Bidirectional Mendelian randomization to explore the causal relationships between the gut microbiota and male reproductive diseases.

Gut bacteria might play an important role in male reproductive disorders, such as male infertility and sperm abnormalities; however, their causal role is unclear. Herein, Mendelian randomization (MR)-Egger, weighted median, inverse variance weighting, Simple mode, and Weighted mode were used to test the causal relationship between gut microbes and male reproductive diseases. The MR results were validated using various metrics. The MR results were also consolidated using reverse causality speculation, conducted using two-way MR analysis and Steiger filtering. Biological function was analysed using enrichment analyses. The results suggested that eight intestinal microflorae were causally associated with male infertility. The Eubacterium oxidoreducens group was associated with an increased risk of male infertility, while the family Bacteroidaceae was negatively associated with male reproductive diseases. Eight intestinal microflorae were causally associated with abnormal spermatozoa. The family Streptococcaceae was associated with a high risk of abnormal spermatozoa, whereas the family Porphyromonadaceae was associated with a low risk of abnormal spermatozoa. No pleiotropy was observed, this study identified a high correlation between the gut flora and the likelihood of male reproductive diseases. Future research will attempt to advance microbial-focused treatments for such diseases.

Male Tract Microbiota and Male Infertility.

In recent years, several studies have analyzed the composition of the male genital tract microbiota and its changes in infertility or in different situations associated with infertility. The aim of this narrative review is to obtain more insight on this topic; in particular, to describe actual evidence about changes in the semen microbiota in patients with infertility, male tract infections, or HPV infections. In semen, an increase in semen Prevotella spp. is associated with oligozoospermia and with obesity-associated asthenozoospermia; an increase in Pseudomonas is more frequently associated with asthenozoospermia and oligozoospermia; a reduction in Lactobacilli spp. (namely in Lactobacillus crispatus) may represent a marker of low semen quality. However, an increase in Lactobacillus iners is considered a risk factor for a reduced sperm concentration. In patients with prostatitis, there is a reduction in Lactobacillus spp. and an increase in Streptococcus spp., opening important perspectives about the role of probiotic treatments in these patients. Finally, an increase in Fusobacteria spp. was observed in patients with an HPV infection. In the conclusion, we underline the interactions between the seminal and vaginal microbiota, so that further studies should focus on the "couple genital microbiota".

Bacteriospermia in men among infertile couples in the Nepalese population.

Infection of the male urogenital tract or male accessory glands is considered one of the important causes of male infertility, and results in the presence of bacteria in semen affecting the fertility potential of men. This study aims to understand the rate of seminal infection in infertile men, and its association with semen parameters related to fertility potential. The study was carried out from June 2021 to July 2022, in which 217 semen samples were collected from male partners of couples consulting for fertility complaints in a fertility center in Nepal. Analysis of semen parameters was done following the WHO guidelines for human semen analysis, 2021. Microbiological assessment of semen by culture-based approach showed bacteriospermia among 25.3% of samples. Staphylococcus aureus was the predominant isolate in semen. The volume of semen was reduced (p = 0.001 at 95% confidence interval) with bacteriospermia. The concentration, total motility, morphology, and vitality of spermatozoa in the samples tended to be negatively impacted due to bacteriospermia, however, the associations were insignificant at 95% CI. Our study indicates impairment of semen parameters is partially associated with bacterial infection, and hence bacteriospermia may be an important cause of male infertility. Our data represent a baseline for future in-depth studies on bacterial infection in the semen of infertile men in Nepal.

[Analysis of genital chlamydia and gonococcal infections in infertility].

