Bacillus Pyocyaneus 309 



Pathogenesis. The bacillus is pathogenic for the small 

 laboratory animals, but different cultures differ greatly 

 in virulence, i c.c. of a virulent bouillon culture, injected 

 into the subcutaneous tissue of a guinea-pig or a rabbit, 

 causing rapid edema, suppurative inflammation, and death 

 in a short time (twenty-four hours). Sometimes the animal 

 lives for a week or more, then dies. There is a marked 

 hemorrhagic subcutaneous edema at the seat of inoculation. 

 The bacilli can be found in the blood and in most of the 

 tissues. The guinea-pig is most susceptible. 



Doses too small to prove fatal sometimes lead to suppu- 

 ration, and the injection of sterilized cultures leads to simi- 

 lar results, a relatively larger quantity being required. 



Intraperitoneal injections cause purulent peritonitis. 



Blum * reports a case of pyocyaneus infection with endo- 

 carditis in a child. 



Lartigau, ( in his study of "The Bacillus Pyocyaneus as 

 a Factor in Human Pathology," sums up what is known 

 about this role of the organism as follows: "The Bacillus 

 pyocyaneus, like many pathogenic micro-organisms, is 

 occasionally found in a purely saprophytic role in various 

 situations in the human economy. It has been found in the 

 saliva by Pansini, in sputum by Frisch, and in the sweat by 

 Eberth and Audanard. Abelous demonstrated its presence 

 in the stomach as a saprophyte. Its existence in suppurat- 

 ing wounds has long been known, and Koch early detected 

 its presence in tuberculous cavities, regarding it as an 

 organism incapable of playing any pathologic role. The 

 etiologic relation of the organism to certain cases of purulent 

 otitis media in children was pointed out by Martha, Mag- 

 giora and Gradenigo, Babes, Kossel, and others. H. C. 

 Ernst obtained it from a pericardial exudate during life. G. 

 Blumer demonstrated its presence in practically pure cul- 

 tures in a case of acute angina simulating diphtheria; 

 Jadkewitsch, B. Motz, and Le Noir obtained the bacillus 

 in cases of urinary infection. The cases of Triboulet, 

 Karlinski, Oettinger, Ehlers, and Barker are interesting 

 instances of its role in cutaneous lesions. 



"In addition to these lesions, other morbid processes 

 have been associated in some cases with the bacillus of 

 blue pus, such as meningitis and broncho-pneumonia by 



: "Centralbl. f. Bakt. u. Parasitenk.," Feb. 10, 1899, xxv, No. 4. 

 t "Phila. Med. Jour.," Sept. 17, 1898. 



