178 PATHOGENIC BACTERIA 



the host may be assumed when infection occurs. It 

 may enter by cracks or wounds, and not infrequently 

 is associated with other bacteria, notably the pus cocci. 

 The pyocyaneus bacillus is an actively motile straight 

 or slightly curved, non-spore-forming rod measuring 

 from 2TTOTT inch to -goVo inch long and y-g-J-g- Q inch 

 wide. Its motility is due to one flagellum placed 

 at one end. 



FIG. 51 



Bacillus pyocyaneus. (From Kolle and Wassermann.) 



It grows readily at room or body temperature, best 

 in the presence of oxygen. On agar jelly it forms pig- 

 ments which color the growth itself and the medium 

 upon which it is living. These pigments are of two 

 kinds, a green one and a fluorescent one. They impart 

 a beautiful green fluorescence to the tube of culture 

 material. The bacillus has the power to elaborate a 

 gelatine-digesting and a milk-curdling ferment. Its 

 powers of resistance to heat and chemicals are rather 

 high. Materials to be disinfected should be exposed 



