DOI:
ABSTRACT
Mutant cultures that lacked the ability to produce filamentous hemagglutinin were obtained by UV irradiation of Bordetella pertussis strain 18-323. Various biological activities of these mutants were compared with those of the parent culture. It was found that the leukocytosis-promoting, histamine-sensitizing, and mouse-protecting activities of the mutants were similar to those of the parent strain but that the virulence to mice was lower. The results seemed to rule out fimbrial hemagglutinin as a protective antigen when the ability to protect mice was measured by the intracerebral challenge test.
