title: Influence of enterococci on human sperm membrane in vitro.
abstract: OBJECTIVE
  To study the influence of enterococci on human sperm membrane in vitro.
  
  
  METHODS
  Ejaculated human sperm were artificially infected with beta-hemolytic or non-beta-hemolytic enterococci at the bacteria: sperm ratio of 50:1 at 37 degrees . Sperm membrane integrity was examined after incubation for 1, 3 and 5 h by hypoosmotic swelling (HOS) test and electron microscopy.
  
  
  RESULTS
  Sperm infected with beta-hemolytic enterococci had lower HOS scores compared with non-beta-hemolytic strains or uninfected control (P < 0.01). The HOS test scores of sperm infected with beta-hemolytic enterococci increased in the presence of phosphatidylcholine, an inhibitor of hemolysin. Non-beta-hemolytic strains showed no significant difference in swelling rate, compared with the control group (P > 0.05). It was shown by electron microscopy that beta-hemolytic enterococci caused significant rupture of human sperm membrane.
  
  
  CONCLUSIONS
  Beta-hemolytic enterococci caused human sperm membrane injury, and might be mediated by the hemolysin of enterococci.
authors.affiliation: Department of Pathogenic Biology Etiology, School of Medicine, Wuhan University, Wuhan 430071, China. qianghua66@sina.com
authors.forename: Hua
authors.initials: H
authors.lastname: Qiang
authors.forename: Ming-Sen
authors.initials: MS
authors.lastname: Jiang
authors.forename: Jian-Yin
authors.initials: JY
authors.lastname: Lin
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: He
mesh_terms: D002462:Cell Membrane / Q000187:drug effects / Q000382:microbiology*; D004542:Ejaculation; D016983:Enterococcus / Q000502:physiology*; D005243:Feces / Q000382:microbiology; D006801:Humans; D008297:Male; D010713:Phosphatidylcholines / Q000494:pharmacology; D012016:Reference Values; D013094:Spermatozoa / Q000187:drug effects / Q000382:microbiology* / Q000648:ultrastructure
chemical_list: D010713:Phosphatidylcholines