The role of aerobic and anaerobic semen cultures in asymptomatic couples undergoing in vitro fertilization: effects on fertilization and pregnancy rates

Round Cells in Diagnostic Semen Analysis: A Guide for Laboratories and Clinicians

Round cells in seminal fluid are defined as either leucocytes or immature germ cells. Laboratories undertaking semen analysis often report these combined as a concentration, with no further review, comment or direction for clinician action or review. Although numerous publications discuss the possible clinical relevance of these cells (particularly leucocytes) in infertility, the methods employed to differentiate them are often beyond the scope of most diagnostic laboratories. This paper aims to support healthcare scientists in understanding the clinical significance of round cells and aid their identification, differentiation and interpretation. This will support the quality of care the patient receives and direct clinicians to further considerations that may be appropriate for their patient and should consequently reduce indiscriminate and unnecessary use of antibiotics.

Can apoptosis and necrosis coexist in ejaculated human spermatozoa during in vitro semen bacterial infection?

PURPOSE

To evaluate whether ejaculated human spermatozoa undergo complete apoptosis or necrosis during experimental semen bacterial infection in vitro.

METHODS

Apoptotic markers, including mitochondrial transmembrane potential (ΔΨm), phosphatidylserine (PS) externalization, and DNA fragmentation, have been detected simultaneously in ejaculated human sperm after their incubation with a known pathogenic (Escherichia coli), as well as with conditionally pathogenic bacterial strains (Staphylococcus haemolyticus, Bacteroides ureolyticus) and/or leukocytes. The ΔΨm and translocation of PS was evaluated using the JC-1 and Annexin V binding tests, respectively. A modified TUNEL assay with additional staining for sperm viability was used to detect the DNA fragmentation level.

RESULTS

The exposure of ejaculated spermatozoa to bacterial strains was associated with a simultaneous decrease in the percentage of sperm with normal ΔΨm and an increase in the proportion of Annexin V-positive sperm. Additionally, in the presence of S. haemolyticus, B. ureolyticus and/or leukocytes, a significant increase in the percentage of live TUNEL-positive (apoptotic) as well as dead TUNEL-positive (necrotic) sperm cells was also observed.

CONCLUSIONS

The cellular death observed in spermatozoa in the presence of inflammatory mediators may be due to both apoptosis and necrosis. Here, we demonstrate for the first time that direct contact of conditionally pathogenic bacteria with ejaculated human sperm may play an even greater role in the promotion of apoptosis than in case of some pathogenic bacterial strains. These findings suggest that significant bacteriospermia and leukocytospermia may be direct causes of subfertility or additional negative factors worsening the prognosis of fertility in natural and assisted procreation.

SIGNIFICANCE OF SEMEN CULTURES FOR MEN WITH QUESTIONABLE SEMEN QUALITY

Semen cultures often yield inconclusive results probably due to bacterial contaminants. We were able to isolate enteric pathogens with greater specificity by comparing two cultures from the same individual: one obtained from the midstream urine and the other from ejaculate obtained following midstream urine collection and eliminating the bacteria present in the midstream urine. Bacterial growth was found in semen cultures from 102 (79%) of the 129 men with questionable semen quality; 31 (30%) had aerobic bacteria, 28 (27%) had anaerobic bacteria, and 43 (42%) had both. A high incidence of positive cultures in our study was probably due to stringent patient selection and our comparative culturing procedure. The presence of pathogens may indicate the need for treatment especially prior to IVF and IUI.

Consequences of semen inflammation and lipid peroxidation on fertilization capacity of spermatozoa in in vitro conditions

A body of data exists on reactive oxygen species (ROS) release, however, no direct correlation was found between the oxidative stress and infertility. The aim of the study was to measure semen oxidative stress and its correlation with classical in vitro fertilization (IVF) rate. A prospective study in academic non-profit institution where 79 infertile couples were subjected to IVF programme was conducted. Two infertile groups were discriminated according to the pronuclei presence in IVF. The main outcome measure (pronuclei presence) was then correlated with lipid peroxidation product in semen (ROS effect). Although the average IL-8 levels and malondialdehyde (MDA) content in semen did not differ between the studied subgroups (successful vs. non-successful fertilization), a statistically significant negative correlation was found between MDA level and fertilization rate in performed regression analysis. Thus we may suggest that MDA levels in seminal plasma may have prognostic value for IVF success.

