204 ESSENTIALS OF BACTERIOLOGY 



Stab-culture. Very profuse along the needle-track, in the 

 form of a cone after two days, the colonies having gathered at 

 the apex. 



Potato. A dirty gray, not very abundant, layer, somewhat 

 viscid. 



Staining. With ordinary methods; also Gram's method. 



Pathogenesis. If a pure culture is injected into the mammary 

 gland of sheep, a "mal de pis' 7 is produced which causes the 

 death of the animal in twenty-four to forty-eight hours. The 

 breast is found edema tous, likewise the thighs and perineum; 

 the mammae very much enlarged, and at the nipples a blue- 

 violet coloration. The spleen is small and black; other animals 

 are less susceptible. In rabbits abscesses at the point of infec- 

 tion, but no general affection. 



Bacillus Alvei (Cheshire and Cheyne) ; Bacillus melit- 

 tophtharus (Cohn) . Origin. In foul-brood of bees. 



Form. Slender rods, with round and conical pointed ends; 

 very large oval spores, the rod becoming spindle-shaped when 

 they appear. 



Properties. Motile, liquefying gelatin rapidly. 



Growth. Grows best between 20 C. and 37 C., very 

 slowly; aerobic. 



Gelatin Plates. Small grooves are slowly formed, which unite 

 so as to form a circle or pear-shaped growth, from which linear 

 grooves again start. 



Stab-culture. Grows first on surface, then gradually along 

 the needle-track, long processes shooting out from the same, 

 clouding the gelatin. Later, air-bubbles form like the cholera 

 culture, and in two weeks the whole gelatin liquefies. 



Staining. Do not take anilin dyes very well. Gram's 

 method is, however, applicable. 



Pathogenesis. If a pure culture is spread over the honey- 

 comb containing bee larvae, or if bees are fed upon infected 

 material, foul-brood disease will occur. Mice, if injected, die 

 in a few hours. Edema around the point of infection, and 

 many bacilli contained in the edematous fluid, otherwise no 

 changes. 



