Semen

N. B. Prostatic fluid submitted for the diagnosis of prostatitis is a much more common specimen and is processed differently. See Prostatic fluid for the diagnosis of prostatitis.

Though controversial, bacterial infections of the seminal tract have been postulated to play a role in male infertility and semen is occasionally submitted for culture.

Potential pathogens include N. gonorrhoeae, S. aureus, Enterococci, Beta-hemolytic streptococci and coliforms. Possible pathogens in seminal fluid at concentrations >106 CFU/L is defined as “significant bacteriospermia” which may be associated with infertility. However, bacteria in these concentrations may also represent contamination given the circumstances of sample collection and colonization of the peri-urethral area.

Setup

Direct Examination

Not Indicated

Culture

Use a 10 μl disposable culture loop to inoculate plates.

Media Incubation
Blood Agar (BA) CO2, 35°C x 48 hours
MacConkey Agar (MAC) O2, 35°C x 48 hours
Chocolate Agar (CHOC) CO2, 35°C x 48 hours
Vancomycin-Colistin-Nystatin Agar (VCN) CO2, 35°C x 72 hours

Possible Seminal Tract Pathogens

  • Neisseria gonorrhoeae (in any amount)
  • Enterobacteriaceae
  • Pseudomonas aeruginosa
  • Other gram negative bacilli
  • Enterococci
  • Staphylococcus aureus
  • Beta-haemolytic streptococci

Non-Seminal Tract Pathogens

  • diphtheroids
  • coagulase-negative staphylococci
  • Bacillus spp.
  • viridans streptococci
  • Lactobacillus spp
  • Yeasts

Interpretation Perform total colony count on all morphotypes of Possible Seminal Tract Pathogens isolated on BA. (Count includes only Possible Seminal Tract Pathogens considered together)

Non-Seminal Tract Pathogens

In any amount – No Work-up

Possible Seminal Tract Pathogens

Less than 10 colonies – No Work-up

10 colonies or more – ID and susceptibility of all isolates

Reporting

Negative Report

“No Growth” “No Neisseria gonorrhoeae isolated”. If VCN plate is overgrown by swarming Proteus or yeast, report ONLY as “Unable to rule out Neisseria gonorrhoeae due to bacterial/yeast overgrowth.”

Non-seminal tract pathogens and/or < 106 CFU/L (<10 colonies) possible seminal tract pathogens – “No significant growth”

Positive Report

Greater than 10 colonies possible seminal tract pathogens

Report: Greater than 106 CFU/L {organism name} and add comment “This fulfills the criteria for ‘significant bacteriospermia’ however the relationship to infertility is unclear.”

“Neisseria gonorrhoeae” isolated (do not quantitate), beta lactamase non-producing or producing strain. Insert comment “Report has been copied to Medical Officer of Health”.

Telephone all positive GC cultures to floor/ordering Physician.

For all positive GC cultures, a Communicable Disease Report is sent to the Medical Officer of Health and is recorded in the significant isolates log book.

References Keck C, et al. 1998. Seminal tract infections: impact on male fertility and treatment options. Human Reproduction Update 4(6):891-903.

Jarvi K, et al. 1996. Polymerase chain reaction-based detection of bacteria in semen. Fertility and Sterility 66(3):463-467.

Cottell E. Fertility and Sterility 2000 74(3):465-470.

World Health Organization. 1992. Laboratory Manual for the Examination of Human Semen and Sperm – Cervical Mucus Interaction, 3rd ed. Cambridge University Press, Cambridge.