Quantitative Assay of B. pertussis Lipopolysaccharide.

We studied activity of Bordetella pertussis LPS in the LAL test. The mean activity of various series of LPS preparations obtained from B. pertussis cells ranged from 1,950,000 to 2,940,000 endotoxin units/μg (EU/μg). Activity of the LPS preparation obtained from the culture medium supernatant was significantly higher (4,640,000 EU/μg). Activity of the control standard E. coli 055:B5 LPS was 19,500±500 EU/μg. These data indicate that activity of the obtained preparations of B. pertussis LPS in the LAL test is 100-200 times higher than activity of E. coli LPS used as a reference control. It was concluded that the results of the LAL test when assessing the permissible content of B. pertussis endotoxins require correction, probably by introducing a correction factor.