94 STUDY AND IDENTIFICATION OF BACTERIA 



human T. B. Nocard, by inserting collodion sacs containing bouillon 

 suspensions of human T. B., claims to have changed these to the avian 

 type. The avian type grows at 43C. fairly luxuriantly, as a moist, 

 more or less spreading culture. It grows much better on glycerinated 

 agar than on serum. Morphologically they are like the human type, 

 but show less tendency to form compact masses. Very pleomorphic. 

 Have been reported from sputum of man (doubtful). 



Fowls become infected by intravenous or subcutaneous injection or as the result 

 of feeding. After feeding the lesions are chiefly of the alimentary tract; after in- 

 jections, of spleen, liver and lungs. Avian T. B. is more virulent for rabbits than 

 human T. B. but less so than bovine T. B. The mouse is the only animal besides the 

 rabbit in which avain T. B. can cause a generalized tuberculosis. The conclusions 

 are that there is no danger to man from avian T. B. With the bovine type it is 

 quite different as nearly one-half of the deaths in young children from abdominal 

 tuberculosis were due to bovine T. B. and to that type alone. Not only in children, 

 but in adolescents suffering from cervical gland tuberculosis, a large proportion were 

 caused by bovine types. The bovine type is also an important factor in lupus. 



There is also a fish tuberculosis. This organism grows much more 

 rapidly than the other types (three to four days), and grows best at 

 24C., growth ceasing at 36C. The colonies are round and moist. 



It is certain that many of the symptoms usually noted in the tuberculous are due 

 to secondary infections. Pettit, by careful blood cultures, obtained the Pneumo- 

 coccus in 24 cases and the Streptococcus in 36 cases out of 130 cases studied. He 

 used from 5 to 20 c.c. of blood from the vein. Positive blood cultures were obtained 

 in 68% of far-advanced cases, 45% of advanced cases and 16% of incipient cases. 



The best culture medium for primary cultures is blood-serum or, 

 better, a mixture of yolk of egg and glycerine agar. Petroff 's medium 

 and Dorsett's egg medium are also used. In subcultures, either glycer- 

 ine agar, glycerine potato, or glycerine bouillon make good media. 



In inoculating media from tuberculous material, as, say, from a tuberculous gland 

 or, more practically, from the spleen of a guinea-pig, the material must be thoroughly 

 disintegrated or rubbed on the surface of the media so that individual bacilli may 

 rest on the surface of the culture media. In growing in flasks in glycerine bouillon 

 a surface growth is desired. The cylindrical flask of Koch gives a better support 

 to the pellicle than an Erlenmeyer one. In inoculating, a scale of such a surface 

 growth or a grain from the growth on a slant should be deposited on the surface of 

 the glycerine bouillon in the flask. In cultivating from sputum use Petroff's 

 medium. 



Inasmuch as the filtrate from cultures has little toxic effect, the 

 poison is assumed to be intracellular. 



