The use of enzyme-linked immunosorbent assay for detection of Mycoplasma hominis antibodies in infertile women serum samples

Mycoplasma genitalium infection in the female reproductive system: Diseases and treatment

Mycoplasma genitalium is a newly emerged sexually transmitted disease pathogen and an independent risk factor for female cervicitis and pelvic inflammatory disease. The clinical symptoms caused by M. genitalium infection are mild and easily ignored. If left untreated, M. genitalium can grow along the reproductive tract and cause salpingitis, leading to infertility and ectopic pregnancy. Additionally, M. genitalium infection in late pregnancy can increase the incidence of preterm birth. M. genitalium infections are often accompanied by co-infection with other sexually transmitted pathogens (Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis) and viral infections (Human Papilloma Virus and Human Immunodeficiency Virus). A recent study suggested that M. genitalium plays a role in tumor development in the female reproductive system. However, few studies endorsed this finding. In recent years, M. genitalium has evolved into a new "superbug" due to the emergence of macrolide-and fluoroquinolone-resistant strains leading to frequent therapy failures. This review summarizes the pathogenic characteristics of M. genitalium and the female reproductive diseases caused by M. genitalium (cervicitis, pelvic inflammatory disease, ectopic pregnancy, infertility, premature birth, co-infection, reproductive tumors, etc.), as well as its potential relationship with reproductive tumors and clinical treatment.

Sexually transmitted diseases and infertility

Female infertility, including tubal factor infertility, is a major public health concern worldwide. Most cases of tubal factor infertility are attributable to untreated sexually transmitted diseases that ascend along the reproductive tract and are capable of causing tubal inflammation, damage, and scarring. Evidence has consistently demonstrated the effects of Chlamydia trachomatis and Neisseria gonorrhoeae as pathogenic bacteria involved in reproductive tract morbidities including tubal factor infertility and pelvic inflammatory disease. There is limited evidence in the medical literature that other sexually transmitted organisms, including Mycoplasma genitalium, Trichomonas vaginalis, and other microorganisms within the vaginal microbiome, may be important factors involved in the pathology of infertility. Further investigation into the vaginal microbiome and other potential pathogens is necessary to identify preventable causes of tubal factor infertility. Improved clinical screening and prevention of ascending infection may provide a solution to the persistent burden of infertility.

Ureaplasma urealyticum: Presence among Sexually Transmitted Diseases

The aim of this study was to detect the presence of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Mycoplasma hominis, Trichomonas vaginalis, and Ureaplasma urealyticum in genital specimens of symptomatic patients. This study also examined the role of U. urealyticum in infections of the lower genital tract. Cervical and urethral samples from 96 patients (46 males, 50 females) were tested using the Seeplex(^®) STD6 ACE kit. Consent forms were received and a questionnaire was applied. All statistical analyses were performed using the SPSS statistical software program (version 17.0). Among the samples tested, at least 1 pathogen was detected in 49% of the samples; specifically, the rate of detection of U. urealyticum, M. hominis, C. trachomatis, N. gonorrhoeae, M. genitalium, and T. vaginalis was 29.1%, 10.4%, 8.3%, 7.3%, 6.3%, and 4.2%, respectively. U. urealyticum was detected as the sole pathogen in samples from 10% of female patients and 28.3% of male patients (p = 0.035). U. urealyticum was present in 54.5% (18/33) of samples in which a single pathogen was detected and 71.4% (10/14) of samples in which multiple pathogens were detected. Among men, significant differences in discharge, dysuria, and pruritus were not noted among those with negative results (84.6%, 69.2%, and 38.5%, respectively), among those positive for only U. urealyticum (100%, 66.7%, and 26.7%, respectively), and those positive for N. gonorrhoeae, C. trachomatis, M. genitalium, and T. vaginalis (100%, 93.3%, and 26.7%, respectively). Detection of U. urealyticum, either alone or together with other pathogens, in a symptomatic group of patients is an important finding, particularly in men.

Association of Mycoplasma genitalium with infertility in North Indian women

OBJECTIVES

Data regarding the association of Mycoplasma genitalium with infertility is scarce. This study was planned to look for the presence and association of M. genitalium in women with infertility.

MATERIALS AND METHODS

A prospective observational study was conducted on 100 cases of infertile women. The control group included 100 healthy fertile women. Samples of first void urine (FVU), endocervical swabs (ECS), and endometrial biopsies were subjected to polymerase chain reaction targeting MgPa gene to look for the presence of M. genitalium DNA. All endometrial biopsy samples were subjected to histopathological examination. A detailed clinical history of patients was taken, and all relevant investigations were recorded.

