VACCINE-THERAPY 45 



Streptothrix Actinomycosis Boris. 



Biological Chaeacters. — 1. On broth the medium is not 

 coloured, but grey masses settle at tiie bottom. 



2. On gelatin plates in a week a yellow growth develops. 



3. In gelatin stab firm outgrowths take place, with slight 

 liquefaction. 



4. On agar opaque colonies grow. 



5. On glycerine agar, at 37° C, in three or four days 

 appears a yellow growth, tinged with red, adhering firmly 

 to the medium. 



6. On potato colonies form of a yellow colour, tinged with 

 red, and look as though covered with fine hair. 



Staining. — By Gram's method and methylene violet. 



Microscopical Appearances. — If from pus note filaments 

 and spores (Gram-positive). Clubs round periphery of 

 colony, radiating from the centre (Gram-negative). 



It is anaerobic and facultatively aerobic. 



(b) Gram-Negative — Bacillus Mallei. 



Biological Characters. — 1. In broth a diffused cloudiness 

 takes place, ultimately developing into a tenacious sedi- 

 ment. 



2. On glycerine agar a moist opaque layer is formed. 



3. On potato a characteristic growth at 37° C. takes place, 

 at first amber in colour, and later developing into a reddish- 

 brown. 



Staining. — Young cultures stain readily with the ordinary 

 aniline dyes. 



Microscopical Appearances. — The bacillus is a short rod, 

 usually straight, but sometimes curved. They are usually 

 single, rarely in pairs or short chains. 



Involution forms are frequently produced; clubs, filaments, 

 and even branches have been noted. 



This is a facultative bacillus growing with or without 

 oxygen. Minimum temperature, 25° C. ; optimum, 37° C. ; 

 maximum, 42° C. 



