Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 7/19/2002
Publication Date: 11/10/2002
Citation: Purdy, C. W., Layton, R. C., Straus, D. C., Ayers, J. R. Intratracheal infusion of common feedyard fungi in goats. Proceedings of the 83rd CRWAD meetings. 2002. Paper No. 146. Interpretive Summary:
Technical Abstract: The objective of the study was to compare the pathology induced by four fungi compared to a saline control. Thirty weanling goats were randomly assigned to 5 groups, 6 goats per group. Four fungi (Aspergillus fumigatus, Penicillium chrysogenum, Mucor ramosissimus, and Montosporium lanuginosa ) isolated from cattle feedyards were each grown on malt agar extract. Eighteen culture Petri plates of each fungus were grown for spores. Each culture plate was washed with 10ml of saline, and the spores were twice passed through a 106 m sieve. Total spores were counted in a hemacytometer and the viable spores were counted by culturing colony forming units on malt agar extract plates (10-1 through 10-5 dilutions) in triplicate. A 30ml dose of spore suspension was infused orally through a pipette into the trachea of a lightly anesthetized goat. Thirty ml of saline was similarly administered to each goat in the control group. The tracheal infusions were repeated every other week for 6 treatments, and then the goats were euthanized. Three of the 4 fungi gave a significant (P 0.05) mean fever and mean leukocytosis response compared to the controls (the exception was M. lanuginosa). Histopathologic lung lesions of principal goats were patchy atelectatic areas with airway exudation of neutrophils and macrophages containing fungal spores, and increase in periairway associated lymphoid tissue. Mucor also induced giant cells, patchy fibrosis and granuloma formations. Random principal goat lung tissue sections stained with Gomori's methenamine silver had fungal spores and hyphae observed in goats inoculated with Aspergillus and Mucor. Mucor and Aspergillus were more pathogenic in goat lungs than Penicillin and Montosporium compared to the controls.