Mycoplasma genitalium incidence, treatment failure, and resistance: a retrospective survey of men of infertile couples from a hospital in China

Genital mycoplasma infection: a systematic review and meta-analysis

BACKGROUND

Recent studies have suggested that genital mycoplasma infections may be associated with male infertility. However, this association remains controversial due to time lapse, sample size, and regional prevalence.

OBJECTIVES

This study aimed to systematically evaluate the relationship between genital mycoplasma and male infertility through a meta-analysis and to provide a basis for the clinical management of male infertility.

METHODS

We conducted a search on PubMed, EMBASE, the Cochrane Library, and CNKI databases, from January 2000 to June 2023 to identify case-control studies on the interrelationship between genital mycoplasma infection and male infertility. Two independent researchers performed an assessment of the methodological quality of trials according to the Newcastle-Ottawa scale and extracted data strictly based on the inclusion and exclusion criteria, and afterward, we carried out a meta-analysis using Stata 16.0. Pooled odds ratios (OR) with 95% confidence intervals (CI) were used to assess this relationship.

RESULTS

This meta-analysis included 21 studies from seven countries with a total of 53025 infertility cases and 6435 controls; the age range of the participating men was from 20 to 59 years old. The results obtained showed a higher prevalence of M. genitalium, M. hominis and U. urealyticum infections in infertile men than in the controls, with the opposite result for U. parvum (M. genitalium, OR, 3.438 [95% CI: 1.780, 6.643], with P = 0.000; M. hominis, OR, 1.840 [95% CI: 1.013, 3.343], with P = 0.045; U. urealyticum, OR, 3.278 [95% CI: 2.075, 5.180], with P = 0.000; U. parvum, OR, 1.671 [95% CI: 0.947, 2.950], with P = 0.077). Further, two subgroup analyses also showed that M. hominis and U. urealyticum infections were strongly associated with male infertility in China (M. hominis, P = 0.009; U. urealyticum, P = 0.000); however, M. hominis and U. urealyticum infection was not strongly associated with male infertility worldwide (M. hominis, P = 0.553; U. urealyticum, P = 0.050).

CONCLUSION

This meta-analysis revealed that male infertility was significantly associated with M. genitalium, M. hominis and U. urealyticum infections, while U. parvum infection was not. Further, our study showed that genital mycoplasma infection influences male infertility and provides a basis for future treatment.

Emerging multidrug resistance contributes to treatment failure in Mycoplasma genitalium infected patients in China

The increased treatment failure in patients with sexually transmitted Mycoplasma genitalium infection is associated with antimicrobial resistance. We performed a retrospective survey of antimicrobial clinical outcomes in M. genitalium-infected patients. In addition, we detected macrolide, fluoroquinolone and tetracycline resistance-associated markers to determine their role in treatment failure. The overall incidence of treatment failure was 28.29%, regardless of the drug used. In the present study, the prevalence of macrolide resistance-associated mutations in the 23S rRNA gene was 64%; that of fluroquinolone resistance-associated S83/D87 substitutions in the parC gene was 67.5%; and that of the tetracycline resistance-associated C1192T mutation in the 16S rRNA gene was 22.5%. Furthermore, evidence of dual antimicrobial resistance was found in 46.4% of pretreatment samples, and triple antimicrobial resistance was identified in 9.9%. These findings regarding the emergence of multidrug-resistant strains of M. genitalium in China are concerning and emphasize the importance of guiding M. genitalium treatment with antimicrobial resistance assays.

Low prevalence of macrolide resistance in Mycoplasma genitalium infections in a cohort of pregnant women living with human immunodeficiency virus

OBJECTIVE

Macrolide resistance in Mycoplasma genitalium (M. genitalium) is increasing as a result of the widespread use of azithromycin in the treatment of sexually transmitted infections (STIs). To date, there are few published studies on macrolide resistance patterns in South African pregnant women. This study now contributes to the growing body of knowledge.

METHODS

This study included 385 pregnant women living with HIV. Vaginal swabs were collected from consenting pregnant women and used for the detection of M. genitalium using the TaqMan assay. Macrolide resistance-associated mutations in the 23S rRNA gene were determined for all samples that tested positive for M. genitalium using the Allplex^TM MG & AziR assay (Seegene) which allows for the simultaneous detection and identification of M. genitalium and six mutations (A2058C, A2058G, A2058T, A2059C, A2059G and A2059T) responsible for azithromycin resistance. The correlation between the TaqMan assay and Allplex^TM MG & AziR assay (Seegene) for the detection of M. genitalium was also performed in a subset of 121 samples.

RESULTS

Of the 385 samples tested in this study, 14 samples were positive for M. genitalium estimating a prevalence of 3.6%. The same 14 samples also tested positive on the Allplex^TM assay indicating a good correlation between the TaqMan Assay and the Allplex^TM. Of the 14 positive samples, one sample carried a mutation at position A2059G denoting macrolide resistance in this pathogen. Mutations in the other regions of the 23S rRNA were not detected. All assay controls used in the mutation scanning produced the desired results showing the validity of the assay.

CONCLUSION

In this study, macrolide resistance in M. genitalium was detected. Despite the low prevalence of resistance determinants ongoing antimicrobial resistance surveillance is vital considering that azithromycin is used in the syndromic management for the treatment of vaginal discharge syndrome.

