142 Mycotic Pneumonia. 



8. Mycotic Pneumonia. Pneumonomycosis. 



{Pneumonomycosis asperglUbia.) 



Etiology. Moulds in the air passages are found most 

 frequently in places where the temperature is somewhat lower 

 and where fungi can remain permanently in contact with the 

 air. They also form larger colonies in the presence of more 

 ahnndant masses of secretion or decomposition products. One 

 finds colonies of moulds in bronchiectasias, pulmonary cavities, 

 exceptionally in bronchial catarrh. In all of these cases, how- 

 ever, moulds live in the interior of the air passages onh" as 

 saprophytes without attacking the living tissues and without 

 producing pathologic changes in them (secondary mycosis). 



Only rarely can disease of the air passages be referred 

 directly to a pathogenic effect of moulds (primary or true 

 mycosis). This appears to be the case after the inhalation 

 of very great amounts of moulds. Moulds may display a 

 pathogenic effect preferably in weakened individuals and in 

 the presence of a catarrhal affection of the lungs. Schultz 

 produced the disease artificially in birds by inhalation. Accord- 

 ing to Folger, mould spores may also get into the lungs by 

 embolic transport. 



Most common of the pathogenic moulds are species of 

 aspergillus, especially aspergillus fumigatus and aspergilhis 

 nigrescens. The former still grows well at a temperature 

 of 37°-40° C. ; the latter at 37° C. ; hence aspergillus fumigatus 

 is considerably more dangerous (Schultz, Lucet). Aspergillus 

 glaucus does not grow at body temperature and only forms 

 larger colonies perhaps in the larger air passages, but it can- 

 not penetrate into the tissues. Some species of mucor grow 

 at 40° C. and also in the interior of animal tissues. 



Tlie species of aspergillus form a colorless mycelium, from which arise straight, 

 11011- branehiug hyphae; these end free in a globular swelling, the columella, which 

 carries numerous radially arranged sterigma^, from which a single row of conidia 

 is formed by constriction, which, in combination with the sterigmaj and the columella 

 form the fruit -headlet {Fig. 19). The following species are pathogenic: 



Aspergillus fumigatus forms at the beginning bluish-green, later on ashy-gray 

 colonies. The diameter of the semispherical or club-shaped columella is 8 to 20 ^u; 

 of the conidia 2 to 3 ytt. The sterigmge rise more or less upward. 



Aspergillus nigrescens (asp. iiiger.) columella spherical and carries pure 

 ra<lially arranged sterigmaB, with blackish conidia. The mycelium therefore looks 

 chocolate colored. 



Aspergillus glaucus; the hypha % to 1 mm. long possesses a club-shaped 

 columella with radially arranged sterigniEe. The segmented conidia are grayish-green, 

 the mycelium is of the same color (Fig. 19). 



Characteristic of Penicillia (brush-moulds) is an umbilliferous arrangement 

 of the conidia bearers, which terminate in bottle-shaped cells, each one of which 

 carries a chain of conidia (Fig. 20). Pathogenic penicillia have so far not been 

 found in domestic animals. 



The fruit bearer in Mucorinae terminates in a spherical brown or black 

 sporangium containing the spores. After rupture of the smooth membrane these 

 escape into the outside world (Fig. 21). Mucor racemosus and mucor conoideug 

 have heretofore been found in the air passages. 



