3 24 Suppuration 



of dead bacteria. The organism thus produces both endo- and 

 exotoxins. 



Pathogenesis.^ — ^The bacillus is pathogenic for the small laboratory 

 animals, but different cultures differ greatly in virulence. One 

 cc. of a virulent bouillon culture, injected into the subcutaneous 

 tissue of a guinea-pig, causes rapid edema, suppurative inflamma- 

 tion, 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. 

 Rats and mice behave similarly to guinea-pigs when inoculated 

 subcutaneously. 



Rabbits are less susceptible and subcutaneous injections rarely 

 cause death. Intraperitoneal injection may be followed by fatal 

 infection if the bacillus be highly virulent or if it be not virulent, 

 recovery may occur. Intravenous inoculation causes fever, al- 

 buminuria, diarrhea and death in a day or two. If the dose be 

 smaller or the virulence of the culture less, a subacute disturbance 

 characterized by wasting, palsy and convulsions may occur. If 

 the animal dies, nephritis can usually be found, and perhaps explains 

 the symptoms. 



Dogs are susceptible to infection by B. pyocyaneus, the symptoms 

 bearing a considerable resemblance to rabies. 



Blum* reports a case of pyocyaneus infection with endocarditis 

 in a child. 



Lartigau,t 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 occasion- 

 ally found in a purely saprophytic r61e 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 pres- 

 ence in the stomach as a saprophyte. Jts existence in suppurating 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 otiti? 

 media in children was pointed out by Martha, Maggiora 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 cultures 

 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, 

 ICarlinski, Oettinger, Ehlers, and Barker are interesting instances of its r61e 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 bronchopneu- 

 monia, by Monnier; diarrhea of infants, by Neumann, Williams, Thiercelin and 

 Lesage, and other observers; dysentery, by Calmette and by Lartigau; and 

 general infection, by Ehlers, Neumann, Oettinger, Karlinski, Monnier, Krannhals, 

 Calmette, Finkelstein, and L. F. Barker." 



Nine additional cases of human infection are reported by Perkins. J 



* "Centralbl. f. Bakt. u. Parasitent.," Feb. lo, 1899, xxv. No. 4. 



t "Phila. Med. Jour.," Sept. 17, 189.8. 



t "Jour, of Med. Research," 1901, vol. vi, p. 281. 



