CHAPTER VII. 



STUDY AND IDENTIFICATION OF BACTERIA. MYCO- 



BACTERIA AND CORYNEBACTERIA. KEY 



AND NOTES. 



Key for Bacilli. Having branching characteristics, as shown by 

 parallelism, branching, curving forms, V-shapes, clubbing at ends, seg- 

 mental staining, etc. 



/ Cultures more or less wrinkled and dry. 

 Acid-fast. Mycobactermm. \ ,, 



(^ More like moulds. 



I. Grow rapidly on ordinary media at room temperature. 



Examples: Timothy grass bacillus of Moeller (B. phlei). 



Mist bacillus. Butter bacilli as reported by (i) Rabinowitsch 

 and (2) Petri. 



II. Only grow at about incubator temperature. Scanty growth or none at all 



on ordinary media. Media of preference are: (a) solidified blood-serum, 

 (b) glycerine agar, (c) glycerine potato and (d) egg media. 



1. Cultures fairly moist, luxuriant, and flat. Op. temp. 43 C. 

 a. Bacillus of avian tuberculosis. 



2. Cultures scanty, wrinkled, and dry. Appear in ten to fourteen days. Op. 

 temp. 38 C. Bacilli longer, narrower, more regular in outline and staining 

 than bovine; vacuolation more marked (2.5^). Smear from organs of 

 inoculated guinea-pig shows few bacilli. Less virulent for rabbits. 



a. Bacillus of human tuberculosis. 



Cultures as above, but even more scanty. Bacilli shorter, thicker, less 

 vacuolated (1.5^). Smear from organs of guinea-pig shows many bacilli. 



b. Bovine tubercle bacilli. 



3. Very difficult to cultivate (Czaplewski). 

 Smegma bacilli of various animals. 



III. Noncultivable by ordinary methods. Cultivable in symbiosis with amoebae. 

 (Clegg.) Duval cultivated an acid-fast bacillus on N.N.N. medium con- 

 taining i% glycerine. Bayon cultivated on placental juice glycerine agar a 

 slightly acid-fast diphtheroid which changed to acid fast in peritoneum of 

 mouse. Bayon's organism thought to be similar to Kedrowsky's diphtheroid 

 of leprosy. 



i. B. leprae. Found chiefly in nasal mucus and in juice from lepra tubercles. 

 Less often in nerve leprosy. 



