Adherence of Escherichia coli to sperm: a mannose mediated phenomenon leading to agglutination of sperm and E. coli.
OBJECTIVE
To investigate the mechanism of adherence between Escherichia coli and sperm.


METHODS
Experimental study performed with donor sperm and male genital tract-derived E. coli.


METHODS
Andrology unit of a university hospital.


METHODS
None.


METHODS
Monitoring of sperm-E. coli agglutination; addition of sugars to block adherence; electron microscopy.


METHODS
Sperm-E. coli agglutination.


RESULTS
Escherichia coli readily adhered to and agglutinated sperm. The phenomenon was observed at E. coli to sperm ratios as low as 1:20; maximum sperm agglutination involving approximately 90% of spermatozoa was seen with ratios of 1:5 or higher. By transmission electron microscopy, E. coli adherence was observed both on sperm heads and tails. Heteroagglutination could be blocked by D-mannose and alpha-methyl-mannopyranoside but not by other sugars. Preincubation of sperm or E. coli with mannose resulted in block of agglutination, indicating mannose-binding structures both on sperm and E. coli.


CONCLUSIONS
Adherence of E. coli to sperm is mediated by mannose and mannose-binding structures present on both cell types. Agglutination of sperm by E. coli may be relevant in male and female infertility.
Dermatologische Klinik und Poliklinik, Ludwig-Maximilians-Universität München, Germany.
H
H
Wolff
A
A
Panhans
W
W
Stolz
M
M
Meurer
D001422:Bacterial Adhesion / Q000187:drug effects / Q000502:physiology*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008358:Mannose / Q000494:pharmacology; D008766:Methylmannosides / Q000494:pharmacology; D008854:Microscopy, Electron; D013073:Sperm Agglutination / Q000187:drug effects / Q000502:physiology*; D013094:Spermatozoa / Q000187:drug effects / Q000382:microbiology / Q000502:physiology*
D008766:Methylmannosides; C008466:methylmannoside; D008358:Mannose