen parameters, including sperm counts, motility, morphology, and DNA integrity. On the other hand, Lactobacillus, known as a human-friendly bacteria, has shown protective effects on semen parameters, which makes it a potentially good probiotic. In order to confirm the findings of previous studies, more clinical studies with larger sample sizes and the right controls are needed.

Pilot Study: Next-generation Sequencing of the Semen Microbiome in Vasectomized Versus Nonvasectomized Men

BACKGROUND

Approximately half a million vasectomies are performed every year in the USA. There is a paucity of literature on the impact of male sterilization on the semen microbiome and whether it prompts microbiota dysbiosis.

OBJECTIVE

To investigate if vasectomy induces changes in the seminal microbiome via comparison of semen samples from men before and after vasectomy, and if the seminal microbiome profiles for vasectomized men follow a particular pattern with respect to diversity and abundance.

DESIGN, SETTING, AND PARTICIPANTS

From July 2021 to February 2022, we prospectively collected and analyzed semen samples from 58 men at one outpatient clinic. Eighteen men provided a semen sample before and 3 mo after vasectomy. We also collected semen samples from 22 fertile nonvasectomized men and from a further 18 vasectomized men at 3 mo after vasectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Semen microbiome α-diversity, beta-diversity, and relative abundance were compared initially between paired and then between unpaired vasectomized and nonvasectomized samples. Analysis of variance (ANOVA), permutational multivariate ANOVA, and analysis of the composition of microbiomes with bias correction were used to assess differences.

RESULTS AND LIMITATIONS

In both paired and unpaired sets of samples, a decreasing trend for α-diversity in semen after vasectomy was observed. Shannon diversity, the relative abundance of species with an abundance >2%, and composition were not significantly changed. Sphingomonas, Brevundimonas, and Paracoccus abundance decreased after vasectomy, while Corynebacterium abundance increased. The results may be limited by the sample size and lack of demographic heterogeneity.

CONCLUSIONS

Vasectomy is followed by a decrease in α-diversity and changes in the relative abundance of bacterial species in the semen microbiome. Further investigation is necessary to understand the clinical significance of these changes after vasectomy.

PATIENT SUMMARY

We evaluated changes in the bacteria species in semen after vasectomy. We found that vasectomy decreased the richness and evenness of bacteria species in semen, but the overall bacterial community remained similar. Further studies are needed to assess the implications of changes in semen bacteria after vasectomy.

Corynebacterium glucuronolyticum in men with and without urethritis syndrome: An underrecognized pathogen or a bona fide commensal?

BACKGROUND

By analysing the largest collection of Corynebacterium glucuronolyticum (C. glucuronolyticum) isolates from a single centre thus far, we aimed to appraise a potential causal link between an infrequently isolated species and the urethritis syndrome in men.

METHODS

A total of 1055 Caucasian male individuals with or without urethritis syndrome were included in this single-centre case-control study. Group-wise comparisons were pursued by analysing sociodemographic, behavioural and microbiological specificities between the two groups. C. glucuronolyticum isolates from urethral specimens were identified using the analytical profile index biotyping system (API Coryne) and additionally confirmed by MALDI-TOF mass-spectrometry, with subsequent determination of their antimicrobial sensitivity profiles. Statistical significance was set at p < 0.05 (two-tailed).

RESULTS

C. glucuronolyticum was isolated in 5.08% of study participants with urethritis syndrome and 3.60% of those without it (p = 0.303). In the urethritis group, the species was more frequently found as a sole isolate (p = 0.041) and after prior infection with Chlamydia trachomatis (p = 0.025). The most frequent presentation of urethritis included a clear discharge in small or moderate amounts, without any pathognomonic findings. The resistance rates were 62.22% for clindamycin, 42.22% for tetracycline and 26.67% for ciprofloxacin.

CONCLUSIONS

Our study provides major insights on the relevance of urethral C. glucuronolyticum in non-gonococcal urethritis, with significant implications for further aetiological research and management approaches.

Bacteriospermia - A formidable player in male subfertility

Bacterial colonization of male reproductive tissues, cells, and fluids, and the subsequent impact of bacteria on the sperm architecture, activity, and fertilizing potential, has recently gained increased attention from the medical and scientific community. Current evidence strongly emphasizes the fact that the presence of bacteria in semen may have dire consequences on the resulting male fertility. Nevertheless, the molecular basis underlying bacteriospermia-associated suboptimal semen quality is sophisticated, multifactorial, and still needs further understanding. Bacterial adhesion and subsequent sperm agglutination and immobilization represent the most direct pathway of sperm-bacterial interactions. Furthermore, the release of bacterial toxins and leukocytic infiltration, associated with a massive outburst of reactive oxygen species, have been repeatedly associated with sperm dysfunction in bacteria-infested semen. This review serves as a summary of the present knowledge on bacteriospermia-associated male subfertility. Furthermore, we strived to outline the currently available methods for assessing bacterial profiles in semen and to outline the most promising strategies for the prevention and/or management of bacteriospermia in practice.