To analyze the infection of chlamydia (CT) and gonorrhea (NG) in female infertility and male infertility population, and to explore the correlation between CT and NG infection and infertility. A case-control study was conducted to retrospectively analyze the specimens submitted by patients from the Third Xiangya Hospital of Central South University from January 2021 to December 2022. The results showed that a total of 32 184 specimens were collected, and the positive rates of CT were 4.41% (1 419/32 184), and positive rats of NG were 1.42% (457/32 184). In the infertility group (n=3 366), 2 987 were females and 379 were males. In the control group (n=3 366), 2 509 were females and 857 were males. The CT positive rate of the infertility group was 13.61% (458/3 366), which was significantly higher than that of the control group 3.30% (111/3 366), and the difference was statistically significant (χ2=4.245, P<0.05), and the NG positive rate of the infertility group was 6.36% (214/3 366), which was significantly higher than that of the control group 0.89% (30/3 366), and the difference was statistically significant (χ2=4.011, P<0.05). A total of 23 992 female genital tract swab specimens were collected, including 2 987 in the infertility group and 2 509 in the control group, and the positive rate of CT in the female infertility subgroup was 10.41% (311/2 987), which was significantly higher than that in the control group 3.75% (94/2 509), the difference was statistically significant (χ2=4.132, P<0.05), and the NG positive rate of 8.73% (261/2 987) in the female infertility subgroup was significantly higher than that in the control group 0.40% (10/2 509), and the difference was statistically significant (χ2=4.242, P<0.05). A total of 8 192 male urine samples were collected, including 379 in the infertility group and 857 in the control group, and the CT positive rate of the male infertility subgroup was 13.72% (52/379), which was significantly higher than that of the control group 3.38% (29/857), and the difference was statistically significant (χ2=5.267, P<0.05), and the positive rate of NG in the male infertility subgroup was 12.66% (48/379), which was significantly higher than that of the control group 0.93% (8/857), and the difference was statistically significant (χ2=4.166, P<0.05). Among the 2 987 female specimens in the infertility group, 1 034 were in the primary infertility subgroup and 1 953 were in the secondary infertility subgroup, and the positive rates of CT were 7.93% (82/1 034) and 15.72% (307/1 953), respectively, and the positive rates of NG were 3.87% (40/1 034) and 8.65% (169/1 953) respectively, and the difference was not statistically significant (χ2=0.185, P>0.05) and (χ2=0.002, P>0.05). In conclusion, the infection rate of genital tract CT and NG is high in the infertility population, CT and NG are recommended as routine examination indicators for eugenics and infertility screening.

A comprehensive insight into the contribution of epigenetics in male infertility; focusing on immunological modifications.

Numerous recent studies have examined the impact epigenetics-including DNA methylation-has on spermatogenesis and male infertility. Differential methylation of several genes has been linked to compromised spermatogenesis and/or reproductive failure. Specifically, male infertility has been frequently associated with DNA methylation abnormalities of MEST and H19 inside imprinted genes and MTHFR within non-imprinted genes. Microbial infections mainly result in male infertility because of the immune response triggered by the bacteria' accumulation of immune cells, proinflammatory cytokines, and chemokines. Thus, bacterially produced epigenetic dysregulations may impact host cell function, supporting host defense or enabling pathogen persistence. So, it is possible to think of pathogenic bacteria as potential epimutagens that can alter the epigenome. It has been demonstrated that dysregulated levels of LncRNA correlate with motility and sperm count in ejaculated spermatozoa from infertile males. Therefore, a thorough understanding of the relationship between decreased reproductive capacity and sperm DNA methylation status should aid in creating new diagnostic instruments for this condition. To fully understand the mechanisms influencing sperm methylation and how they relate to male infertility, more research is required.

Association between semen microbiome disorder and sperm DNA damage.

