CHROMOGENIC BACILLI IOQ 



representative of the large intestine flora. B. lactis acidi is less thermophilic than 

 B. acidophilus and coagulates milk which B. acidophilus does not do. Certain 

 polar granule bacteria, as B. granulosum, found in Yoghurt, are similar to B. acido- 

 philus but coagulate milk; no gas. B. bulgaricus is the type of the group and is 

 discussed under milk. 



Rodella thinks B. acidophilus, B. bifidus, B. gastrophilus and the Boas-Oppler 

 bacillus identical. B. bulgaricus is said to never show polar granules. B. bulgaricus 

 and the group of organisms similar to it found in buttermilk, etc., are widely used in 

 the treatment of various intestinal troubles. North has used cultures of B. bulgari- 

 cus for extermination of undesirable organisms in other parts of the body than the 

 alimentary canal (used as applications in nasal, throat or geni to-urinary infections). 



CHROMOGENIC BACILLI. 



These are identified by the color of their colonies on agar. The 

 B. pyocyaneus is the most important one of them in medicine, but the 

 B. prodigiosus is also of interest medically. A violet chromogen, the 

 B. violaceus, which is motile and liquefies gelatin, has been described 

 under many names. It has been found in water. 



An orange-yellow chromogen, the B. fulvus, is nonmotile and varies 

 as to its liquefaction of gelatin. 



B. pyocyaneus (Gessard, 1882). This organism is frequently 

 termed the bacillus of green or blue pus. It is a small (2.5X0.5/0 

 motile Gram negative bacillus. 



It is generally a slender delicate bacillus often showing thread-like 

 arrangement but at times it may appear as short plump rods. It 

 grows readily at room or incubator temperature. It liquefies gelatin 

 rapidly. The green color diffuses through the agar or gelatin on which it 

 grows, so that we not only have the green-colored colony, but the me- 

 dium as well is colored. Upon potato the colonies are more of a deep 

 olive green to dirty brown. 



No gas is produced in either glucose or lactose bouillon; blood-serum is digested, 

 the pitted surface showing a reddish-brown color. The protein ferment pyocyanase 

 has been used to remove diphtheritic membrane and for treatment of M. catarrhalis 

 nasal catarrhs. There are two pigments a green water soluble one and a blue 

 one soluble in chloroform. 



It is widely distributed in water and air, and is frequently isolated 

 from faeces. The B. fluorescens liquefaciens of water seems to be simply 

 a strain of B. pyocyaneus. The B. pyocyaneus is frequently associated 

 with other pus organisms in abdominal abscesses. 



