Characterization of Bovine Pneumonia using Bacterial Culture, Immunohistochemistry, and PCR, The

Bovine Respiratory Disease (BRD) is a leading cause of economic losses in the beef industry worldwide, and accounts for a majority of deaths in pre-weaned cattle after 3 weeks of age. The term is used to encompass pneumonia in cattle caused by infectious agents and environmental conditions resulting in complex pulmonary lesions. Infectious causes include both bacterial and viral agents, with current models of pathogenesis suggesting a viral infection or period of stress followed by secondary infiltration of several bacterial species. The major bacterial organisms contributing to the development of this complex are Manheimia haemolytica, Histophilus somni, Mycoplasma bovis, Pasteurella multocida, and Trueperella pyogenes. All of these organisms may be present in healthy cattle populations, but can infiltrate the lungs to cause pneumonia following changes in environmental conditions, or infection by viral agents. Little work has been done to definitively characterize the complex relationships between bacterial species commonly indicated in cases of BRD. The goal of this project is to examine potential co-infection of lungs with H. somni and M. bovis using PCR, and to examine localization of these colonies in lesions by utilizing an Immunohistochemistry (IHC) staining technique as a comparison to traditional cell culture techniques for detection. By better characterizing the nature of complex infections, and developing more specific methods of detection, the cattle industry will be able to better understand and treat BRD.