Seminal culture: sperm culture

Infertility affects about 15 % of couples seeking pregnancy. Approximately 50 % of these cases are attributable to the male couple. One of the potential causes traditionally described in the literature has been the presence of bacteria in the semen.

Is the presence of bacteria in the semen always pathological?

Not necessarily. The fact of presence of bacteria in our body is widely known. About 10 years ago, the so-called Human Microbiome Project (HMP) was initiated. This project has been progressing faster and faster as molecular techniques have also been evolving. Today, it is estimated that there are more than 10,000 different bacterial species in a healthy organism.

So, are there bacteria specific to the urogenital tract?

Yes, the male urogenital tract is colonized by a number of microorganisms.  According to a study published earlier this year, those patients with seminal alterations presented different profile of microorganisms than those patients with normal seminal quality (normozoospermic). Similarly, the authors of the study were able to identify bacteria that were attributed a protective role from the point of view of seminal quality, such as Lactobacillus, and others with a negative effect, such as Prevotella.

These micro-organisms in semen can come from different locations:

• Urethra
• Prostate
• Epididymis
• Seminal vesicle

What is a semen culture or sperm culture?

It is a test in which the semen is placed in contact with selective and non-selective media that favor the growth of bacteria. If the bacterial growth is observed, we will say that the semen culture has been positive and the microorganism will be identified. The sensitivity of the bacteria to different antibiotics is also studied (antibiogram).

Can we be sure that a seminal infection can affect semen quality?

This is a controversial issue. While some authors do not find this relationship in their work, other authors do relate the presence of seminal infection with alterations in concentration, progressive motility and DNA fragmentation of spermatozoa, among others.

When is a semen culture indicated?

In the following circumstances:

• Presentation of urinary and/or genital tract symptoms.
• Painful ejaculation.
• Presence of blood in the semen (haematospermia).
• Presence of leucocytes in the semen (leucospermia) or greatly increased viscosity.
• Very low semen quality, provided that the doctor finds it appropriate.

In general, it is not advisable to perform a semen culture as a routine procedure prior to assisted reproduction treatment or semen freezing.

How should I collect the semen sample for a sperm culture?

The following factors should be taken into account:

• Maintain sexual abstinence for 3 to 5 days.
• Perform strict genital hygiene before collecting the sample to avoid contamination.
• Collect semen in a sterile container.

What is the treatment for seminal infections?

After a positive result is obtained, an antibiogram will be performed to determine which antibiotic the microorganism causing the infection is most sensitive to.

BIBLIOGRAPHY

1. Jue J.; Ramasamy R. Significance of positive semen culture in relation to male infertility and the assisted reproductive technology process. Translational Andrology and Urology. 2017; 6(5):916-922.
2. Noor S.O.; Albalawi A.; Abduljabbar H. et al. Bacterial analysis for seminal fluid before In-vitro fertilization procedure. Journal of Pharmaceutical Research International. 2020; 32(23):85-92.
3. Yang H., Zhang J, Xue Z. et al. Potential pathogenic bacteria in seminal microbiota of patients with different types of dysspermatism. Nature. 2020; 10:6876.
4. Farahani L.; Tharakan T.; Yap T.; Ramsay J. et al. The semen microbiome and its impact on sperm function and male fertility: A systematic review and meta-analysis. Andrology. 2021; 9:115-144.

Dr Ana Fabregat, a pharmacist at Instituto Bernabeu.

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