Detection ofChlamydia trachomatis,Ureaplasma urealyticumandMycoplasma hominisin infertile Bulgarian men with multiplex real-time polymerase chain reaction

Are sexually transmitted infections associated with male infertility? A systematic review and in-depth evaluation of the evidence and mechanisms of action of 11 pathogens

Purpose

To systematically review the evidence on the association between sexually transmitted infections (STIs) and male infertility. We sought to answer two questions: Are STIs significantly associated with detrimental changes in semen parameters?; and, is the prevalence of STIs significantly higher in infertile than fertile men?

Materials and methods

PubMed, Scopus and Google Scholar databases were searched (inceptionMarch 2023) following the PRISMA guidelines. Identified original studies in English on the association between STIs and male infertility were included. Data was tabulated/described by pathogen, mechanisms of action, number of studies and their level of evidence.

Results

Seventy out of 903 originally retrieved articles were included in this review. For the detrimental changes in semen parameters (first question), the evidence seems equivocal based on the nearly equal number of studies and similar levels of evidence. The only exception was for Ureaplasma, where the number of studies and levels of evidence supported an association with male infertility. Pertaining to a significantly higher prevalence of STI among infertile compared to fertile men (second question), evidence was insufficient to support/deny a significant association. The two exceptions were Ureaplasma and Mycoplasma, where the number of studies and evidence levels were in favour of an association with male infertility.

Conclusions

Generally, the relationship between STIs and male infertility remains to be uncovered. Our appraisal of the overall state of this relationship shows that the evidence base leaves much to be desired. The exceptions are Ureaplasma and Mycoplasma, where the evidence convincingly suggests their associations with infertility in men.

Analysis of Ureaplasma urealyticum, Chlamydia trachomatis, Mycoplasma genitalium and Neisseria gonorrhoeae infections among obstetrics and gynecological outpatients in southwest China: a retrospective study

Background

The aim of this study was to analyze the present situation of Ureaplasma urealyticum (UU), Chlamydia trachomatis (CT), Mycoplasma genitalium (MG) and Neisseria gonorrhoeae (NG) infections among obstetrics and gynecological outpatients in southwest China.

Methods

A total of 3225 urogenital swabs were included in this study. All swabs were tested by RNA-based simultaneous amplification and testing (SAT) methods. Routine analysis of leucorrhea smear and drug susceptibility were performed in UU positive patients.

Results

Of these 3225 outpatients, the positive rate was 27.07% for UU, 4.99% for CT, 3.10% for MG, and 0.09% for NG. UU, CT, and MG infections were more common in women of reproductive age (aged 25–34 years), while NG infection was more prominent in women aged 30–34 years and over 40 years. Overall, the infection rate of UU was significantly higher than that of the other three infections, and UU also played a major role even in the mixed infections. 65.07% of the UU positive patients had negative results on routine leucorrhea smear analysis, and the remaining patients may have bacterial vaginitis (15.79%), fungal vaginitis (11.48%), trichomonas vaginitis (0.96%) or other vaginal inflammation (6.70%). We have observed that maternal UU infection can lead to low birth weight, neonatal pneumonia, and premature delivery. The results of the drug susceptibility test of UU showed a higher sensitivity to pristinamycin, doxycycline, tetracycline, clarithromycin, and josamycin (100%, 97.0%, 96.4%, 95.9%, and 95.3%, respectively), and lower sensitivity to ciprofloxacin and ofloxacin (2.4% and 4.7% respectively).

Conclusions

This study could contribute to a better understanding of the current epidemiological features of UU, CT, MG, and NG among obstetrics and gynecological outpatients in southwest China, and thus facilitate to development of the more effective intervention, prevention, and treatment of reproductive tract infection.

Oxidative Stress, Testicular Inflammatory Pathways, and Male Reproduction

Inflammation is among the core causatives of male infertility. Despite male infertility being a serious global issue, "bits and pieces" of its complex etiopathology still remain missing. During inflammation, levels of proinflammatory mediators in the male reproductive tract are greater than usual. According to epidemiological research, in numerous cases of male infertility, patients suffer from acute or chronic inflammation of the genitourinary tract which typically occurs without symptoms. Inflammatory responses in the male genital system are inextricably linked to oxidative stress (OS). OS is detrimental to male fertility parameters as it causes oxidative damage to reproductive cells and intracellular components. Multifarious male infertility causative factors pave the way for impairing male reproductive functions via the common mechanisms of OS and inflammation, both of which are interlinked pathophysiological processes, and the occurrence of any one of them induces the other. Both processes may be simultaneously found in the pathogenesis of male infertility. Thus, the present article aims to explain the role of inflammation and OS in male infertility in detail, as well as to show the mechanistic pathways that link causative factors of male reproductive tract inflammation, OS induction, and oxidant-sensitive cellular cascades leading to male infertility.

The silent presence of Mycoplasma hominis in patients with prostate cancer

BACKGROUND

Mycoplasma hominis, an opportunistic pathogen in human genitourinary tract, can cause chronic infection in the prostate. Intracellular survival of M. hominis leads to a prolonged presence in the host cells that can affect the cell's biological cycle. In the present study, we aimed to evaluate the frequency of M. hominis DNA in prostate tissue of Iranian patients with prostate cancer (PCa) in comparison to a control group with benign prostatic hyperplasia (BPH).