DNA fragmentation index (DFI), a new biomarker to diagnose male infertility, is closely associated with poor reproductive outcomes. Previous research reported that seminal microbiome correlated with sperm DNA integrity, suggesting that the microbiome may be one of the causes of DNA damage in sperm. However, it has not been elucidated how the microbiota exerts their effects. Here, we used a combination of 16S rRNA sequencing and untargeted metabolomics techniques to investigate the role of microbiota in high sperm DNA fragmentation index (HDFI). We report that increased specific microbial profiles contribute to high sperm DNA fragmentation, thus implicating the seminal microbiome as a new therapeutic target for HDFI patients. Additionally, we found that the amount of Lactobacillus species was altered: Lactobacillus iners was enriched in HDFI patients, shedding light on the potential influence of L. iners on male reproductive health. Finally, we also identified enrichment of the acetyl-CoA fermentation to butanoate II and purine nucleobase degradation I in the high sperm DNA fragmentation samples, suggesting that butanoate may be the target metabolite of sperm DNA damage. These findings provide valuable insights into the complex interplay between microbiota and sperm quality in HDFI patients, laying the foundation for further research and potential clinical interventions.IMPORTANCEThe DNA fragmentation index (DFI) is a measure of sperm DNA fragmentation. Because high sperm DNA fragmentation index (HDFI) has been strongly associated with adverse reproductive outcomes, this has been linked to the seminal microbiome. Because the number of current treatments for HDFI is limited and most of them have no clear efficacy, it is critical to understand how semen microbiome exerts their effects on sperm DNA. Here, we evaluated the semen microbiome and its metabolites in patients with high and low sperm DNA fragmentation. We found that increased specific microbial profiles contribute to high sperm DNA fragmentation. In particular, Lactobacillus iners was uniquely correlated with high sperm DNA fragmentation. Additionally, butanoate may be the target metabolite produced by the microbiome to damage sperm DNA. Our findings support the interaction between semen microbiome and sperm DNA damage and suggest that seminal microbiome should be a new therapeutic target for HDFI patients.

The Relationship Between Ureaplasma Species and Male Infertility: Pathogenicity, Biology, Diagnosis, and Treatment.

Objective: Ureaplasma spp. comprise a group of mycoplasmas containing two human-associated species, namely, Ureaplasma urealyticum (UUR) and Ureaplasma parvum (UPA). The characterization of Ureaplasma species as pathogens contributing to male infertility remains a subject of considerable controversy. While numerous authors have proposed a relationship between UUR and changes in fertility, there is limited evidence supporting the involvement of UPA in this context. There has been an increased focus on Ureaplasma spp. and its potential role in the development of male infertility, especially over the past few years. The review aims to clarify the relationship between Ureaplasma species and male infertility. Methods: Firstly, we introduce a background of the appropriate biology including growth characteristics, the divided biovars, and the transmission pathways. Secondly, we examine the studies that support a causal role for Ureaplasma spp. in the development of infertility in the last 30 years. Finally, the diagnosed method, antimicrobial susceptibility, and potential therapeutic considerations are evaluated. Results: UPA and UUR can impair semen motility. The species of Ureaplasma spp., the sexual history of the patient, the number of sexual partners, the load of Ureaplasma, and antimicrobial resistance are expected to constitute key risk factors in the development of male infertility. In terms of treatment, Doxycycline remains the drug of first choice for ureaplasmal infections. Conclusion: Ureaplasma spp. are not simply "innocent bystanders" in infertility and may indeed be an "underestimated enemy of human reproduction". Ureaplasma spp. can be considered an etiological agent in unexplained infertility and a useful marker.

Inflammatory cytokines may mediate the causal relationship between gut microbiota and male infertility: a bidirectional, mediating, multivariate Mendelian randomization study.

Introduction: Studies have shown that the gut microbiota is associated with male infertility (MI). However, their causal relationship and potential mediators need more evidence to prove. We aimed to investigate the causal relationship between the gut microbiome and MI and the potential mediating role of inflammatory cytokines from a genetic perspective through a Mendelian randomization approach. Methods: This study used data from genome-wide association studies of gut microbes (Mibiogen, n = 18, 340), inflammatory cytokines (NFBC1966, FYPCRS, FINRISK 1997 and 2002, n=13, 365), and male infertility (Finngen, n=120, 706) to perform two-way Mendelian randomization (MR), mediated MR, and multivariate MR(MVMR) analyses. In this study, the inverse variance weighting method was used as the primary analysis method, and other methods were used as supplementary analysis methods. Results: In the present study, two gut microbes and two inflammatory cytokines were found to have a potential causal relationship with MI. Of the two gut microorganisms causally associated with male infertility, Anaerotruncus increased the risk of male infertility (odds ratio = 1.81, 95% confidence interval = 1.18-2.77, P = 0.0062), and Bacteroides decreased the risk of male infertility (odds ratio = 0.57, 95% confidence interval = 0.33-0.96, P = 0.0363). In addition, of the two inflammatory cytokines identified, hepatocyte growth factor(HGF) reduced the risk of male infertility (odds ratio = 0.50, 95% confidence interval = 0.35-0.71, P = 0.0001), Monocyte chemotactic protein 3 (MCP-3) increased the risk of male infertility (odds ratio = 1.28, 95% confidence interval = 1.03-1.61, P = 0.0039). Mediated MR analysis showed that HGF mediated the causal effect of Bacteroides on MI (mediated percentage 38.9%). Multivariate MR analyses suggest that HGF may be one of the pathways through which Bacteroides affects MI, with other unexplored pathways. Conclusion: The present study suggests a causal relationship between specific gut microbiota, inflammatory cytokines, and MI. In addition, HGF may mediate the relationship between Bacteroides and MI.

