530 Bacilli Resembling the Typhoid Bacillus 



BACILLUS PSITTACOSIS (NOCARD). 



General Characteristics. A motile, flagellated, non-sporogenous, 

 aerobic, optionally anaerobic, non-chromogenic, aerogenic, pathogenic, 

 non-liquefying bacillus, staining by the ordinary methods, but not 

 by Gram's method. 



This micro-organism was discovered by Nocard,* who first 

 observed it in 1892 in certain cases of psittacosis, or epidemic 

 pneumonia traceable to infection from diseased parrots. The 

 original paper contained an excellent account of the specific 

 organism. 



The subsequent work of Gilbert and Fournier f shows the 

 specificity of the micro-organism to be quite well established 

 and Nocard 's characterizations accurate. 



Morphology. The bacillus is short, stout, rounded at 

 the ends, and actively motile. It is provided with flagella, 

 but forms no spores. It resembles the typhoid and the 

 colon bacilli and is evidently a form intermediate between 

 the two. 



Isolation. Gilbert and Fournier succeeded in isolating 

 it from the blood of a patient dead of psittacosis, and from 

 parrots by the use of lactose-litmus-agar. The organism 

 does not alter the litmus, and if a small percentage of carbolic 

 acid be added to the culture media, it grows as does the 

 typhoid bacillus. 



Cultivation. The colonies, agar-agar and gelatin cul- 

 tures, closely resemble those of the typhoid fever organism. 

 Upon potato it more closely resembles the colon bacillus. 

 Bouillon becomes clouded. 



Metabolic Products. In bouillon containing sugars the 

 micro-organism is found to ferment dextrose, but not lactose. 

 Milk is not coagulated and not acidulated. No indol is 

 formed. 



Pathogenesis. Bacillus psittacosis can be immedi- 

 ately differentiated from the typhoid and colon bacilli by 

 its peculiar pathogenesis. It is extremely virulent for 

 parrots, producing a fatal infection in a short time. White 

 and gray mice and pigeons are equally susceptible. Ten 

 drops of a bouillon culture injected in the ear- vein of a rabbit 



* Seance du Conseil d'hygiene publique et Salubrite du Departe- 

 ment de la Seine, March 24, 1893. 



t "Comptes de la Societe de Biologic," 1896; and "La Presse 

 medicale," Jan. 16, 1897. 



