CULTURAL PROPERTIES 299 



lining of the interior of the heart is frequently found. The valves 

 are covered with fibrinous and hemorrhagic wart-like deposits, and 

 scattered ulcerations are seen. This is a pathologic change known 

 as endocarditis verrucosa and ulcerosa. The specific bacillus causing 

 the disease occurs in moderate numbers in the blood and in larger 

 numbers in the spleen, liver, and kidneys, and the verrucous deposits 

 in the heart. 



Morphology and Staining Properties. The Bacillus rhusiopathise suis, 

 or bacillus of swine erysipelas, can be best seen in preparations made 

 from the juice of the spleen, liver, or kidneys of swine just dead from 

 the disease or killed during its last stages. It is a very small, slender 

 bacillus, only 1 to 1.5 micra long; it occurs singly and in small 

 groups, sometimes in chains which are wavy or angular in outline. 

 Such chains are particularly clearly seen in the endocardial verrucous 

 deposits, which may contain the organisms in very large numbers. 

 The bacillus stains with the ordinary watery anilin stains, and is Gram 

 positive. The latter stain shows the bacilli particularly well in blood 

 smears, or smears from the organs mentioned, in which it is found 

 in larger numbers or in sections of tissues. The bacillus is not motile, 

 possesses no flagella, and forms no spores. 



Cultural Properties. The organism grows well at room and at 

 incubator temperatures. It grows well in a very characteristic manner 

 in gelatin as first described by Loeffler, Schiitz, and Schottelius. On 

 gelatin plate cultures inoculated from spleen juice or blood, hazy, 

 bluish-gray, racemose, cloudy spots appear on the second or third 

 day; they are situated a little below the surface of the medium, and 

 can only be seen with some difficulty if the plate is placed on a dark 

 background. If stab cultures in gelatin are made from one of these 

 colonies, small round colonies, with lines radiating toward the 

 periphery, appear along the stab; these lines become divided and 

 finally form a hairy or cloudy mass. After six to ten days the gelatin 

 culture has a very characteristic appearance which has been likened 

 to that of a test-tube brush. The surface of the gelatin remains free; 

 no growth occurs on it. On a streak culture on gelatin slants the 

 colonies are more like those on gelatin plates. Sometimes, however, 

 the colonies form round whitish or yellowish-brown globular masses, 

 without the appearance of brush-like extensions. On agar and blood 

 serum the bacillus grows very scantily, but better when the tubes 

 are kept in an atmosphere from which the oxygen has been removed 

 by Buchner's pyrogallic acid method. The organism grows in 

 bouillon, and first slightly clouds the medium; later a scanty grayish- 

 white deposit is formed. It does not grow on potatoes kept aero- 

 bically, but it has occasionally been raised on potatoes kept in an 

 oxygen-free atmosphere. Smears from artificial cultures show the 

 organism singly, in pairs, and in short, wavy, or angular chains; 

 involution forms are frequently formed. 