RESULTS

M. genitalium was found in 16% of women with infertility from either of the samples that is, FVU and/or ECS and/or endometrium biopsy, and none from controls. ECS and biopsy could detect the highest number of cases (27%). Asymptomatic cases predominated in the study and M. genitalium positivity (73.3%) was seen more in primary infertility. Tubal occlusion and disordered proliferative endometrium were demonstrated in 33% and 26.66% of M. genitalium positive cases respectively.

CONCLUSIONS

The study shows an association of M. genitalium infection and infertility and suggests routine screening of this pathogen in patients with infertility.

Chlamydia trachomatis and Genital Mycoplasmas: Pathogens with an Impact on Human Reproductive Health

The most prevalent, curable sexually important diseases are those caused by Chlamydia trachomatis (C. trachomatis) and genital mycoplasmas. An important characteristic of these infections is their ability to cause long-term sequels in upper genital tract, thus potentially affecting the reproductive health in both sexes. Pelvic inflammatory disease (PID), tubal factor infertility (TFI), and ectopic pregnancy (EP) are well documented complications of C. trachomatis infection in women. The role of genital mycoplasmas in development of PID, TFI, and EP requires further evaluation, but growing evidence supports a significant role for these in the pathogenesis of chorioamnionitis, premature membrane rupture, and preterm labor in pregnant woman. Both C. trachomatis and genital mycoplasmas can affect the quality of sperm and possibly influence the fertility of men. For the purpose of this paper, basic, epidemiologic, clinical, therapeutic, and public health issue of these infections were reviewed and discussed, focusing on their impact on human reproductive health.

Preparation of reference stocks suitable for evaluation of alternative NAT-based mycoplasma detection methods

AIMS

The aim of this study was to optimize conditions for preparation and cryopreservation of mycoplasma reference materials suitable to evaluate alternative nucleic acid testing (NAT)-based assays and to compare their limits of detection (LODs) with those of conventional culture-based methods.

METHODS AND RESULTS

Acholeplasma laidlawii, Mycoplasma gallisepticum and Mycoplasma arginini stocks with low ratios of genomic copies to colony forming units (12, 8 and 4, respectively) harvested in early stationary phases of growth were preserved with different cryoprotective agents (CPAs) under slow (1°C min(-1)), moderate (8°C min(-1)), fast (13°C min(-1)) and 'snapshot' (60°C min(-1)) cooling rates. Depending on mycoplasma species, increasing the cooling rate from slow to snapshot enhanced cell survival up to 5-fold. The addition of 10% (v/v) dimethyl sulfoxide (DMSO) and 15% (v/v) glycerol significantly improved cell survival of all tested strains. Cryoprotected stocks maintained high and stable titres for at least 1 year during storage at -80°C. Sonication of cell cultures prior to cryopreservation enhanced cell dispersion and reduced of GC/CFU ratios.

CONCLUSIONS

It is feasible to prepare stable reference stocks of cryopreserved mycoplasma cells suitable to reliably compare NAT- and culture-based mycoplasma testing methods.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study describes experimental results demonstrating the preparation and storage of highly viable and dispersed mycoplasma reference stocks suitable for comparing alternative NAT-and conventional culture-based mycoplasma detection methods.

Validation of nested PCR and a selective biochemical method as alternatives for mycoplasma detection

Direct culture is the most common way to reliably detect mycoplasma, but it is not practical for the qualitative control of cell therapeutics because of the elaborate culture medium, the prolonged incubation time, and the large sample volumes. Here, we chose two alternative methods using commercial detection kits, the PCR mycoplasma detection kit with nested PCR and the selective biochemical method, MycoAlert(®), and validated them with the direct culture method as a reference. We tested eight mycoplasma species and five validation parameters: specificity, detection limit, robustness, repeatability, and ruggedness, based on the regulatory guidelines in the US Pharmacopoeia. All experiments were performed using fibroblasts spiked with mycoplasma. Specificity tests for both methods included all mycoplasma species, except Mycoplasma pneumonia and M. genitalium for the nested PCR and Ureaplasma urealyticum for the MycoAlert(®) assay. Regarding the detection limit, the nested PCR proved to be as sensitive as the direct culture method and more sensitive than the MycoAlert(®) assay. The predicted median for probit = 0.9 was 54 (44-76) CFU/ml for M. hyorhinis and 16 (13-23) CFU/ml for M. hominis by the nested PCR, but 431 (346-593) CFU/ml and 105 (87-142) CFU/ml, respectively, with MycoAlert(®). Changes in the concentration of reagents, reagent lot, or individual analysts did not influence the results of the examined methods. The results of this study support nested PCR as a valuable alternative for mycoplasma detection.

