Math Biology Seminar Abstracts

Wednesday, March 27, 2002 3:05 pm LCB 323

Speaker: Christine Litwin, Pathology Department, University of Utah

Title: "Heme Acquisition by Vibrio vulnificus"

Abstract - Vibrio vulnificus is a halophilic, marine pathogen that has been associated with septicemia and serious wound infections. In septicemia, the illness begins within 24 hours after raw oysters have been consumed. Over 75% of patients with septicemia have iron overload due to hemochromatosis, thalassemia, cirrhosis or alcoholic liver disease. The mortality rate for patients with septicemia is greater than 50% despite antibiotic therapy. In many organisms iron-regulated outer membrane proteins function in iron uptake and or virulence. Expression of these iron-regulated proteins is repressed by iron and the ferric uptake repressor (Fur). In V. vulnificus there are at least two major iron-regulated outer membrane proteins (72-kDa and 77-kDa), the vulnibactin receptor (VuuA) and the heme receptor (HupA). We have identified a LysR type transcriptional activator, HupR that is divergently transcribed from the promoter for hupA. Studies suggest that HupR may act as a positive regulator of hupA transcription in the presence of heme.

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