Interference of Human Spermatozoal Motility by Live Staphylococcus aureus

The aim of this work was to investigate the effect of live Staphylococcus aureus commonly present in the cervix of females on sperm motility and agglutination in vitro. Highly motile samples of spermatozoa (40 x 10 6 /ml) from normozoospermic males were co-incubated for 4h with 10 7 cells/ml of live S. aureus. After 30 minutes, 1, 2 and 4h of incubation, sperm motility and agglutination was checked by light microscopic examination (X 400). From the onset, it was apparent that the live bacteria reduced the motility of spermatozoa. The promptness with which the decreased motility was observed to occur in the live S. aureus group was striking. After 30 minutes of mixing the ejaculate with the live bacteria, decrease in motility and clumping of the spermatozoa was noted. Interestingly, no agglutination and immobilization was observed in other experiments in which the bacteria were killed by heat, lysozyme or antibiotics and mixed with the ejaculate. Certainly, it seems evident that live S. aureus can significantly depress the motility and agglutinate human spermatozoa in vitro. The mechanism by which this alteration takes place is not obvious, however, detrimental effect on sperm motility by live staphylococci may be an as yet unrecognized component of fertility problems.