Correlation between the ability of Haemophilus paragallinarum to acquire ovotransferrin-bound iron and the expression of ovotransferrin-specific receptors

• Published in: Avian diseases Vol. 36; no. 3; p. 655
• Main Authors: Ogunnariwo, J.A. (University of Calgary, Calgary, Alberta, Canada), Schryvers, A.B
• Format: Journal Article
• Language: English
• Published: United States 01.07.1992
• Subjects: ABSORCION; ABSORPTION; Binding, Competitive; Conalbumin - metabolism; CRECIMIENTO; CROISSANCE; FER; GLOBULINAS; GLOBULINE; HAEMOPHILUS; Haemophilus - metabolism; HAEMOPHILUS PARAGALLINARUM; HIERRO; Iron - metabolism; Protein Binding; Receptors, Transferrin - analysis; Receptors, Transferrin - metabolism; Siderophores - biosynthesis; Transferrin - metabolism
• ISSN: 0005-2086; 1938-4351
• DOI: 10.2307/1591761

To investigate the mechanisms of iron acquisition in avian haemophili, strains of Haemophilus paragallinarum and H. avium were tested for siderophore production and utilization of transferrin iron for growth. No evidence of siderophore production was detected in either of these species using a functional screening assay H. paragallinarum, but not strains of H. avium, was able to acquire iron from 30% saturated chicken and turkey transferrins but not from human, porcine, or bovine transferrins. In response to iron limitation, H. paragallinarum expressed four iron-regulated outer membrane proteins of 53, 62, 66, and 94 kilodaltons (kDa). Only the 53- and 94- kDa proteins were detected in the H. avium strains. Using affinity methods, the 94 and 53-kDa proteins were isolated specifically, by chicken or turkey transferrin, indicating that they may be equivalent to transferrin binding proteins (TBP1 and TBP2, respectively) isolated from other bacterial species. The isolation of the 62- and 66-kDa proteins in association with TBP1 and TBP2 under less stringent washing conditions only in H. paragallinarum implicates these proteins in the iron acquisition process