Influence of bacterial products on the motility of stallion spermatozoa.

Sterile filtrates were prepared from equine isolates of Klebsiella pneumoniae (genitalium), Proteus mirabilis, Pseudomonas aeruginosa, Escherichia coli, Streptococcus zooepidemicus, Streptococcus equisimilis, Actinobacillus equuli, and Corynebacterium equi and mixed individually with extended stallion semen. When diluted in the extended semen the filtrates represented bacterial populations of 0.5 x 10(6), 1 x 10(6), 2 x 10(6) and 4 x 10(6) cells/ml. pH values were recorded for each filtrate. Specimens were monitored for percentage motile spermatozoa at 30-min intervals until they reached 10% or less for 2 consecutive observations. All specimens were maintained at 25 degrees C in a water bath. Ten specimens were examined from each of 5 clinically normal stallions. The major reduction in percentage motile spermatozoa as compared to the control sample occurred before the first observation. From this point the rate of deterioration in motility in the filtrates approximated that of the control. The differences detected between the filtrates and control in percentage motile sperm cells were all statistically significant at P less than 0.01.