Rachel Conrad, PhD candidate in the Department of Biological Sciences at UW-Milwaukee, will present a talk about her research, entitled ‘Roles of Secreted Proteins and Iron Utilization Proteins in Virulence of the Fish Pathogen Flavobacterium columnare’.

Flavobacterium columnare causes columnaris disease in freshwater fish. The mechanisms responsible for columnaris disease are not known. F. columnare uses its type IX secretion system (T9SSs) to secrete enzymes, adhesins, and proteins involved in gliding motility. Deletion of a gene encoding a core component of this system eliminated virulence, suggesting that the secreted proteins may be virulence factors. F. columnare secretes two chondroitinases that digest chondroitin, a component of fish connective tissues. It also secretes a heme binding protein used for iron uptake. Iron acquisition from the host is important for virulence of many bacterial pathogens. We identified genes encoding siderophore synthesis proteins, outer membrane iron receptors, and components of an iron related cytoplasmic membrane ABC transporter. Rachel will discuss the roles of the T9SS, secreted chondroitinases and iron uptake systems in F. columnare virulence.

The presentation will begin at 4:00 PM via Microsoft Teams, preceded by an informal Q&A from 3:45 – 4:00 PM.