The present study was focusing on the effect of seminal fluid infection on sperm functions and fertilizing capacity of mouse spermatozoa. Two kinds of bacteria were isolated from seminal fluid of 14 infertile patients (23-51 years) during their attendance at the Institute of Embryo Research and Infertility Treatment involves Staphylococcus aureus (Staph. aureus) and Escherichia coli (E. coli), which were identified by biochemical tests and API systems. On the present project, the virulence effects of these two kinds of bacteria and their culture filtrates at viable number 3, 6, 12, 24, 36 and 48 X103 cell/ml were analyzed on the mouse sperm function tests involving sperm concentration, percentage of sperm motility, percentage of progressive motile spermatozoa, percentage of abnormal sperm morphology, percentage of sperm agglutination and percentage of in vitro fertilization at zero time and after 30 and 60 minutes of bacterial or culture filtrates incubation.The results showed that E coli infection had highly harmful effects on most of the spermatozoa parameters studied of mouse spermatozoa than Staph aureus. E. coli was significantly (P<0.05) reduced the motility of mouse spermatozoa after 30 minutes of incubation with the count 6X103 cell/ml, meanwhile Staph aureus begin its negative effect at the count 24X103 cell/ml after 30 minutes of incubation. The percentages of abnormal sperm morphology and sperm agglutination were significantly (P<0.05) affected by E. coli at bacterial count 36X103 cell/ml after 30 minutes of incubation and mouse spermatozoa were destroyed in average 40% after 60 minutes of incubation, meanwhile Staph. aureus had no effects on these two parameters. The present investigation showed that the percentage of the IVF outcomes was significantly (P<0.05) reduced in the presence of E. coli at all counts and after any time of incubation, in contrast, the spermatozoa incubated with Staph. aureus showed a reduced ability for IVF till the bacterialconcentration 24X103 cell/ml after 30 minutes of incubation. Culture filtrates of E. coli and Staph. aureus had lower effects on mouse sperm function tests than its living cells. Culture filtrates of E. coli developed its negative effectiveness significantly (P<0.05) on the percentage of sperm motility at the count 24X103 cell/ml after 30 minutes of incubation. Meanwhile, the culture filtrates of Staph. aureus at a count of 48X103 cell/ml reduced the percentage of sperm motility significantly (P<0.05). The percentages of abnormal sperm morphology and sperm agglutination were significantly (P<0.05) affected by E. coli culture filtrates at count 36 and 48 X 103 cell/ml after 30 minutes of incubation while Staph. aureus had no effect on both parameters.Spermatozoa which were incubated for 30 min. with culture filtrates of E. coli significantly (P<0.05) reduced the percentage of IVF at the counts 3 and 6 X 103 cell/ml to 12.50% and 27.77%; respectively, whereas, the fertilizing capability of spermatozoa incubated for 60 min with Staph. aureus culture filtrates were 37.5% and 17.64% at the counts 36 and 48 X103 cell/ml after 60 minutes of co-incubation.In conclusion, bacterial infections of seminal fluid have serious and harmful effects on sperm functions and fertilizing capability of mouse spermatozoa.
