Effect of some bacterial products on platelet electrophoretic mobility (PEM)

Bacterial LPS, used in our experiments, are able to decrease PEM at concentration of 100 microgram/ml after incubation with 1 X 10(7) platelets/ml for 30 min at 37 degrees C. Such effect is statistically significant for Bacteroides fragilis LPS, S. enteritidis and S. typhi. E. coli LPS 026:B6 W and E. coli 055:B5 W are not effective at all, S. minnesota (incomplete) LPS 595 and 345 free of 0-polysaccharide and partially lacking core in their molecule did not influence PEM, while S. minnesota LPS (S form) (a complete LPS) strongly decreased PEM. This fact could suggest that 0-polysaccharide is involved in this inhibitory effect on PEM. Klebsiella enterotoxin and B. cereus enterotoxin are able to decrease PEM at concentration of 100 microgram/ml, after incubation with 1 X 10(7) platelets for 30 min at 37 degrees C, while no inhibition of PEM was seen when Shighella enterotoxin and V. parahaemoliticus enterotoxin was used in similar way. The AA. conclude that endotoxin and enterotoxin are able to change the electrokinetic charge (negative) of platelets, thereby, causing a decrease of PEM.