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Infant animal model of pulmonary mycotoxicosis induced by Stachybotrys chartarum.

Authors :
Yike I
Miller MJ
Sorenson WG
Walenga R
Tomashefski JF Jr
Dearborn DG
Source :
Mycopathologia [Mycopathologia] 2002; Vol. 154 (3), pp. 139-52.
Publication Year :
2002

Abstract

In recent years cases of often fatal pulmonary hemorrhage in infants have been associated with water damaged homes and the toxigenic fungus Stachybotrys chartarum. The fungal spores contain mycotoxins which could be injurious to the rapidly developing lung. In order to understand the developmental pathophysiology of this disease we developed an infant rat model of stachybotrytoxicosis describing the effects of fungal spores on survival, growth, histopathology of the lung and respiration. Conidia of S. chartarum were instilled intratracheally (1.0-8.0 x 10(5)/gm wt.) in 4-d old Sprague-Dawley rat pups. Two control groups received either sterile PBS or a suspension of spores extensively extracted with ethanol to remove toxins. Lethal dose response was determined (LD50 = 2.7 x 10(5) spores/gm wt.). All dead pups had extensively hemorrhagic lungs. Growth of surviving animals was impaired in a dose-dependent manner. Changes of pulmonary function parameters in rats treated with 1.1 x 10(5) spores/g were consistent with an increased respiratory resistance. Histology of lungs revealed fresh hemorrhage, sparse hemosiderin-laden macrophages, and evidence of inflammation including thickened alveolar septa infiltrated by lymphocytes and mononuclear cells and intra-alveolar macrophages. Significant increases (p = 0.001) in numbers of macrophages (2-fold), lymphocytes (5-fold) and neutrophils (7-fold) were found in BAL fluid. Hemoglobin was elevated 2-fold (p = 0.004). Proinflammatory mediator IL-1beta increased more than 6-fold and TNF-alpha 30-fold (p = 0.001). Extracted spores had a minimal effect on all examined parameters in BAL fluid indicating that mycotoxins are primarily responsible for the hemorrhagic and inflammatory response.

Details

Language :
English
ISSN :
0301-486X
Volume :
154
Issue :
3
Database :
MEDLINE
Journal :
Mycopathologia
Publication Type :
Academic Journal
Accession number :
12171446
Full Text :
https://doi.org/10.1023/a:1016098331428