Dysbiosis of Gut Microbiome Aggravated Male Infertility in Captivity of Plateau Pika.

Captivity is an important and efficient technique for rescuing endangered species. However, it induces infertility, and the underlying mechanism remains obscure. This study used the plateau pika (Ochotona curzoniae) as a model to integrate physiological, metagenomic, metabolomic, and transcriptome analyses and explore whether dysbiosis of the gut microbiota induced by artificial food exacerbates infertility in captive wild animals. Results revealed that captivity significantly decreased testosterone levels and the testicle weight/body weight ratio. RNA sequencing revealed abnormal gene expression profiles in the testicles of captive animals. The microbial α-diversity and Firmicutes/Bacteroidetes ratio were drastically decreased in the captivity group. Bacteroidetes and Muribaculaceae abundance notably increased in captive pikas. Metagenomic analysis revealed that the alteration of flora increased the capacity for carbohydrate degradation in captivity. The levels of microbe metabolites' short-chain fatty acids (SCFAs) were significantly high in the captive group. Increasing SCFAs influenced the immune response of captivity plateau pikas; pro-inflammatory cytokines were upregulated in captivity. The inflammation ultimately contributed to male infertility. In addition, a positive correlation was observed between Gastranaerophilales family abundance and testosterone concentration. Our results provide evidence for the interactions between artificial food, the gut microbiota, and male infertility in pikas and benefit the application of gut microbiota interference in threatened and endangered species.

Urine microbes and predictive metagenomic profiles associate with abnormalities in sperm parameters: implications for male subfertility.

OBJECTIVE: To explore the taxonomic and predicted functional relationship between the urine microbiome and alterations of semen analysis (SA) parameters. DESIGN: Cross-sectional study. SETTING: Academic medical center. PATIENT(S): Men presenting for fertility evaluation or men presenting for vasectomy consultation with proven biological paternity were recruited and stratified on the basis of alterations, or lack thereof, in SA parameters. MAIN OUTCOME MEASURE: Changes in the functional and taxonomic urine microbiome profiles of participants with or without alterations in SA parameters. RESULTS: Seventy-three participants were included in our study. Men with abnormal sperm motility (N = 27) showed a nearly 50-fold higher abundance of Dialister micraerophilus compared with those with normal sperm motility (N = 46). This relationship persisted on canonical correlational analysis (r = 0.439). Men with abnormal sperm concentration (N = 20) showed a lower abundance of Enterococcus faecalis and Staphylococcus aureus, compared with those with normal sperm concentration (N = 53). The urine of participants with impaired sperm motility demonstrated dramatic differences in predictive functional profiles in pathways involved in oxidation-reduction balance and cell longevity. CONCLUSIONS: Our findings underscore differences in the urinary microbiome and abnormalities in semen parameters, especially sperm motility. By incorporating predictive functional profiling, we also highlight possible mechanisms that may drive the observed differences in sperm parameters.

Impact of semen microbiota on the composition of seminal plasma.