Defensins: defenders of human reproductive health

BACKGROUND

Reproductive tract infection is an important factor leading to male and female infertility. Among female infertility factors, microbial and viral infections are the main factors affecting female reproductive health and causing tubal infertility, ectopic tubal pregnancy and premature delivery. Among male infertility factors, 13-15% of male infertility is related to infection. Defensins are cationic antibacterial and antiviral peptides, classified into α-defensins, β-defensins and θ-defensins. Humans only have α-defensins and β-defensins. Apart from their direct antimicrobial functions, defensins have an immunomodulatory function and are involved in many physiological processes. Studies have shown that defensins are widely distributed in the female reproductive tract (FRT) and male reproductive tract (MRT), playing a dual role of host defence and fertility protection. However, to our knowledge, the distribution, regulation and function of defensins in the reproductive tract and their relation to reproduction have not been reviewed.

OBJECTIVE AND RATIONALE

This review summarizes the expression, distribution and regulation of defensins in the reproductive tracts to reveal the updated research on the dual role of defensins in host defence and the protection of fertility.

SEARCH METHODS

A systematic search was conducted in PubMed using the related keywords through April 2022. Related data from original researches and reviews were integrated to comprehensively review the current findings and understanding of defensins in the human reproductive system. Meanwhile, female and male transcriptome data in the GEO database were screened to analyze defensins in the human reproductive tracts.

OUTCOMES

Two transcriptome databases from the GEO database (GSE7307 and GSE150852) combined with existing researches reveal the expression levels and role of the defensins in the reproductive tracts. In the FRT, a high expression level of α-defensin is found, and the expression levels of defensins in the vulva and vagina are higher than those in other organs. The expression of defensins in the endometrium varies with menstrual cycle stages and with microbial invasion. Defensins also participate in the local immune response to regulate the risk of spontaneous preterm birth. In the MRT, a high expression level of β-defensins is also found. It is mainly highly expressed in the epididymal caput and corpus, indicating that defensins play an important role in sperm maturation. The expression of defensins in the MRT varies with androgen levels, age and the status of microbial invasion. They protect the male reproductive system from bacterial infections by neutralizing lipopolysaccharide and downregulating pro-inflammatory cytokines. In addition, animal and clinical studies have shown that defensins play an important role in sperm maturation, motility and fertilization.

WIDER IMPLICATIONS

As a broad-spectrum antimicrobial peptide without drug resistance, defensin has great potential for developing new natural antimicrobial treatments for reproductive tract infections. However, increasing evidence has shown that defensins can not only inhibit microbial invasion but can also promote the invasion and adhesion of some microorganisms in certain biological environments, such as human immunodeficiency virus. Therefore, the safety of defensins as reproductive tract anti-infective drugs needs more in-depth research. In addition, the modulatory role of defensins in fertility requires more in-depth research since the current conclusions are based on small-size samples. At present, scientists have made many attempts at the clinical transformation of defensins. However, defensins have problems such as poor stability, low bioavailability and difficulties in their synthesis. Therefore, the production of safe, effective and low-cost drugs remains a challenge.

Molecular epidemiology and antimicrobials resistance mechanism of Mycoplasma genitlaium

Currently, infections caused by Mycoplasma genitalium are ones the most common sexually transmitted infections. Their prevalence is varied from 1.3% to 15.9%. Infections caused by M.genitalium may lead to urethritis in men and a wide spectrum of diseases in women. Antibiotic resistance now is one of the most emerging problems both in the scientific and in the healthcare fields. The usage of antimicrobials inhibiting cell wall synthesis for the treatment of M.genitalium is ineffective, and resistance to macrolides and fluoroquinolones is increasing rapidly. M.genitalium infections diagnostics is complicated due to specific conditions and duration of culture methods. The usage of nucleic acid amplification techniques is the most relevant for laboratory diagnostics, and is used in existing assays. This review compiles current data on the prevalence, molecular mechanisms of pathogenesis and antibiotic resistance, as well as diagnostics methods of M.genitalium.

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.

Macrolide and fluoroquinolone associated mutations in Mycoplasma genitalium in a retrospective study of male and female patients seeking care at a STI Clinic in Guangzhou, China, 2016-2018

Background

Antimicrobial resistance in M. genitalium is a growing clinical problem. We investigated the mutations associated with macrolide and fluoroquinolone resistance, two commonly used medical regimens for treatment in China. Our aim is to analyze the prevalence and diversity of mutations among M. genitalium-positive clinical specimens in Guangzhou, south China.

Methods

A total of 154 stored M. genitalium positive specimens from men and women attending a STI clinic were tested for macrolide and fluoroquinolone mutations. M. genitalium was detected via TaqMan MGB real-time PCR. Mutations associated with macrolide resistance were detected using primers targeting region V of the 23S rRNA gene. Fluoroquinolone resistant mutations were screened via primers targeting topoisomerase IV (parC) and DNA gyrase (gyrA).

Results

98.7% (152/154), 95.5% (147/154) and 90.3% (139/154) of M. genitalium positive samples produced sufficient amplicon for detecting resistance mutations in 23S rRNA, gyrA and parC genes, respectively. 66.4% (101/152), 0.7% (1/147) and 77.7% (108/139) samples manifested mutations in 23S rRNA, gyrA and parC genes, respectively. A2072G (59/101, 58.4%) and S83I (79/108, 73.1%) were highly predominating in 23S rRNA and parC genes, respectively. Two samples had amino acid substitutions in gyrA (M95I and A96T, respectively). Two samples had two amino acid substitutions in parC (S83I + D87Y). 48.6% (67/138) of samples harbored both macrolide and fluoroquinolone resistance-associated mutations. The most common combination of mutations was A2072G (23S rRNA) and S83I (parC) (40/67, 59.7%). One sample had three amino acid changes in 23S rRNA, gyrA and parC genes (A2072G + A96T + S83I).

Conclusions

The high antimicrobial resistance rate of M. genitalium in Guangzhou is a very worrying problem and suggests that antimicrobial resistance testing and the development of new antibiotic regimens are crucially needed.