A comparison of different O-antigen serogroups of Escherichia coli in semen samples of fertile and infertile men

Objective

Male genital tract infections have been associated with infertility, and Escherichia coli has drawn increasing attention as an important bacterium in this context. This investigation aimed to characterize and compare the distributions of O-antigen serogroups of E. coli in the semen samples of fertile and infertile men.

Methods

In this case-control study, semen samples were collected from 618 fertile and 1,535 infertile men. The E. coli-positive samples were evaluated in terms of concentration, morphology, viability, and motility parameters according to the World Health Organization 2010 guidelines. Finally, different serogroups of E. coli were identified by multiplex polymerase chain reaction targeting the O-antigen variations of the bacterium.

Results

The prevalence of E. coli among fertile men was significantly higher than among infertile men (p<0.001). The sperm morphology, viability, and motility in the E. coli-positive fertile group were significantly higher than in the E. coli-positive infertile group (p<0.001). E. coli O6 was the most prevalent serogroup found in both groups. However, there was no significant difference in the frequency of different serogroups of E. coil between the two groups (p=0.55).

Conclusion

Despite the higher prevalence of E. coli among fertile men, E. coli had more detrimental effects on semen parameters in infertile men. There was no significant difference in E. coli serogroups between the fertile and infertile groups.

Using the PCR and Blood Agar in Diagnosis of Semen Bacterial Contamination of Fertile and Infertile Men

BACKGROUND

One of the causes of male infertility is Genital tract infections (GTI). Considering the importance of GTI, widespread recognition of them seems necessary. we aimed to characterize and compare semen microbial populations in fertile and infertile men who referred to an infertility clinic in Yazd, Iran.

METHODS

Semen samples were collected from two groups of fertile (268) and infertile (210) men. Sperm analysis (concentration, morphology, viability and motility parameters) were performed according to the World Health Organization (WHO) 2010 guidelines laboratory manual. Bacterial isolation was performed in Sheep Blood Agar and Eosin Methylene Blue (EMB) agar plates. For PCR, samples were analyzed with genus specific primers.

RESULTS

All semen characteristics were poor in the infertile group compared to those in the fertile men (p-value< 0.05). Enterococcus spp. (18.7%, 17.1%; p= 0.814), E. coli (7.9%, 11.4%; p= 0.486), Staphylococcus aureus (6.4%, 2.9%; p= 0.398) and Proteus mirabilis (0%, 2.9%; p= 0.002) were the most common agents, respectively. Also, the results obtained from PCR were confirmed using culture-base method.

CONCLUSION

Proteus mirabilis contamination was identified in the infertile group. While no significant association was observed between male infertility and semen microbial populations, p. mirabilis may be the leading cause of reproduction impairment in men.

Role of Lactobacillus in Female Infertility Via Modulating Sperm Agglutination and Immobilization

Infertility has become a common problem in recent decades. The pathogenesis of infertility is variable, but microbiological factors account for a large proportion of it. Dysbiosis of vaginal microbiota is reportedly associated with female infertility, but the influence of normal vaginal microbiota on infertility is unclear. In this review, we summarize the physiological characteristics of the vaginal tract and vaginal microbiota communities. We mainly focus on the bacterial adherence of vaginal Lactobacillus species. Given that the adherent effect plays a crucial role in the colonization of bacteria, we hypothesize that the adherent effect of vaginal Lactobacillus may also influence the fertility of the host. We also analyze the agglutination and immobilization effects of other bacteria, especially Escherichia coli, on ejaculated spermatozoa, and speculate on the possible effects of normal vaginal microbiota on female fertility.

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.

Microbiota and Human Reproduction: The Case of Male Infertility

The increasing interest in metagenomics is enhancing our knowledge regarding the composition and role of the microbiota in human physiology and pathology. Indeed, microbes have been reported to play a role in several diseases, including infertility. In particular, the male seminal microbiota has been suggested as an important factor able to influence couple's health and pregnancy outcomes, as well as offspring health. Nevertheless, few studies have been carried out to date to deeper investigate semen microbiome origins and functions, and its correlations with the partner's reproductive tract microbiome. Here, we report the state of the art regarding the male reproductive system microbiome and its alterations in infertility.

