TREPONEMA PERTENUE 



457 



E. H. Ross found cellular inclusions resembling Kurloff's bodies in mono- 

 nuclears in non-ulcerated Hunterian chancres, and examined them in detail 

 by placing the blood from such a chancre upon H. C. Ross's coefficient jelly. 



Similar bodies have been described by McDonagh, who has given an account 

 of a complicated life-cycle for T. pallidum (see second edition of this book, 

 p. 409). 



Pathogenicity. — 2\ pallidum is the cause of syphilis. 



Treponema pertenue Castellani, 1905. 



Synonyms. — -SpirochcBta fertenuis Castellani, June, 1905; Sfiro- 

 chceta pallidula Castellani, November, 1905. 



History. — -It was discovered by Castellani in 1905 in the scrapings 

 from yaws papules. 



Morphology.' — Treponema pertenue is an extremely delicate spiral- 

 shaped organism, varying in length from a few microns to 18 

 and 20 ^ and even more. It is very slender. Some individuals 

 are, however, thicker than others. It does not stain easily, but 

 good results may be obtained with Giemsa's method, and also with 

 Leishman's stain, provided the alcoholic solution is allowed to act 

 for five minutes, and the subsequent admixture with distilled w^ater 

 for from one half-hour to several hours. Using either of these 

 methods, the Treponemata stain purplish. Occasionally a few 

 more deeply stained granules may be seen in the body of the 

 organism. The extremities of the parasite are often pointed, but 

 forms may be met with presenting blunt extremities, or one ex- 

 tremity pointed and the other blunt. In some individuals one of 

 the extremities may present a large pear-shapv.d expansion or a 

 loop-like formation. The numiber of coils varies from six to tw^enty 

 or more, but they are, as a rule, numerous, uniform, and of small 

 dimensions. Occasionally a portion of the Treponema shows 

 numerous close uniform coils, v/hile the rest of its body show^s no 

 coils at all. Sometimes two Treponemata may be attached end 

 to end, or apparently twisted together. Castellani has not been 

 able to detect any undulating membrane, though its presence has 

 been asserted by other observers (Blanchard). Occasionally, in 

 preparations stained by Loffier's method of flagella staining, it has 

 seemed to several observers that some of the organisms present an 

 extremely delicate flagellum at one end. Prowazek has described 

 a resting form, oval or round, produced by a coiling up of the spiral. 

 Ranken, by means of the dark-ground illumination, has been able 

 to observe the extrusion from the parasite of small, highly-refractile 

 granules, which are apparently shot out by free lateral motion. 

 These granules immediately after extrusion remain stationary, then 

 begin to rotate and move about, though apparently not supplied 

 with flagella. 



Intracellular Stage. — Castellani in 1905 described some peculiar 

 bodies, free and intracellular, in leucoc^^tes, which possessed an oval 

 or roundish shape, and contained chromatin dots. At the time he 

 Was inclined to consider them to be stages in the development of 

 the parasite, but later he held that they Were cell inclusions of non- 



