BINDING OF HUMAN HEMOGLOBIN BY HAEMOPHILUS-INFLUENZAE

Binding of biotinylated human hemoglobin to Haemophilus influenzae was detected when organisms were grown in heme-deplete, but not heme-repl ete, conditions. Hemoglobin binding was completely inhibited by a 100- fold excess of unlabelled human hemoglobin or human hemoglobin complex ed with human haptoglobin. Binding was only partially inhibited by rat hemoglobin, bovine hemoglobin, human globin, and bovine globin, and n ot at all by heme, human serum albumin, bovine serum albumin, human tr ansferrin, or myoglobin. Hemoglobin binding was saturable at 16-20 ng of hemoglobin per 10(9) cfu. Binding of human hemoglobin was detected in serotypes a-f and serologically non-typable strains of H. influenza e, as well as Haemophilus haemolyticus but not Haemophilus parainfluen zae, Haemophilus aphrophilus, Haemophilus parahaemolyticus, or Escheri chia coil.