1Wahby AF, 2El-Kady
EM, and 3Osman MN.
Departments of 1Molecular
Biology and 2Microbial Biotechnology, National Research Center,
Cairo, Egypt and 3Bacterial Vaccines, The Egyptian Organization for
Biological Products and Vaccines.
Culture supernatants of Bordetella pertussis (B.
pertussis) strains 134 and 509 grown in a fully monitored fermentor were
concentrated by ultrafiltration. Two PT enriched fractions (F3 and F4), were
obtained by direct chromatography of the fresh concentrated supernatant of B.
pertussis strain 134 on Sephacryl S-300. The two fractions contained high
concentrations of the intact PT as judged by cytotoxicity for CHO cells and the
high ELISA titers for PT. The glutaraldehyde inactivated F3 and F4 were more
potent than glutaraldehyde inactivated PT in protection of mice against
virulent B. pertussis as judged by vaccination challenge experiments.
The relatively simple procedures for preparation of these immunogenic fractions
make them good candidates for preparation of acellular vaccines. The
supernatants were unstable at 4ºC, a soluble fraction and an insoluble fraction
were resolved by low speed centrifugation. Whereas, highly aggregated proteins
were obtained on reconstitution of the lyophilized supernatants. Immunoblots,
developed with two rabbit antisera to whole cell pertussis vaccine (WCV) and
the supernatant antigens revealed that the insoluble fraction contained most of
the filamentous hemagglutinin (FHA), whereas the soluble fraction contained
most of the pertussis toxin (PT).