Genetic polymorphism in an inflammasome component, cervical mycoplasma detection and female infertility in women undergoing in vitro fertilization

The inflammasome is an inducible cytoplasmic structure that is responsible for production and release of biologically active interleukin-1 (IL-1). A polymorphism in the inflammasome component NALP3 has been associated with decreased IL-1 levels and increased occurrence of vaginal Candida infection. We hypothesized that this polymorphism-induced variation would influence susceptibility to infertility. DNA was obtained from 243 women who were undergoing in vitro fertilization (IVF) and tested for a length polymorphism in intron 2 of the gene coding for NALP3 (gene symbol CIAS1). At the conclusion of testing the findings were analyzed in relation to clinical parameters and IVF outcome. The frequency of the 12unit repeat allele, associated with maximal inflammasome activity, was 62.3% in cases of female infertility vs. 75.6% in cases where only the male partner had a detectable fertility problem (p=0.0095). Conversely, the frequency of the 7unit repeat allele was 28.9% in those with a female fertility problem, 17.0% in women with infertile males and 18.4% in idiopathic infertility (p=0.0124). Among the women who were cervical culture-positive for mycoplasma the frequency of the 7unit repeat was 53.7% as opposed to 19.5% in those negative for this infection (p<0.0001). We conclude that the CIAS1 7unit repeat polymorphism increases the likelihood of mycoplasma infection-associated female infertility.

The antibody against a nuclear autoantigenic sperm protein can result in reproductive failure

To study whether the antibody against the testis form of the nuclear autoantigenic sperm protein (tNASP) could result in reproductive failure, we successfully cloned and expressed a 339-bp cDNA fragment of mouse tNASP (mtNASP). Using mouse as a model, recombinant mtNASP (rmtNASP) and a synthetic peptide, human tNASP(393-408) (htNASP(393-408)), were investigated for their antifertility effect. Active immunization with rmtNASP or the synthesized peptide raised high antibody titers in the immunized mice. Sperm-egg binding and fusion assay were carried out in 8-10-week-old BALB/c mice. Sperm-egg binding and in vitro fertilization of mouse oocytes were inhibited by co-incubation of zona-free mouse oocytes with capacitated mouse spermatozoa in the presence of varying concentrations of the antisera against rmtNASP. There was a significant antifertility effect in animals immunized with rmtNASP or the synthesized peptide. The effect on fertility in the mice immunized with the synthesized peptide was reversible. Our data indicate that active immunization with rmtNASP antigen may induce a strong antibody response that causes an inhibition of fertility.

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

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

Morphology of human Fallopian tubes after infection with Mycoplasma genitalium and Mycoplasma hominis--in vitro organ culture study

BACKGROUND

Female infertility can be caused by scarring and occlusion of the Fallopian tubes. Sexually transmitted bacteria can damage the delicate epithelial layer of human Fallopian tubes (HFT). Genital mycoplasmas are associated with human reproductive failure. Yet, there is not enough evidence that mycoplasmas can cause tubal factor infertility. We analysed the effects of infections with Mycoplasma hominis and Mycoplasma genitalium on the HFT epithelium and compared them with the effects of infections with genital pathogens: Chlamydia trachomatis and Neisseria gonorrhoeae.

METHODS

We used an in vitro model in which pieces of normal HFT were infected with different bacteria, and the outcome of the infections was analysed by scanning electron microscopy (SEM) and confocal microscopy.

RESULTS

The presence of M. hominis did not cause any morphological changes of the epithelium of HFT. Noticeable changes in the morphology of the ciliated cells were observed in M. genitalium-infected tissue. Five days post-infection, the cilia were abnormally swollen and some of the ciliated cells fell off the epithelium. These effects could be inhibited by pre-incubation of M. genitalium with antibody directed against the C-terminal part of the adhesion protein MgPa before infection of HFT organ culture.

CONCLUSION

We have shown that the presence of M. genitalium, but not M. hominis, in the HFT organ culture affected the epithelium and resulted in cilia damage. The effect of infection with M. genitalium on the HFT was, however, very moderate when compared with the extensive damage of the epithelium caused by N. gonorrhoeae or C. trachomatis.