SYMPTOMS 97 



bovisepticum . A brief description of the organism as given by 

 Wilson and Brimhall is appended. 



"The organism has a strong tendency to show polar staining in tis- 

 sues and to form chains of much shortened individuals in liquid media, 

 which causes it to be mistaken in examinations of a single specimen for 

 a diplococcusora streptococcus. Sometimes in cover-glass preparations 

 from solid organs and very frequently in those from body fluids and 

 liquid cultures, the bacteria were found in chains of three to twelve 

 individuals. In cover-glass preparations the bacteria are from o.6// to 

 o.8/( broad and from i.o to 1.5/i in length. In tissues which have been 

 fixed in 96 per cent, alcohol, they are somewhat smaller. In cultures, 

 especially in fluid media, they are apt to be much smaller and approach 

 diplococci in appearance. The ends are rounded. In stained prepara- 

 tions directly from the tissues most of the bacteria have the ends 

 intensely stained and the central portion but faintly so. In some chains 

 in rapidly growing broth cultures this is not the case, many of the indi- 

 vidual bacteria being evenly stained throughout and somewhat pointed 

 at the ends. They do not retain the stain by Gram's method. The 

 organism is non-motile. It is aerobic, but prefers the depths rather 

 than the surfaces of the media. It grows best at the body temperature 

 and more slowly at room temperature. In plain and dextrose broth a 

 growth appears in 24 hours. In Dunham's solution a small amount of 

 indol is formed in 48 hours. No coagulation of milk. On Loffler's 

 blood serum, direct from the diseased tissues, it failed to grow well. On 

 potato no appreciable growth has been obtained. In gelatin plates 

 small, granular, white to slightly yellowish colonies appear after 48 

 hours. In gelatin stab cultures a light growth occurs on the surface, 

 while along the needle tract numerous colonies like those in the deep 

 portions of the plate cultures develop. The bacteria are destroyed in 

 fluids at 58° C. in 7 or 8 minutes, by i to 5,000 mercuric chloride in one 

 minute, and by a solution of lime water as weak as 0.04 per cent, 

 almost immediately. ' ' 



The period of incubation is supposed to be very short. 

 The method of infection is not knovsrn. 



§81. Symptoms. There is little opportunity to deter- 

 mine the symptoms. The animals observed at the onset of the 

 disease by Wilson and Brimhall appeared to be dumpish and 

 out of sorts. There is sudden stopping of the milk secretion in 

 milch cows. As a rule the affected animals refuse food. Of 

 the few that make an attempt to eat, those with affected throats 

 are unable to swallow except with much difBculty. These 



Digitized by Microsoft® 



