PATHOGENIC BACTERIA. 



119 



FIG. Gl. 



Properties. Without movement ; liquefying gelatine. It gives 

 rise to an orange-yellow pigment in the various cultures. 



Growth. It grows moderately fast at ordinary temperature, 

 and can live without air, a facultative serobin and anuerobin. 



Colonies on Gelatine. On second day small dots on the surface, 

 containing in their centre an orange-yellow spot. The gelatine 

 all around the colony is liquefied ; the size is never much greater 

 than that attained the second day. 



Colonies on Agar. The pigment remains a 

 long time. 



Stab Culture. At first, gray growth along 

 the track, which, after three days, has settled 

 at the bottom of the tube in a yellow granular 

 mass, the gelatine being all liquid. 



Stroke Culture on Agar. The pigment dif- 

 fused over the surface where the growth is, in 

 moist masses. 



Potato. A thin white layer which gradu- 

 ally becomes yellow and gives out a doughy 

 smell. 



Staining. Very readily colored with ordi- 

 nary stains ; also with Gram's method. 



Pathogenesis. When rabbits are injected 

 with cultures of this microbe into the knee- 

 joint or pleura, they die in a day. If injected 

 subcutaneously, only a local action occurs, 

 namely, abscesses. 



If directly into circulation, a general phleg- 

 monous condition arises, the capillaries become 

 plugged with masses of cocci, infarct occur in kidnej^ and liver, 

 and metastatic abscesses form in viscera and joints. Garre, by 

 rubbing the culture on his forearm, caused carbuncles to appear. 



Fracturing a long bone in an animal and then injecting the 

 staphylococcus into a large vein, as the jugular, will produce 

 osteomyelitis. Becker isolated this microbe from several cases 

 of osteomyelitis, and thought it a specific germ, giving it the 

 name of 4 ' micrococcus of osteomyelitis. " 



Suppuration is nearly always produced by this microbe, and 

 it is found in the majority of suppurative processes. 



Stab culture. Micro- 

 coccus pyogenes 

 aureus. 



