Interactions between natural products and pathogenicity in Yersinia ruckeri

Supervisors:

• Dr Hai Deng (MBC)
• Professor Chris Secombes (SBS)

Full time PhD student:

• Andrew Beggs (2012-2018)

Y. ruckeri is the causative agent of the disease Enteric Redmouth Disease (ERM) in Salmonids, particularly in farmed Salmon and Trout. This disease is economically significant as outbreaks can lead to large loss of stock.

The pathogenicity of a pathogen is defined by the ability of the pathogen to infect the host. This pathogenicity is measured by virulence, and is related to the host-pathogen interactions, which in turn can be related to the secondary metabolites produced by the pathogen. Such natural products are termed virulence factors.

Virulence factors produced by an organism can be investigated by metabolic profiling, in which numerous chromatographic and analytical techniques are employed to isolate and identify the secondary metabolites produced by the organism in varying conditions. An advantage of metabolic profiling is that it can provide an unbiased snap shot of the behaviour of an organism in a particular environment.

Several virulence factors and proposed virulence factors have been identified for Y. ruckeri. They include:

• Ruckerbactin (An iron binding compound or siderophore)
• A haemolysin protease Yrp1
• The proposed virulence factor holomycin (An antibiotic)

This project will be based on the following aims:

• To identify secondary metabolites from bacteria, using analytical methods and metabolic profiling
• To identify virulence factors produced by Y. ruckeri in order to understand its modes of infection
• To determine whether identified secondary metabolites are virulence factors, and their activity in fish and fish cell lines
• Investigating the action of potential treatments against Y. ruckeri