Degree Type


Date of Award


Degree Name

Master of Science


Veterinary Microbiology and Preventive Medicine

First Advisor

Bryan H. Bellaire


Brucella spp. are host specific facultative intracellular pathogens. Brucella abortus is responsible for causing abortions in cattle and is also able to cause disease in humans. Brucella internalization and intracellular trafficking varies depending on whether the bacterium was opsonized or non-opsonized with serum immunoglobulin. Interferon-gamma has been shown to be critical for the control of B. abortus infection in vivo and in vitro. A family of host Immunity-Related p47 guanosine triphosphate-binding proteins (GTPase) induced by IFN-gamma has been identified that are important for host defense against many intracellular pathogens such as M. tuberculosis, T. gondii , and L. monocytogenes . In these studies it was found that LRG-47 is required for Brucella survival and replication. Autophagy is a process in the cell whereby damaged proteins and organelles are broken down so their contents can be reused. In the following studies, an autophagosome-like extracellular organelle has been identified that is released by RAW264.7 murine macrophages in normal growth conditions and in conditions to induce autophagy. We have observed B. abortus using the natural intercellular trafficking pathway of the autophagosome-like extracellular organelle to infect a new host cell while evading the host immune system.


Copyright Owner

Jennifer Ann Ritchie



Date Available


File Format


File Size

109 pages