Several studies have found associations between specific bacterial genera and semen parameters. Bacteria are known to influence the composition of their niche and, consequently, could affect the composition of the seminal plasma. This study integrated microbiota profiling and metabolomics to explore the influence of seminal bacteria on semen metabolite composition in infertile couples, revealing associations between specific bacterial genera and metabolite profiles. Amino acids and acylcarnitines were the predominant metabolite groups identified in seminal plasma. Different microbiota profiles did not result in globally diverse metabolite compositions in seminal plasma. Nevertheless, levels of specific metabolites increased in the presence of a dysbiotic microbiota. Urocanate was significantly increased in abnormal semen samples (adjusted P-value < 0.001) and enriched in samples dominated by Prevotella spp. (P-value < 0.05), which was previously linked to a negative impact on semen. Therefore, varying microbiota profiles can influence the abundance of certain metabolites, potentially having an immunomodulatory effect, as seen with urocanate.IMPORTANCEMale infertility is often considered idiopathic since the specific cause of infertility often remains unidentified. Recently, variations in the seminal microbiota composition have been associated with normal and abnormal semen parameters and may, therefore, influence male infertility. Bacteria are known to alter the metabolite composition of their ecological niches, and thus, seminal bacteria might affect the composition of the seminal fluid, crucial in the fertilization process. Our research indicates that distinct seminal microbiota profiles are not associated with widespread changes in the metabolite composition of the seminal fluid. Instead, the presence of particular metabolites with immunomodulatory functions, such as urocanate, could shed light on the interplay between seminal microbiota and variations in semen parameters.

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.

Diagnosis of bacteriospermia and its impact on spermogram parameters in adolescents with varicocele.

Infectious etiology is the cause of about 15% of cases of male infertility. And if sexually transmitted infections are easily diagnosed, the role of asymptomatic bacteriospermia in the formation of infertility in men, and especially in adolescents against the background of the existing pathology of the reproductive sphere (varicocele), remains insufficiently studied. A microbiological study in the ejaculate of adolescents revealed the following types of bacteria: Escherichia coli, Enterococcus faecalis, Corynebacterium glucuronolyticum, Corynebacterium minitissimum, Streptococcus anginosus, Staphylococcus epidermidis, Staphylococcus haemolyticus. Bacteria in the ejaculate were also detected during semen analysis and electron microscopic examination of spermatozoa. With abundant growth of microorganisms in a monoculture or an association of two microorganisms present in a moderate amount, in all cases, violations of sperm motility, an increase in the viscosity of the ejaculate, the presence of leukocytes in the seminal fluid were detected, and damage to the chromatin, acrosome and mitochondria was recorded at the ultrastructural level, which may indicate active infection. When bacterial flora was detected in a small and moderate amount (<10 CFU/ml), no pathological changes in the ejaculate were observed. The microflora of the ejaculate of the examined adolescents is represented by gram-positive microflora. Simultaneous study of the ejaculate sample by bacteriological seeding, the performance of spermogram and EMIS allowed to increase the detection of bacteriospermia. Opportunistic pathogens with abundant growth or their various combinations can serve as a factor in the development of pathospermia. It is possible to distinguish an active infection from commensal microflora or sample contamination not only by the presence of bacteria in the ejaculate and their quantitative accounting, but also by the degree of damage to the function of spermatozoa and pathological changes in the parameters of the ejaculate, by combining diagnostic methods. Most often, in the presence of bacteria in the ejaculate, asthenozoospermia is diagnosed.

Asymptomatic bacteriospermia and infertility-what is the connection?

OBJECTIVE: To determine the impact of asymptomatic bacteriospermia on semen quality in subfertile men. METHODS: We conducted a retrospective, single-centre cohort study in 1300 subfertile men. In those diagnosed with asymptomatic bacteriospermia we performed univariate and multivariate logistic regression models to evaluate the strain-specific association with semen parameters. RESULTS: Asymptomatic bacteriospermia was diagnosed in 3.2% of patients. The microbiological semen analysis revealed a poly-microbial result in 60%. The most common bacterial species were coagulase-negative Staphylococci species (71.4%), Streptococcus viridans (50.0%) and Enterococcus faecalis (26.2%). Sexually transmitted pathogens were identified in 11.9% of semen samples. The detection of Streptococcus viridians or Haemophilus parainfluenzae correlated with impaired sperm morphology (p < 0.05). The presence of coagulase-negative Staphylococci species or Enterococcus faecalis was associated with pathological low counts of live spermatozoa (p < 0.05). In multivariate analysis only Enterococcus faecalis showed a significant impact on sperm concentration (OR 4.48; 95% CI 1.06-22.10; p = 0.041). CONCLUSIONS: Asymptomatic bacteriospermia has always been a subject of great controversy. There is still an ongoing debate whether to treat or not to treat. Here, we demonstrate that asymptomatic bacteriospermia is clearly associated with impaired semen quality. Our findings speak in favour of strain-specific interactions with semen parameters. Especially Enterococcus faecalis seriously affects sperm concentration.

