Mechanism of Sperm Immobilization byEscherichia coli

[摘要] Aim. To explore the influence ofEscherichia colion the motility of human spermatozoa and its possible mechanism.Methods. Highly motile preparations of spermatozoa from normozoospermic patients were coincubated withEscherichia colifor 4 hours. At 1, 2 and 4 hours of incubation, sperm motility was determined. The factor responsible for sperm immobilization without agglutination was isolated and purified from filtrates.Results. This report confirms the immobilization of spermatozoa byE. coliand demonstrates sperm immobilization factor (SIF) excreted byE. coli. Further this factor was purified by ammonium sulfate precipitation, gel permeation chromatography, and ion-exchange chromatography. Purified SIF (56 kDa) caused instant immobilization without agglutination of human spermatozoa at 800 μg/mL and death at 2.1 mg/mL. Spermatozoa incubated with SIF revealed multiple and profound alterations involving all superficial structures of spermatozoa as observed by scanning electron microscopy.Conclusion. In conclusion, these results have shown immobilization of spermatozoa byE. coliand demonstrate a factor (SIF) produced and secreted byE. coliwhich causes variable structural damage as probable morphological correlates of immobilization.

[学科分类] 泌尿医学