Studies on the significance of positive bacterial semen cultures in male fertility in Nigeria.

OBJECTIVE: Early warning signals (EWS) of altered reproductive potential may be very important in the prevention and management of male infertility. The presence of bacteria in semen (bacterisemia) may be an EWS. This was evaluated by determining the incidence of bacteria in semen of males with fertility problems in Benin City by culturing their semen.
METHODS: Diluted semen samples were cultured on blood agar, chocolate agar, MacConkey agar, nutrient agar, and sabouraud dextrose agar slants for the isolation of micro-organisms. Colonies of a single type of micro-organism (>10(3) cfu/mL) were picked for identification and sensitivity tests using antibacterial agents. Each semen sample was further processed for spermatozoal morphology and motility, presence of peroxidase-positive cells, and other accompanying cells. Correlative studies on the relationship between bacterisemia and semen/spermatozoa variables such as total number and motility were also done.
RESULTS: Pathogenic micro-organisms were present in 78/163 (47.1%) semen samples. The microbial isolates were Staphylococcus aureus 35 (43.7%), Klebsiella species 22 (28.2%), Escherichia coli 9 (11.5%), and Candida albicans 6 (7.7%). The bacterial isolates were most sensitive to ceftazidime and pefloxacin, and least to amoxycillin and tetracycline. There was a positive correlation (r = .9774) between azoospermia in males and presence of Candida albicans in semen, as well as between the presence of micro-organisms and poor semen quality (r = .8563), and the presence of micro-organisms and reduced motility (r = .8246).
CONCLUSION: Presence of pathogenic micro-organisms in semen, which may be related to a breach in the integrity of the blood-testes barrier, may provide early warning signals of impairment of male fertility.