Date of Award

Fall 2007

Project Type


Program or Major


Degree Name

Master of Science

First Advisor

W Relley Thomas


A major goal of modern biology is to extend our understanding of biological systems investigated in the laboratory to their ecological and evolutionary context. With extensive understanding of the function, development and genetics of C. elegans, exploring the link between this laboratory model and the environment in which this system evolved would be very interesting because very little is known about the natural history of this premier model organism.

A new strain of Caenorhabditis briggsae (SoAf) with an associated bacterium, Serratia sp. SCBI, has been isolated from South Africa using common entomopathogenic nematode trapping methods. This study taxonomically identified and evaluated entomopathogenic behavior of C. briggsae SoAf and Serratia sp. SCBI. Hemocoelic injections of Serratia sp. SCBI demonstrated pathogenicity in insect larvae, Galleria mellonella. Caenorhabditis briggsae SoAf and other Caenorhabditis, including C. elegans , were capable of infection, growth and reproduction within the insect larvae in the presence of Serratia sp. SCBI. Identification of a putative entomopathogenic C. briggsae expands on our understanding of Caenorhabditis ecology and provides a framework for further investigation of entomopathogensis in other free-living nematodes.