Fimbrial Typing of Bordetella pertussis Isolates: Agglutination with Polyclonal and Monoclonal Antisera

As established by Eldering et al. (3), fimbrial antigens of Bordetella pertussis cells were used to raise agglutinating antibodies and have thus been called agglutinogens, which are constitutive parts of two fimbrial proteins, Fim2 and Fim3, and of an outer membrane protein called pertactin (Prn), respectively (1, 2). On the basis of this, monoclonal antibodies to Fim2 and Fim3 were obtained (4), and B. pertussis isolates can be typed as being either Fim2, Fim3, or Fim2,3 (5). Polyclonal antisera to agglutinogens 2 and 3 were available commercially, and a microagglutination procedure for serotyping isolates, which has been used for many years, has been described previously (7). Fimbrial typing of the same isolates done either with polyclonal or with monoclonal antisera, however, has not been compared. Thus, we compared the results obtained with two different sets of polyclonal antisera and one set of monoclonal antisera.