Infection du tractus génital masculin : le point de vue du bactériologiste

Male genital tract infection and inflammation have been associated to 8 to 35% of male infertility cases in various studies. Their investigation is part of a multi-disciplinary process including new techniques as DNA integrity study. Bacterial seminal infection can cause transient or chronic persistent inflammation, and the microbiological investigations, as well as leukospermia, secretory chlamydial IgA and inflammatory cytokines help to approach the responsibility of inflammation in infertility or pathological condition, leading to antibiotic and anti-inflammatory treatment. In Assisted Reproductive Techniques (ART), bacteriospermia must be eradicated for a safe semen preparation to inseminate or to fertilize oocytes. Leukocytes cannot be completely eliminated by sperm preparation and the presence of antibiotics and antioxydants in the culture media is questionned.

Ureaplasma urealyticum-harmless commensal or underestimated enemy of human reproduction? A review

This article reviews the role, diagnosis and treatment of Ureaplasma infections in human reproduction.

Bacterial contamination and sperm recovery after semen preparation by density gradient centrifugation using silane-coated silica particles at different g forces

The effects of density gradient centrifugation through silane-coated silica particles (PureSperm) using 100, 200, 300 and 500 g on bacterial contamination of sperm samples and recovery of motile spermatozoa from sperm samples were investigated with conventional culturing techniques and microscopic visual assessment. The recovery of motile spermatozoa was variable and was not improved using 500 g compared to the recommended 300 g. The bacterial contamination was highly decreased by gradient centrifugation through PureSperm and was almost abolished when strict aseptic techniques were used, with changes to sterile Pasteur pipettes and tubes prior to washing procedures.

Accurate detection of male subclinical genital tract infection via cervical culture and DNA hybridization assay of the female partner

The accuracy of the PACE2 DNA hybridization assay of the cervix and cervical culture in female partners for the diagnosis of male subclinical genital tract infection were assessed in a male infertility population. A total of 184 men were screened for the presence of Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis. Seventy-one men were identified with a positive test for one or more of the above mentioned micro-organisms. The overall prevalence of bacterial infection was 39%. Female partners of all men were tested with the PACE2 DNA hybridization assay to detect a C. trachomatis infection. Sensitivity was 100% and specificity was 100%. In 67 female partners (94%) of men who tested positive for U. urealyticum and/or M. hominis, a cervical swab culture was performed. The sensitivity of the cervical swab culture was 100%. In view of the high prevalence of U. urealyticum and M. hominis in the male genital tract and the role these sexually transmitted pathogens may play in infertility, one might question whether all couples should be screened for the presence of these pathogens. Transurethral swab culture after digital prostatic massage is disincentive to men. The cervical culture in their female partner, performed as part of the routine fertility work-up, is a suitable alternative to detect the presence of these micro-organisms in the male genital tract.

Ureaplasma urealyticum in semen: is there any effect on in vitro fertilization outcome?

OBJECTIVE

To determine the effect of the presence of Ureaplasma urealyticum in semen on IVF outcome (fertilization, pregnancy, and abortion rates).

DESIGN

Prospective study.

SETTING

Private IVF unit in Athens, Greece.

PATIENT(S)

One hundred ninety-one asymptomatic men with normal semen parameters whose wives underwent an IVF cycle.

INTERVENTION(S)

Culture of semen for U. urealYticum on the day of oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Fertilization, pregnancy, and abortion rates after IVF.

RESULT(S)

Ninety-six (86%) of the 112 women whose husbands' semen was negative for U. urealyticum and 65 (82%) of the 79 women whose husbands' semen was positive for U. urealyticum underwent ET. The pregnancy rate (PR) was 20% (19/96) in the negative group and 17% (11/65) in the positive group. An increased incidence of abortions (6/11) was observed in the positive group (abortion rate, 54%), compared with 21% (4/19) in the group of women whose husbands' semen was negative for U. urealyticum.

