Characteristics of Pathogenic Fungi 323 



sec p. 253). Later, transplants ma) grow aerobically. Growth is m>l usual 

 with ever) attempt, so inoculation ol a number ol tubes is advisable. Sur- 

 face colonies are pasty hut ol variable consistency and configuration. There 

 is usually considerable pigment in the surrounding medium. Cultures 

 ol Actinomyces bovis almost always die quickly. 



■ttfli 



Fig. 92. Granule of Actinomyces present in tissue removed from a patient with maduro- 

 mycosis. (Courtesy of Wilbert Sachs.) 



(d) Culture mount.— Interlacing hyphae are present without any char- 

 acteristic spore forms. 



(e) Filtered ultraviolet rays.— The appearance is not distinctive. 



(f) Animal inoculation.— When cultural material is inoculated into 

 animals an infection develops in only about 50 per cent. The infection is 

 usually of minor importance and tends to heal spontaneously. This is inter- 

 esting in view of the fact that the disease is most likely identical in animals 

 and in human beings. 



(g) Differential diagnosis.— In the early stage of infection or when 

 the disease is untreated, it is usually easy to demonstrate' a typical granule. 

 Secondary infection may mask the true nature. Culturing is difficult, and 

 when no results are apparent from the direct mount or from attempts to 

 culture, animal inoculation should be undertaken. (See also the following 

 sections on S. schencki, B. dermatitidis and C. immitis. ) 



21. SPOROTRICHUM SCHENCKI 



The chief, if not the only, cause ol sporotrichosis in this countr) is prob- 

 ably a frequent saprophyte on main kinds of vegetation. 



