TREPONEMA PALLIDUM 



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Treponema pallidum Schaudinn, 1905. 



Synonyms. — SpirochcBta pallida Schaudinn, 1905 ; Spironema pal- 

 lidum Vuillemin, 1905; Microspironema pallidum Stiles and Pfander, 

 1905; Trypanosoma luis Krzysztalowicz and Siedlecki, 1905. 



History. — -This treponema was discovered by Schaudinn in syphilis 

 in 1905 . The history of the finding of parasites in syphilis is interest- 

 ing, for as long ago as 1546 Frascastorius considered syphilis to be 

 a parasitic disease. In 1879 Klebs, and, later, Losdorfer and 

 Dohle in 1901, described parasites, and saw cell inclusions in the 

 disease, and in 1905 Siegel described an organism, Cytorydes luis, 

 in which there are flagellate bodies very closely resembling spiro- 

 chaetes. In 1905 Schaudinn, after investigating and reporting 



Fig. iT,g.— Treponema pallidum Schaudinn, 1905. 

 (From a microphotograph by J. J. Bell.) 



uQfavourably on Siegel's v/ork, found the Treponema pallidum, 

 which is accepted as the cause of the disease. Korte in 1906 described 

 free round bodies and cysts with threads in primary sores . E . H . Ross 

 has described an intracellular formation allied to his Lymphocytozoon 

 cobaycB, which develops into spirochaetes, and these researches have 

 in part been confirmed by Jennings. McDonagh also has described 

 a complicated life-cycle. 



Morphology.— It varies from 4 to 10 in length, average 7 ju,, 

 with a width up to 0-5 /j,. It is twisted into spirals, which vary 

 from six to twelve and more in number, the average being eight 

 to ten, and are to a certain extent preformed — i.e., not due to the 

 parasite's movements. It moves by rotation on a long axis by 

 gliding movements, forwards and backwards, and also by flexion 