The seminal microbiome in health and disease

Owing to the fact that there are more microbial than human cells in our body and that humans contain more microbial than human genes, the microbiome has huge potential to influence human physiology, both in health and in disease. The use of next-generation sequencing technologies has helped to elucidate functional, quantitative and mechanistic aspects of the complex microorganism-host interactions that underlie human physiology and pathophysiology. The microbiome of semen is a field of increasing scientific interest, although this microbial niche is currently understudied compared with other areas of microbiome research. However, emerging evidence is beginning to indicate that the seminal microbiome has important implications for the reproductive health of men, the health of the couple and even the health of offspring, owing to transfer of microorganisms to the partner and offspring. As this field expands, further carefully designed and well-powered studies are required to unravel the true nature and role of the seminal microbiome.

A microbial game of whack-a-mole: clinical case series of the urethral uncloaking phenomenon caused by Corynebacterium glucuronolyticum in men treated for Chlamydia trachomatis urethritis

Corynebacterium glucuronolyticum is a rare and neglected, but increasingly recognized bacterial agent of infectious urethritis and other genitourinary syndromes in men. This is the first description of its proclivity to resurface as a cause of sustained urethritis in male patients previously treated for Chlamydia trachomatis, which represents a phenomenon that has to be differentiated from a simple post-treatment overgrowth of a colonizing agent.

[Bacteriospermia: Effects on semen parameters]

OBJECTIVES

Bacteriospermia may result in male hypofertlity. Indeed, 60% of patients treated by Assisted Reproductive Techniques had a local infection or inflammation of genital tract. However, direct effects of bacteriospermia on semen parameters remain controversial. The aim of our work was to explore the effect of bacteriospermia on sperm parameters among patients consulting for hypofertility.

METHODS

A retrospective comparative study of two groups: a group of 70 patients with bacteriospermia (group 1) and a control group of 70 patients without bacteriospermia (group 2). For these groups, we studied the standard semen parameters (seminal volume and viscosity and spermatozoa count, initial and secondary mobility, vitality and morphology). Comparison of these parameters was made by the Chi² test and the Fisher test.

RESULTS

The mean age of our population was 40.4±6.7 years. There was no significant difference between ejaculate average volume in the 2 groups (group B: 2.78mL versus group A: 2.92mL with P=0.2). Similarly, for the viscosity no difference was noted (P=0,68). The altered parameters in the presence of bacteriospermia were mean concentration and sperm motility (P=0.001 and P=0.049 respectively). The prevalence of secondary asthenospermia was higher in the presence of bacterospermia (P=0.006). No statistically significant differences were observed for morphology and vitality of spermatozoa (P=0.276 and P=0.075 respectively). The leucospermia was associated with bacteriospermia in 10% patients. Ureaplasma urealyticum was the germ most found (45.7%) followed by Streptococcus and Staphylococcacae (20.3% for each), Gram negative rods accounted for 12.9%, while Corynebacterium spp was isolated only in 4,3% patients. U. urealyticum was associated with hypospermia in 33% of cases (P=0.031). Spermatozoa motility was significatively decreased not only in the presence of this bacteria (FT=0.002) but also when cultures were positive for Streptococcus (0.04) and Corynebacterium (P<0.001). Morphological abnormalities were also noticed with Streptococcus with index of teratozoospermia of 46% versus 19% in the 2nd group (P=0.046).

CONCLUSION

Bacteriospermia may impair sperm parameters. The treatment of this affection seems to improve sperm fertilizing potential. In addition, it could prevent contamination of culture media.

The impact of Corynebacterium glucuronolyticum on semen parameters: a prospective pre-post-treatment study

Corynebacterium glucuronolyticum (C. glucuronolyticum) is a rare isolate that is only recently being acknowledged as a potential urogenital pathogen. The bibliographical references on this bacterial species are scarce, and its influence on all semen parameters was hitherto unknown - therefore, the aim of this study was to evaluate its effects on a range of sperm quality parameters. A prospective approach to compare semen parameters before and after treatment was used in this study. C. glucuronolyticum in semen specimens was identified using analytical profile index biotyping system (API Coryne) and additionally confirmed by matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS), with the determination of antimicrobial susceptibility by Kirby-Bauer method. Semen analysis was performed according to the criteria from the World Health Organization (with the use of Tygerberg method of sperm morphology categorization). Very strict inclusion criteria for participants also included detailed medical history and urological evaluation. From a total of 2169 screened semen specimens, the inclusion rate for participants with C. glucuronolyticum that satisfied all the criteria was 1.01%. Antibiogram-guided treatment of the infection with ensuing microbiological clearance has shown that the resolution of the infection correlates with statistically significant improvement in the vitality of spermatozoa, but also with a lower number of neck and mid-piece defects. Parameters such as sperm count, motility and normal morphology were not affected. In addition, susceptibility testing revealed a trend towards ciprofloxacin resistance, which is something that should be considered when selecting an optimal treatment approach. Albeit it is rarely encountered as a monoisolate in significant quantities, C. glucuronolyticum may negatively influence certain sperm parameters; therefore, it has to be taken into account in the microbiological analysis of urogenital samples.