Objective—To investigate the effects of sterile fine dust aerosol inhalation on antibody responses and lung tissue changes induced by Mucor ramosissimus or Trichoderma viride spores following intratracheal inoculation in goats.
Animals—36 weanling Boer-Spanish goats.
Procedures—6 goats were allocated to each of 2 M ramosissimus–inoculated groups, 2 T viride–inoculated groups, and 2 control (tent or pen) groups. One of each pair of sporetreated groups and the tent control group were exposed 7 times to sterilized fine feedyard dust (mean ± SD particle diameter, < 7.72 ± 0.69 μm) for 4 hours in a specially constructed tent. Goats in the 4 fungal treatment groups were inoculated intratracheally 5 times with a fungal spore preparation (30 mL), whereas tent control goats were intratracheally inoculated with physiologic saline (0.9% NaCl) solution (30 mL). Pen control goats were not inoculated or exposed to dust. Goats received an IV challenge with equine RBCs to assess antibody responses to foreign antigens. Postmortem examinations were performed at study completion (day 68) to evaluate lung tissue lesions.
Results—5 of 7 deaths occurred between days 18 and 45 and were attributed to fine dust exposures prior to fungal treatments. Fine dust inhalation induced similar lung lesions and precipitating antibodies among spore-treated goats. Following spore inoculations, dust-exposed goats had significantly more spores per gram of consolidated lung tissue than did their nonexposed counterparts.
Conclusions and Clinical Relevance—Fine dust inhalation appeared to decrease the ability of goats to successfully clear fungal spores from the lungs following intratracheal inoculation.
Objective—To compare the virulence of spores of 7
fungi by tracheal inoculation of goats following exposure
of goats to an aerosol of sterilized feedyard dust.
Animals—54 weanling Boer-Spanish goats.
Procedure—A prospective randomized controlled
study was conducted. There were 7 fungal treatment
groups, a tent control group, and a pen control group
(n = 6 goats/group). Goats in the 7 treatment and tent
control groups were exposed to autoclaved
aerosolized feedyard dust for 4 hours in a specially
constructed tent. Goats in the 7 treatment groups
were then inoculated intratracheally with 30 mL of a
fungal spore preparation, whereas tent control goats
were intratracheally inoculated with 30 mL of physiologic
saline (0.9% NaCl) solution. These treatments
were repeated each week for 6 weeks.
Results—Severity of pathologic changes differed significantly
among the 7 fungal treatment groups as
determined on the basis of gross atelectatic and consolidated
lung lesions and histologic lesions of the
lungs. Descending order for severity of lesions was
Mucor ramosissimus, Trichoderma viride,
Chaetomium globosum, Stachybotrys chartarum,
Aspergillus fumigatus, Penicillium chrysogenum, and
Monotospora lanuginosa. Trichoderma viride spores
were the most invasive and were isolated from the
bronchial lymph nodes and thoracic fluid of all 6 goats
administered this organism. Spores were observedhistologically
in lung tissues harvested 72 hours after
inoculation from all treatment groups.
Conclusions and Clinical Relevance—4 of 7 fungal
spore types induced significantly larger lung lesions,
compared with those induced by the other 3 spore
types or those evident in control goats. (Am J Vet Res 2005;66:615–622)