550 Relapsing Fever 



Spirochaeta obermeieri, measured 0.25 to 0.3 f* in breadth by 

 7 to 19 ^ in length. The number of coils varies from three 

 to six. The shorter forms are pointed, with a long flagel- 

 lum at one end and a short one at the other. 



Staining. The spirochaeta can be stained with ordinary 

 anilin dye solutions, by the Romanowsky and Giemsa 

 methods, and by the silver methods (see Treponema palli- 

 dum). It does not stain by Gram's method. 



Cultivation. The organism will not grow upon any 

 known culture-medium. Following the suggestion of 

 Levaditi, Novy and Knapp* cultivated Spirochaeta ober- 

 meieri in collodion sacs in the abdominal cavity of rats, 

 and succeeded in maintaining it alive in this way through 

 twenty consecutive passages during sixty-eight days. They 

 were able to do this in rat serum from which all corpuscles 

 had been removed by centrifugation, so that it is proved 

 that no intercellular developmental stage of the organism 

 takes place. Organisms thus cultivated are attenuated in 

 virulence. 



Norris, Pappenheimer, and Flournoyf believe that they 

 succeeded in securing multiplication of the spirochaeta by 

 placing several. drops of blood containing them in 3 to 5 c.c. of 

 citrated rat or human blood. A third generation always 

 failed. 



Mode of Infection. The means by which Spirochaeta 

 obermeieri is transmitted from individual to individual is not 

 definitely known. TictinJ seems to have been the first to 

 believe that the transmission of the disease was accomplished 

 through the intermediation of some blood-sucking insect. 

 He investigated lice, fleas, and bed-bugs, in the latter of 

 which he was able to find the organisms, and through blood 

 obtained from which he was able to transmit the disease to 

 an ape. He was not able to infect apes by permitting infected 

 bed-bugs to bite them. Breinl and Kinghorn and Todd 

 made a careful study of the subject, but, like Tictin and 

 their other predecessors, were unable to infect monkeys by 

 permitting infected bed-bugs to bite them. 



This leaves the transmission of the micro-organism un- 

 accounted for. When we come to consider Spirochaeta 



* "Jour. Amer. Med. Assoc.," Dec. 29, 1906, XLVII, p. 2152. 

 t "Journal of Infectious Diseases," 1906, in, 266. 

 J "Centralbl. f. Bakt. u. Parasitenk.," i Abt., xv, 1894, P- 840. 

 Ibid., Oct., 1906, xui, Heft 6, p. 537. 



