512 



PATHOGENIC SPIRILLA. 



Stains with the usual aniline colors, but not hy Gram's method. 

 Biological Characters. An aerobic (facultative anaerobic ?), liquefy- 

 ing, motile spirillum. According 1 to Gamaleia, endogenous spores are formed 

 by this spirillum; but Pfeiffer does not confirm this observation, and it must 

 be considered extremely doubtful in view of the slight 

 resistance to heat killed in five minutes by a temperature 

 of 50 O. Grows in the usual culture media at the room 

 temperature. Upon gelatin plates small, white, puncti- 

 form colonies are developed at the end of twelve to six- 

 teen hours ; these rapidly increase in size and cause lique- 

 faction of the gelatin, which is, however, much more rapid 

 with some than with others. At the end of three days 

 large, saucer-like areas of liquefaction may be seen, resem- 

 bling- that produced by the Finkler-Prior spirillum and the 

 contents of which are turbid, while other colonies have 

 produced small, funnel-shaped cavities filled with trans- 

 parent, liquefied gelatin and resembling 1 colonies of the 

 cholera spirillum of the same age. Under the microscope 

 the larger liquefied areas are seen, to contain yellowish- 

 brown granular masses which are in active movement, and 

 the margins are surrounded by a border of radiating fila- 

 ments. In gelatin stick cultures the growth resembles that 

 of the cholera spirillum, but the development is more rap- 

 id. Upon agar, at 37 C., a yellowish layer resembling 

 that formed by the cholera spirillum is quickly developed. 

 Upon potato no growth occurs at the room temperature, 

 but at 37 C. a yellowish-brown or chocolate-colored layer 

 is formed, which closely resembles that produced by the 

 cholera spirillum under the same circumstances. In bouil- 

 lon, at 37 C., development is extremely rapid, and the 

 liquid becomes clouded and opaque, having a grayish-white 

 color, while a thin, wrinkled film forms upon the surface. 

 When muriatic or sulphuric acid is added to a culture in 

 peptonized bouillon a red color is produced similar to that 

 produced in cultures of the cholera spirillum, and even more pronounced. 

 In milk, at 35 C., rapid development occurs, and the milk is coagulated at 

 the end of a week ; the precipitated casein accumulates at the bottom of the 

 tube in irregular masses and is not redissolved. The milk acquires a strongly 

 acid reaction and the spirilla quickly perish. 



Pathogenesis. Pathogenic for chickens, pigeons, and guinea-pigs; rab- 

 bits and mice are refractory except for very large doses. Chickens suffering 

 from the infectious disease caused by this spirillum remain quiet and somno- 

 lent, with ruffled feathers ; they have diarrhoea ; the temperature is not ele- 

 vated above the normal, as is the case in chicken cholera. At the autopsy 

 the most constant appearance is hyperaemia of the entire alimentary canal. 

 A grayish-yellow liquid, more or less mixed with blood, is found in con- 

 siderable quantity in the small intestine ; the spleen is not enlarged and the 

 organs generally are normal in appearance. In adult chickens the spirillum 

 is not found in the blood, but in young ones its presence may be verified by 

 the culture method and by inoculation into pigeons, which die in from 

 twelve to twenty hours after being inoculated with two to four cubic cen- 

 timetres. The pathological appearances in pigeons correspond with those 

 found in chickens, but usually the spirillum is found in great numbers in 

 blood taken from the heart. A few drops of a pure culture inoculated sub- 

 cutaneously in pigeons or injected into the muscles cause their death in 

 eight to twelve hours. Gameleia claims that the virulence of cultures is 

 greatly increased by successive inoculations in pigeons, but Pfeiffer has 

 shown that very minute doses are fatal to pigeons and that no decided in- 

 crease of virulence occurs as a result of successive inoculations. According 

 to Gameloa, chickens may be infected by giving them food contaminated 



FIG 185. Spiril- 

 lum Metschnikovi ; 

 culture in nutrient 

 gelatin, end of forty- 

 eight hours Froma 

 photograph. (Fran- 

 kel and Pfeiffer.) 



