Specific lipopolysaccharides of Bordetella

N.C.T.C. 8250, were obtained from the National Collection of Type Cultures, Colindale, London. Of the four B. bronchisepticus strains, 452 and 454 were avirulent (A. P. MacLennan, unpublished work), but a third avirulent strain, 8759Av, was derived from N.C.T.C. 8759 by rc- peated transplanting of broth cultures. A phase IV B. pertussis strain, G 154 E, and an acetone-dried preparation of phase I organisms were kindly provided by Dr Jean Dolby, The Lister