Study of several genetic markers of two recombinants derived from autochthonous influenza virus type A strains.

Two recombinants derived from autochthonous influenza virus type A strains were studied as regards neuraminidase activity, the rate of elution from chicken RBC and the sensitivity to nonspecific horse serum inhibitors. Neuraminidase activity was lower in the A(H1N1) recombinant and in its collection and wild-type parents belonging to the same subtype than in the A(H3N2) recombinant and parental strains; the elution rate was much higher in the former than in the latter. In contrast to the parental strains, both recombinants were resistant to horse serum inhibitors.