Effects of common Gram-negative pathogens causing male genitourinary-tract infections on human sperm functions.

Male genitourinary tract (MGT) bacterial infections are considered responsible for 15% of male infertility, but the mechanisms underlying decreased semen quality are poorly known. We evaluated in vitro the effect of strains of Gram-negative uropathogenic species (two E.coli strains, three K. pneumoniae strains, P. aeruginosa and E. cloacae) on motility, viability, mitochondrial oxidative status, DNA fragmentation and caspase activity of human spermatozoa. All strains, except P. aeruginosa, reduced significantly sperm motility, with variable effects. Sperm Immobilizing Factor (SIF) was largely responsible for deteriorating effects on sperm motility of E. coli strains since they were completely reverted by knockout of SIF coding recX gene. Sequence alignment for RecX showed the presence of high homologous sequences in K. pneumoniae and E. cloacae but not in P. aeruginosa. These results suggest that, in addition to E.coli, other common uropathogenic Gram-negative bacteria affect sperm motility through RecX products. In addition to sperm motility, the E. coli strain ATCC 35218 also affected sperm viability, and induced caspase activity, oxidative stress and DNA fragmentation suggesting an interspecies variability in the amount and/or type of the produced spermatotoxic factors. In general, our results highlight the need for a careful evaluation of semen infections in the diagnostic process of the infertile man.

Assessing the testicular sperm microbiome: a low-biomass site with abundant contamination.

RESEARCH QUESTION: The semen harbours a diverse range of microorganisms. The origin of the seminal microbes, however, has not yet been established. Do testicular spermatozoa harbour microbes and could they potentially contribute to the seminal microbiome composition? DESIGN: The study included 24 samples, comprising a total of 307 testicular maturing spermatozoa. A high-throughput sequencing method targeting V3 and V4 regions of 16S rRNA gene was applied. A series of negative controls together with stringent in-silico decontamination methods were analysed. RESULTS: Between 50 and 70% of all the detected bacterial reads accounted for contamination in the testicular sperm samples. After stringent decontamination, Blautia (P = 0.04), Cellulosibacter (P = 0.02), Clostridium XIVa (P = 0.01), Clostridium XIVb (P = 0.04), Clostridium XVIII (P = 0.02), Collinsella (P = 0.005), Prevotella (P = 0.04), Prolixibacter (P = 0.02), Robinsoniella (P = 0.04), and Wandonia (P = 0.04) genera demonstrated statistically significant abundance among immature spermatozoa. CONCLUSIONS: Our results indicate that the human testicle harbours potential bacterial signature, though in a low-biomass, and could contribute to the seminal microbiome composition. Further, applying stringent decontamination methods is crucial for analysing microbiome in low-biomass site.

Results from a large cross-sectional study assessing Chlamydia trachomatis, Ureaplasma spp. and Mycoplasma hominis urogenital infections in patients with primary infertility.

