Bacilli Resembling the Typhoid Bacillus 665 



ability to produce infection when ingested, and by the fact "that it elaborates a 

 toxic substance capable of producing symptoms similar to those seen in the 

 infection. 



Bacillus F^calis Alkaligenes (Petruschky) 



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

 fying, non-chromogenic, non-aerogenic, aerobic and optionally anaerobic, non- 

 pathogenic bacillus of the intestine, staining by ordinary methods, but not by 

 Gram's method. 



This bacillus has occasionally been isolated by Petruschky* and others from 

 feces. It closely resembles the typhoid bacillus, being short, stout, with round 

 ends, forming no spores, staining with the usual dyes, but not by Gram's method, 

 being actively motile, and having numerous flagella. It does not liquefy gelatin, 

 does not coagulate milk, produce gas, or form indol. Its pathogenic powers for 

 the lower animals are similar to those of the t5rphoid bacillus. 



It grows more luxuriantly than the typhoid bacillus upon potato, producing a 

 brown color, and generates a strong alkali when grown in litmus-whey. Its cul- 

 tures are not agglutinated by the typhoid serums. 



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, f 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 spe- 

 cific organism. 



The subsequent work of Gilbert and Fournierf 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 cultures, 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 immediately 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 injectedin the 

 ear- vein of a rabbit kill it in from twelve to eighteen hours. Guinea-pigs are 

 more resistant. Subcutaneous injection of dogs produces a hard, painful swell- 

 ing, which persists for a short time and then disappears without suppuration. It 

 is also infectious for man, a number of epidemics of peculiar pneumonia, charac- 

 terized by the presence of the bacillus in the blood, traceable to diseased parrots, 

 having been reported. 



Differentiation. — Bacillus psittacosis can best be differentiated from the ty- 

 phoid and the colon bacilli and others of the same group by its pathogenesis and 



* "Centralbl. f. Bakt. u. Parasitenk.," xk, 187. 



t" Seance du Conseil d'hygiene publique et Salubrite du Department de la 

 Seine," March 24, 1893. 



f'Comptes rendu de la Societe de Biologie," 1896; "LaPresse medicale," 

 Jan. 16, 1897. 



