The initial step in establishing a Bordetella pertussis infection is attachment of the bacteria to the epithelial lining of the host respiratory tract. Two B. pertussis virulence factors are key in this process, filamentous hemagglutinin (FHA) and fimbriae (Fim). Fimbriae are extracellular proteins which like FHA participate in the attachment of bacteria to substrates. Based on their reaction to sera, there are two fimbriae serotypes present in B. pertussis, fimbriae 2 (Fim 2) and fimbriae 3 (Fim 3).
Although fimbriae are long structures which serve to tether the bacterial to surfaces, they are composed of subunits which dissociate in SDS producing components with apparent molecular weights of 22,500 and 22,000 Da for Fim 2 and Fim 3, respectively. Interestingly, antibodies raised to native Fim do not react well with SDS-denatured subunits. Fim 2/3 produced and sold by List is isolated from cultures of a PRN- mutant derived from the Bordetella pertussis Welcome strain 28 and consists of a mixture of fimbriae 2 and fimbriae 3.
Other Bordetella pertussis virulence factors derived from native organisms and offered by List Labs include Pertussis Toxin, Pertussis Toxin Subunits, Pertussis Toxin Mutant, Filamentous Hemagglutinin (FHA), Pertactin (69 kDa protein), Adenylate Cyclase Toxin (ACT), Adenylate Cyclase Antigen and B. pertussis Lipopolysaccharide (LPS). More information about each of these products may be obtained through the links on the Bordetella Virulence Factors.