Female and male infertility have been associated to Chlamydia trachomatis, Ureaplasma spp. and Mycoplasma hominis urogenital infections. However, evidence from large studies assessing their prevalence and putative associations in patients with infertility is still scarce. The study design was a cross-sectional study including 5464 patients with a recent diagnosis of couple's primary infertility and 404 healthy control individuals from Cordoba, Argentina. Overall, the prevalence of C. trachomatis, Ureaplasma spp. and M. hominis urogenital infection was significantly higher in patients than in control individuals (5.3%, 22.8% and 7.4% vs. 2.0%, 17.8% and 1.7%, respectively). C. trachomatis and M. hominis infections were significantly more prevalent in male patients whereas Ureaplasma spp. and M. hominis infections were more prevalent in female patients. Of clinical importance, C. trachomatis and Ureaplasma spp. infections were significantly higher in patients younger than 25 years. Moreover, Ureaplasma spp. and M. hominis infections were associated to each other in either female or male patients being reciprocal risk factors of their co-infection. Our data revealed that C. trachomatis, Ureaplasma spp. and M. hominis are prevalent uropathogens in patients with couple's primary infertility. These results highlight the importance of including the screening of urogenital infections in the diagnostic workup of infertility.

Sexually transmitted infections and semen quality from subfertile men with and without leukocytospermia.

BACKGROUND: The role of sexually transmitted infections (STIs) in semen parameters and male infertility is still a controversial area. Previous studies have found bacterial infection in a minority of infertile leukocytospermic males. This study aims to investigate the prevalence of STIs in semen from subfertile men with leukocytospermia (LCS) and without leukocytospermia (non-LCS) and their associations with sperm quality. METHODS: Semen samples were collected from 195 men who asked for a fertility evaluation. Infection with the above 6 pathogens was assessed in each sample. Sperm quality was compared in subfertile men with and without LCS. RESULTS: The LCS group had significantly decreased semen volume, sperm concentration, progressive motility, total motility and normal morphology. The infection rates of Ureaplasma urealyticum (Uuu), Ureaplasma parvum (Uup), Mycoplasma hominis (MH), Mycoplasma genitalium (MG), Chlamydia trachomatis (CT), herpes simplex virus-2 (HSV-2) and Neisseria gonorrhoeae (NG) were 8.7 %, 21.0 %, 8.2 %, 2.1 %, 3.6 %, 1.0 and 0 %, respectively. The STI detection rates of patients with LCS were higher than those of the non-LCS group (52.3 % vs. 39.3 %), although there was no statistically significant difference between the two groups (P = 0.07). All semen parameters were not significantly different between LCS with STIs and without STIs, except the semen volume in the MG-infected patients with LCS was significantly lower than that in the noninfected group. CONCLUSIONS: LCS was associated with a reduction in semen quality, but was not associated with STIs.

Abundance and Seasonality of Aedes aegypti (Diptera: Culicidae) in Two Suburban Localities of South Mexico, With Implications for Wolbachia (Rickettsiales: Rickettsiaceae)-Carrying Male Releases for Population Suppression.

We conducted a baseline characterization of the abundance and seasonality of Aedes aegypti (Linnaeus, 1762)-a vector of dengue, chikungunya, and Zika-in two suburban localities of Yucatan, Mexico, as the first step in the implementation of an integrated vector management (IVM) plan combining 'traditional Aedes control' (source reduction/truck-mounted ultra-low volume [ULV] spraying) and incompatible insect technique/sterile insect technique for population suppression in Yucatan, Mexico. Weekly entomological collections with ovitraps and BG-sentinel traps were performed in 1-ha quadrants of both localities for 1 yr. Three distinct periods/phases were identified, closely associated with precipitation: 1) a phase of low population abundance during the dry season (weekly average of Aedes eggs per ovitrap and adults per BG trap = 15.51 ± 0.71 and 10.07 ± 0.88, respectively); 2) a phase of population growth and greatest abundance of Aedes (49.03 ± 1.48 eggs and 25.69 ± 1.31 adults) during the rainy season; and finally 3) a phase of decline among populations (20.91 ± 0.97 eggs and 3.24 ± 0.21 adults) after the peak of the rainy season. Seasonal abundance and dynamics of Ae. aegypti populations suggest that it is feasible to develop and implement time-specific actions as part of an IVM approach incorporating integrating novel technologies (such as rear-and-release of Wolbachia-infected males) with classic (insecticide-based) approaches implemented routinely for vector control. In agreement with the local vector control program, we propose a pilot IVM strategy structured in a preparation phase, an attack phase with traditional vector control, and a suppression phase with inundative releases, which are described in this paper.

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.