CHAPTER X 
ASPERGILLOSIS AND FAVUS 
ASPERGILLOSIS 
Synonyms. Pneumo-mycosis, brooder pneumonia. 
Characterization. Aspergillosis is a disease of the pulmonary 
region due to infection with fungi. It is characterized by the form- 
ation of an exudate, usually of a moldy appearance, on the mucous 
membrane of the air passages, principally the air sacs of the ab- 
dominal cavity. 
Etiology. The disease is almost invariably introduced by fungi 
of the genus Aspergillus, Aspergillus fumigatus being the most con- 
stant causative agent. Other members of the aspergillus group have 
been identified in the morbid processes. These, however, are of 
slight significance as they have not been associated with the incidence 
of pulmonary mycosis to any great extent. 
Aspergillus fumigatus is widely distributed in nature and is often 
observed on vegetable matter of all kinds which has been exposed 
to dampness. Birds scratching 
among moldy grains or in moldy 
litter may inhale the spores. 
These find a favorable place for 
propagation on the mucose of the 
bronchi, or of the air sacs. 
The fungus may be readily 
grown on potato, rye bread or 
plain agar which is acid in reac- 
tion. The most suitable temper- 
ature is between 35° and 40° C. 
The growth appears after 24 
hours incubation as a whitish 
downy layer over the surface of Fic. 10. Aspergillus fumigatus. 
the medium. This is composed aoe from Mohler and Buck- 
of an interwoven mass of trans- ov 
parent mycelial threads which later give off branches capped by fruit 
heads. Each of the latter is composed of a mass of small rounded 
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