Microbial Pathogenesis of Oral Organism

TERRY CONNELL, PhD  personal profile

Iron acquisition in the Bordetellae

A second focus of my laboratory is to investigate the mechanisms by which Bordetella pertussis, B. bronchiseptica, and B. avium, three gram-negative bacteria that infect the upper respiratory tract of children and domesticated animals, acquire essential nutrients required to colonize the respiratory tract and to sustain progressive infections. Iron (Fe) is one of the most important nutrients required by most, if not all infectious bacteria which must be obtained from the tissues and fluids of the infected host. Using proteomic, recombinant, immunological, and biochemical methods, we are unraveling the genetic and molecular components of these bacteria that mediate acquisition of Fe from host-derived heme, myoglobin, and hemoglobin. We have identified a cluster of genes (bhuRSTUV) which encodes five proteins required for uptake of heme and a second gene cluster (rhuIR) which encodes for two heme-dependent regulatory proteins which control heme-dependent expression of the uptake systems. Our current research is focused on analysis of these seven genes and expressed proteins. we are also initiating a proteomics-based analysis of the B. pertussis and B. avium outer membranes using a state-of-the-art Two-dimensional fluorescent gel electrophoresis method (2D-DIGE).

Another area of Dr. Connell's research is available at Immunology and Innate Defenses