PSEUDOMONAS PYOCYANEUS /I 



EXERCISE XXXI 



PSEUDOMONAS (BACILLUS) PYOCYANEUS 



112. Pseudomonas pyocyaneus, commonly known as the 

 bacillus of green pus, blue pus, or blue-green pus, is quite 

 widely distributed in nature. While ordinarily it has been 

 considered of little pathogenic importance, it is known to pos- 

 sess at times, and under certain conditions, marked infecting 

 powers. This organism has been called the honey bacillus, on 

 account of the peculiar odor emitted from its cultures. It is 

 to be differentiated from B. fluorescens liquefaciens and its vari- 

 eties which frequently appear in water. 



References. — Chapters on this organism in text-books. 

 Barker, The Clinical Symptoms, etc. The Jour, of the Am. Med. 

 Asso., July 31, 1897. Lartigau, Study of Pathogenesis, etc., Jour, of 

 Exp. Med., 1898, p. 595. Jordan, Pigments produced by. Ibid., 

 1899, p. 627. Rizicka, Arch, fur Hygiene, Bd. XXXIV., S. 149, 

 and Bd. XXXVIL, S. i. 



113. Work for this Exercise Examine very carefully and 



describe fully the cultures of Pseudomonas pyocyaneus made 

 during the last exercise. 



Make and examine a hanging-drop and a stained cover-glass 

 preparation from each of the bouillon and agar cultures. 



Describe the appearance of the bacteria in each. 



Measure and make a drawing of a few organisms in the 

 preparation from the agar culture. Magnify 500 diameters. 



Reexamine the cultures of the streptococcus and the micro- 

 coccus studied at the last exercise and note all appreciable 

 changes which have taken place. 



Inoculate a tube of each of the media in Groups A and D, 

 a tube of litmus milk, and one of sugar-free bouillon from a 

 culture of B. colt communis (furnished), for study at the next 

 exercise. 



