566 Micro-organisms of the Plague Group 



(Fliigge), bacillus of "Wildseuche" (Hiippe), bacillus of "Buffelseuche" (Oriste- 

 Armanni), etc. 



Bacillus Suisepticus (Loffler and Schtjtz) 



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

 non-liquefying, non-chromogenic^ aerobic and optionally anaerobic bacillus, 

 pathogenic for hogs and many other animals, staining by the ordinary methods, 

 but not by Gram's method. It produces a slight acidity in milk, but does not 

 coagulate it. 



The bacillus of swine-plague, or BaciUus suisepticus of Loffler and Schiitz* and 

 Salmon and Smith,t but slightly resembles the bacillus of hog-cholera {q.v.), 

 though it was formerly confounded with it and at one time thought to be iden- 

 tical with it. The species have sufficient well-marked characteristics, however, 

 to make their differentiation easy. 



Swine-plague is a rather common and exceedingly fatal epidemic disease. It 

 not infrequently occurs in association with hog-cholera, and because of the lack 

 of sufficiently well-characterized S3anptoms — sick hogs appearing more or less 

 alike — is often mistaken for it. The confusion resulting from such faulty 

 diagnosis makes it difficult to determine exactly how fatal either may be in 

 uncomplicated cases. 



Morphology. — The bacillus of swine-plague much resembles that of chicken- 

 cholera. It is a short organism, rather more slender than the related species, 

 not possessed of flagella, incapable of movement, and producing no spores. 



It is an optional anaerobe. 



Staining. — The bacillus stains by the ordinary methods, sometimes only at 

 the poles, then closely resembling the bacillus of chicken-cholera. It is not 

 colored by Gram's method. 



Cultivation.— In general, the appearance in culture-media is very similar to 

 that of the hog-cholera bacillus. Kruse,t however, points out that when the 

 bacillus grows in bouillon the liquid remains clear, the bacteria gathering to 

 form a flocculent, stringy sediment. The organism does not grow upon ordi- 

 nary acid potato, but if the reaction of the medium be alkaline, a grayish-yellow 

 patch is formed. In milk a slight acidity is produced, but the milk is not 

 coagulated. 



Vital Resistance. — The vitality of the organism is low, and it is easily destroyed. 

 Salmon says that it soon dies in water or when dried, and that the temperature 

 for its growth must be more constant and every condition of life more favorable 

 than for the hog-cholera bacillus. The organism is said to be widely distributed 

 in nature, and is probably present in every herd of swine, though not pathogenic 

 except when its virulence becomes increased or the vital resistance of the animals 

 diminished by some unusual condition. 



Rabbits, mice, and small birds are very susceptible to the infection, usually 

 dying of septicemia in twenty-four hours; guinea-pigs are less susceptible, except 

 very young animals, which die without exception. Chickens are more immune, 

 but usually succumb to large doses. Hogs die of septicemia after subcutaneous 

 injection of the bacilli. There is a marked edema at the point of injection. If 

 injected into the lung, a pleuropneumonia follows, with multiple necrotic areas in 

 the lung. In these cases the spleen is not much swollen, there is slight gastro- 

 intestinal catarrh, and the bacilli are present everywhere in the blood. 



Animals can be infected only by subcutaneous, intravenous, and intraperi- 

 toneal inoculation, not by feeding. 



As seen in hogs, the symptoms of swine-plague closely resemble those of hog- 

 cholera, but differ in the occurrence of cough, swine-plague being prone to affect 

 the lungs and oppress the breathing, which becomes frequent, labored, and pain- 

 ful, while hog-cholera is chiefly characterized by intestinal symptoms. 



The course of the disease is usually rapid, and it may be fatal in a day or two. 



Lesions. — At autopsy the lungs are found to be inflamed, and to contain 

 numerous small, pale, necrotic areas, and sometimes large cheesy masses i or 



* "Arbeiten aus dem kaiserlichen Gesundheitsamte," i. 



t "Zeitschrift f. Hygiene,".x. 



tFlugge's "Die Mikroorganismen, 1896," p. 419. 