METHODS

This research was a retrospective case-control study using 61 archived formalin-fixed paraffin-embedded (FFPE) blocks of prostate tissue from patients with PCa and 70 FFPE blocks of patients with BPH. Real-time PCR, targeting two different genes, 16S rRNA and yidC, in the M. hominis genome was performed for all specimens.

RESULTS

Out of 61 blocks of prostate biopsy from patients with PCa, eight samples (13%) were positive for M. hominis, while the bacterium was not detected in any of the 70 blocks of patients with BPH (P value, 0.002).

CONCLUSIONS

The high frequency of M. hominis in patients with PCa likely shows a hidden role of the organism in prostate cancer during its chronic, apparently silent and asymptomatic colonization in prostate.

Bacterial infection of the male reproductive system causing infertility

Bacterial infections play a disruptive and hidden role in male reproductive failure. Different kinds of bacteria are often able to interfere with reproductive function in both sexes and lead to infertility. In this study, to further evaluate the role of bacterial infections in male reproduction we provided an extensive overview of so far researches investigating the effects of bacterial infections on male fertility. We searched Medline, PubMed, Scopus and Google scholar databases to identify the potentially relevant studies on bacterial infections and their implications in male infertility. All the bacteria included in this article have negative effects on the male reproductive function; however, there is ample evidence to blame bacteria such as Escherichia coli, Chlamydia trachomatis, Ureaplasma, Mycoplasma and Staphylococcus aureus for reduced fertility and deterioration of sperm parameters. More studies are needed to clarify the molecular mechanisms by which different bacteria exert their detrimental effects on male reproductive system. Getting more insight into probable mechanisms, would significantly facilitate the production of new, advanced, and effective remedies in the future. In view of all evidence, we strongly suggest increasing awareness among people and considering screening programs for patients seeking fertility both to avoid transmission and to improve fertility outcomes among them.

Genetic Passive Immunization with Adenoviral Vector Expressing Chimeric Nanobody-Fc Molecules as Therapy for Genital Infection Caused by Mycoplasma hominis

Developing pathogen-specific recombinant antibody fragments (especially nanobodies) is a very promising strategy for the treatment of infectious disease. Nanobodies have great potential for gene therapy application due to their single-gene nature. Historically, Mycoplasma hominis has not been considered pathogenic bacteria due to the lack of acute infection and partially due to multiple studies demonstrating high frequency of isolation of M. hominis samples from asymptomatic patients. However, recent studies on the role of latent M. hominis infection in oncologic transformation, especially prostate cancer, and reports that M. hominis infects Trichomonas and confers antibiotic resistance to Trichomonas, have generated new interest in this field. In the present study we have generated specific nanobody against M. hominis (aMh), for which the identified target is the ABC-transporter substrate-binding protein. aMh exhibits specific antibacterial action against M. hominis. In an attempt to improve the therapeutic properties, we have developed the adenoviral vector-based gene therapy approach for passive immunization with nanobodies against M. hominis. For better penetration into the mucous layer of the genital tract, we fused aMh with the Fc-fragment of IgG. Application of this comprehensive approach with a single systemic administration of recombinant adenovirus expressing aMh-Fc demonstrated both prophylactic and therapeutic effects in a mouse model of genital M. hominis infection.

High dynamic range detection of Chlamydia trachomatis growth by direct quantitative PCR of the infected cells

Chlamydiae are obligate intracellular bacteria developing in an intracytoplasmic niche, the inclusion. Chlamydia growth measurement by inclusion counting is a key task in the development of novel antichlamydial antibiotics and in vaccine studies. Most of the current counting methods rely on the immunofluorescent staining of the inclusions and either manual or automatic microscopy detection and enumeration. The manual method is highly labor intensive, while the automatic methods are either medium-throughput or require automatic microscopy. The sensitive and specific PCR technology could be an effective method for growth related chlamydial DNA detection; however the currently described PCR approaches have a major limitation, the requirement of purification of DNA or RNA from the infected cells. This limitation makes this approach unfeasible for high-throughput screenings. To overcome this, we developed a quantitative PCR (qPCR) method for the detection of Chlamydia trachomatis DNA directly from the infected HeLa cells. With our method we were able to detect the bacterial growth in a 4 log scale (multiplicity of infection (MOI): 64 to 0.0039), with high correlation between the biological and technical replicates. As a further proof of the method, we applied the direct qPCR for antibiotic minimum inhibitory concentration (MIC) measurements. The measured MICs of moxifloxacin, tetracycline, clarithromycin and compound PCC00213 were 0.031 μg/ml, 0.031 μg/ml, 0.0039 μg/ml and 6.2 μg/ml respectively, identical or close to the already published MIC values. Our direct qPCR method for chlamydial growth and antibiotic MIC determination is less time-consuming, more objective and more sensitive than the currently applied manual or automatic fluorescent microscopy- based methods.