454 THE SPIROCHETES 



With the discovery of the cause of infectious jaundice in 1915 by Inada and Ido/ 

 still another morphologically distinct spirochete was added to the family of Spiro- 

 chaetaceae. That this organism (Fig. 123) possesses certain peculiarities was recog- 

 nized first by its discoverers, who pointed out the hook formation of one or both ex- 

 tremities and the beaded appearance by darkfield illumination which later proved 

 to be due to the closeness of the spiral windings. The appearance and movements 

 of the organism are so characteristic that the writer^ in 191 7 introduced the genus 

 Leptospira for it. It developed later, however, that Stimson^ had already described 

 this type of spirochete in 1907 (Fig. 119), having discovered it in the kidney from a 

 patient dying of yellow fever and designated it Spirochaeta{?) interrogans because of 

 its hooked extremities. Hence the type species of the genus Leptospira automati- 

 cally shifts back to Stimson's interrogans, which antedated Inada and Ido's ictero- 

 haemorrhagiae, and the name Leptospira icteroides, which was given by the writer 

 to the leptospira isolated in 1918 from yellow-fever patients (Figs. 120-21), becomes 

 a synonym of Leptospira interrogans. Other spirochetes belonging to this same group 

 have been discovered, as will be recorded in detail farther on. 



The cultural requirements of various groups of spirochetes are quite different. 

 Strict anaerobiosis and the presence of serum and fresh tissue are essential for the 

 pallidum and refringens types. The relapsing-fever spirochetes and the leptospiras 

 are obligatory aerobes.^ According to Zuelzer ,5 Spirochaeta plicatilis can be grown in 

 association with bacteria in an air-tight container in water-containing hydrogen 

 sulphide. The cristispiras and saprospiras have never been cultivated. 



From the standpoint of pathogenesis, the pallidum is typical of the tissue parasites, 

 which cause chronic manifestations similar to those of a protozoan infection. The re- 

 lapsing fever organisms are principally blood parasites, while Leptospira interrogans 

 and Leptospira icterohaemorrhagiac invade both the blood and the tissues. None of 

 the organisms of genera 1,3, and 4 described below is so far known to be pathogenic 

 for man. The classification which the writer suggested in 191 8 has been modified 

 only as regards the recurrcntis group, which has been retained with the treponemas 

 for the reasons already stated. 



Genus i: Spirochaeta (Ehrenberg, 1833)* Type: S. plicatilis (Ehrenberg, 1833) 

 Genus 2: Treponema (Schaudinn, 1905)! Type: T. pallidum (Schaudinn and Hoff- 

 mann, 1905)11 

 Genus 3: Cristispira (Gross, i9ii)t Type: C. halbianii (Certes, i882)1[ 



Genus 4: Saprospira (Gross, 1911)$ Type: .9. grandis (Gross, 1910)** 



Genus 5: Leptospira (Noguchi, i9i7)§ Type: L. interrogans (Stimson, i907)tt 



*Ahhandl. d. Akad. d. Wissensch. zu Berlin, 1833, p. 313. 1834; Die Infiisionslierclien. 1838. 



^Deutsche med. Wchnschr., p. 1728. 1905. 



tMitt. a. d. zool. Station zu Neapel, p. 188. 1911. ^Bull. Soc. zoo!, de France, 7, 347. 1SS2. 



§7. E;r/)er. M«/., 25, 755. 1917. **0/>. ci'/., 20, 41. 1910. 



WArb. a. d. kaiserl. Gesundheitsamte, 22, S21- 1905. ^]U -S. Pub Health Rep. 1907. 



' Inada, R., and Ido, K.: Tokyo Iji-shiiislii. (Feb.) 1915. 



- Noguchi, II.: J. Kxpcr. M'd., 25, 755. igiy. 



3 Stimson, A. M.: U.S. Pub. Ileallh Rep., 22, Part I, 541. 1907. 



1 Some authors apparently have the misconception that these organisms can grow witiiout 

 ox> gen because they grow under a hij'er of paraflin oil, whereas the oil la\cr docs not interfere with 

 the penetration of oxygen and is used only to delay the c\aporalion of the medium. 



^ Zu U-r. i\I.: .1)7//. f. Prolisleiik., 24, i. iqi i. 



