Bacteriospermia and male infertility: a method for increasing the sensitivity of semen culture

To test a method for increasing the sensitivity of semen culture. Design-Prospective and transverse. Setting-Andrology clinic at a tertiary care health institution in Mexico City.

65 infertile patients with abnormal semen, bacteriospermia detected on Gram stain and at least two previous negative semen cultures (<3 months) were included to test routine semen culture and a method including centrifugation of semen at 10,00 rpm for 20 minutes. Localization cultures were also carried out in all patients.

Bacterial isolation in semen samples.

Routine semen culture was positive in 22% of patients, while centrifuged aliquots of the same semen sample were positive in 52% of patients (chi2 = 6.60, P < .01). Enterococcus was isolated in 43% of patients, E. coli in 24%, coagulase-negative Staphylococcus in 19%, and U. urealyticum in 14%. Ninety percent of isolates corresponded to specimens from the urethra and the prostato-vesicular region.

Sensitivity of semen culture increased with centrifugation of semen samples. Localization pattern and type of isolates suggest that these patients had chronic prostatitis and that episodic elimination of bacteria might also explain false negative semen cultures in patients with chronic asymptomatic infection of the accessory sex glands.