CONCLUSION(S)

Fertilization rates and PRs may not be affected by the presence of U. urealyticum in semen on the day of oocyte retrieval. It can be presumed that the semen preparation for IVF cleanses the semen of U. urealyticum. On the other hand, the higher abortion rate in the U. urealyticum-positive group might be related to maternal factors, such as an existing U. urealyticum infection or one contracted after conception.

Influence of bacteria and leukocytes on the outcome of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI)

The influence of bacteria and/or leukocytes on the outcome of IVF or ICSI is influenced by three factors which have little in common with in vivo conditions: 1) The process of ejaculate preparation (swim-up, Percoll) with antibiotic buffered media; 2) The small amount of inseminated spermatozoa (100,000 per culture); 3) The short cultivation time. From the very beginning, these factors limit whatever the influence of bacteria and leukocytes on fertilization and embryonic development in vivo may be. Despite the contradictory results published so far, the influence of bacteria and/or leukocytes on the functional integrity of spermatozoa during the process of IVF or ICSI can be ignored. Furthermore, during IVF or ICSI the spermatozoon does not act as a vector for the transportation of bacteria into the ooplasm.

Processing of semen in an antibiotic-rich culture medium to minimize microbial presence during in vitro fertilization

OBJECTIVE

To identify and determine the prevalence of microorganisms in preprocessed and postprocessed semen in an IVF-ET program.

DESIGN

Prospective study.

SETTING

University Teaching Hospital.

PATIENT(S)

Seventy-four men undergoing preprogram evaluation, each producing two semen samples.

INTERVENTION(S)

Semen processing with a wash and swim-up technique in a penicillin- and streptomycin-rich medium.

MAIN OUTCOME MEASURE(S)

The identity and prevalence of seminal microorganisms before and after processing.

RESULT(S)

Sixty-three percent of individual unprocessed semen samples grew microorganisms, the majority of which were nonpathogenic. Thirty-three men (44.6%) had microbes identified in repeat samples, four had identical organisms each time. Twenty (27%) had positive cultures in one sample, negative in the other. Twenty-one (28.4%) had consistently sterile semen. After seminal processing, the recovery rate for microbes was 5%. Microbial presence after processing did not correlate with either the sperm swim-up concentration or the initial microbial concentration.

CONCLUSION(S)

Bacteriospermia is common. The microorganisms found rarely are replicated and most likely represent contamination. Wash and swim-up semen preparation in an antibiotic rich culture medium effectively eliminates 95% of organisms.

Peroxidase-positive round cells and microorganisms in human semen together with antibiotic treatment adversely influence the outcome of in-vitro fertilization and embryo transfer

Human semen contains not only spermatozoa but also other cells routinely differentiated as being peroxidase-positive (e.g. leucocytes) and peroxidase-negative (e.g. immature germ cells and lymphocytes) cells. Considerable uncertainty exists about their role in male fertility. To assess the clinical value of both parameters, and of microorganisms in semen, 391 treatments with in-vitro fertilization and embryo transfer were analysed retrospectively, and the concentrations of both peroxidase-positive and -negative cells, together with the presence of microorganisms in semen, were compared with both the fertilization and pregnancy rates. The data indicate that the results of treatment were affected only by excessively elevated concentrations of peroxidase-positive cells (> 6 x 10(6)/ml) and only marginally by the presence of microorganisms in the semen. The pregnancy rate after in-vitro fertilization and embryo transfer was not improved by antibiotic treatments preceding gamete recovery by several weeks. The increased presence of peroxidase-negative cells (e.g. germ cells) in semen was not associated with a significant change in the pregnancy rate. However, the concentration of peroxidase-negative cells in semen correlated significantly with sperm numbers (p < 0.01), sperm concentration (p < 0.01), and normal morphology rates (p < 0.01). It is concluded that short-term antibiotic treatment of asymptomatic patients before assisted reproduction should be handled with caution. The widespread view that peroxidase-negative cells in semen are harmful is rejected.