High incidence of oligozoospermia and teratozoospermia in human semen infected with the aerobic bacterium Streptococcus faecalis.

Bacterial culture of semen samples from 100 male partners in infertile couples revealed the presence of aerobic bacteria in 49 cases. Streptococcus faecalis (Enterococcus) was isolated from 53%, micrococci species from 20% and alpha-haemolytic streptococci from 16% of the infected samples. The incidence of oligozoospermia and teratozoospermia was significantly (P < 0.05) higher in men whose semen samples contained S. faecalis than those whose semen samples contained micrococci or alpha-haemolytic streptococci or those that did not contain bacteria. The mean sperm concentration, as well as the mean percentage of morphologically normal spermatozoa, was significantly (P < 0.03) lower in semen infected with S. faecalis compared with that containing micrococci or alpha-haemolytic streptococci and the uninfected samples. There is a high incidence of semen infection with S. faecalis, and it is associated with compromised semen quality in terms of sperm concentration and morphology. The presence of micrococci or alpha-haemolytic streptococci does not appear to have any detrimental effect on sperm quality.