THE BACILLUS OF GUINEA-PIG PNEUMONIA 801 



By this method he was able to obtain results comparable in regularity 

 to guinea-pig inoculation, and obtained cultures in about four days 

 as against eight weeks by the guinea-pig inoculation. 



It is important in making routine guinea-pig injections of milk 

 for the determination of tuberculosis to remember the warning of 

 Theobald Smith 19 and not to jump at conclusions from mere gross 

 appearance at autopsy of the animals. 



Whether or not the presence of B. abortus in milk is a danger 

 to man is not certain, but it seems possible that the organism may 

 cause diarrheal and perhaps other diseases, and the milk of aborted 

 cattle should not be used for some time after abortion, and perhaps 

 subjected to bacteriological test. 



The striking similarity described by Evans and others of the 

 B. abortus of cattle and the B. melitensis, taken together with the 

 fact recently observed that other animals, especially the goat, may 

 be infected by the B. melitensis, suggests the possibility of human 

 pathogenicity for B. abortus, though at the present time this can 

 be mentioned merely as a conjecture and a subject for inquiry. 



Bacillus of Guinea-Pig Pneumonia. In 1914 Theobald Smith 20 

 called attention to a minute motile bacillus originally described by 

 Tartakowsky which he found to be the cause of epidemic pneumonia 

 in guinea-pigs. He found it to be similar to the organism described 

 by Strade and Traina as the B. pneumoniae caviarum and Selter's 

 B. caviae septicus. This organism he identified with the B. bron- 

 chisepticus of McGowan. 21 He describes the bacillus of guinea-pig 

 pneumonia as follows : 



It is a minute rod with rounded ends. From agar slants it 

 measures about 0.7 micron in length and about 0.5 micron broad. 

 Longer rods are occasionally seen. The organisms stain solidly and 

 are Gram-negative. They are rapidly motile. They grow moderately 

 well on gelatin at room temperature, but do not liquefy the gelatin. 

 On potato the bacillus makes a rich yellowish-brown color appearing 

 within a week. It clouds broth within twenty-four tours, making 

 a delicate iridescent membrane on the surface after prolonged growth. 

 Later, a ropy deposit appears. It makes no visible change on milk. 

 It does not produce indol. It is strictly aerobic and on sugar media 



19 Smith, Jour. Exper. Med., 30, 4, 325, 1919. 



- Smith, Theobald, Jour. Med. Res., 29, 1914, 291. 



21 McGowan, Jour. Path, and Baet., 15, 1910, 372. 



