TREPONEMA REOVRRENTIS 



913 





In film 

 show 

 form. 



Fig. 215. — Treponema duttoni. 



of blood. In one place the spirochsetes 

 a tendency to agglutination in rosette 

 Giemsa. (xlOOO). [From specimen kindly 



supplied by the late Prof. J. G. Thomson.] 



Treponema lecurrentis 



Isolation.- — Observed by Obernieier 

 (1873) in the blood of patients with 

 European relapsing fever. 



Morphology.- — Actively motile spiral 

 organisms, varying considerably in 

 length but usually 10-20 /^ long. 

 Series of 5-10 fairly regular but loose 

 primary waves ; each spiral is 2-3 /j. 

 long and about 1 /i in amplitude 

 (Fig. 215). The width is usually given 

 as 0-2-0-3 II (VVenyon 1926, Hindle 

 1931), but this is probably an under- 

 estimate. Personal observations on 

 the organisms in blood have suggested 

 that 0-4 fi more nearly represents their 

 true diameter.^ This is supported by 

 the observations of Tilden (1937), who 

 found that the Umiting pore size for 

 filtration through Elford's gradocol 

 membranes was 0-57 [Ji. After trans- 

 verse fission the two new organisms 

 may remain comiected by a remnant 



of the periplast. Stains purphsh-red with Giemsa. Organisms are said to be shorter and 

 thinner in young culture, thicker and longer in old (Plotz 1917). 



Cultivation.. — First successful cultivation rejiorted by Noguchi (1912<;), who seeded a few 

 drops of citrated blood from the heart of an infected mouse or rat into a tube containing 

 15 ml. of unheated and unfiltered ascitic or hydi'ocele fluid and a small piece of sterile 

 rabbit's kidney. The blood was taken from the animal 48 to 72 hours after inoculation. 

 Multiphcation of the spuochsetes in the cultures was visible in 2 to 3 days, and reached its 

 maximum about the 7th to the 9th day. No change was noticeable in the medium, but 

 actively motile spirochsetes could be found in every field, arranged either singly, in chains, 

 or in masses. After about the 9th day a sudden decrease in their numbers occurred, and 

 spherical bodies and irregular protoplasmic masses appeared, indicating that the organisms 

 were undergoing degeneration. Subcultures were most successfully made on the 4th to 

 the 9th days. Other workers (Plotz 1917, KUgler and Robertson 1922, Sinton 1924, 

 Lapidari and Sparrow 1928, Yuan-Po 1933, Scheff 1935), using Noguchi's technique or more 

 often a modification of it, have claimed to cultivate relapsing fever spirochsetes in vitro, 

 but the results appear to have been very irregular (see Moroder 1929) ; no one appears 

 yet to have succeeded in estabUshing a culture that can be continued indefinitely in the 

 laboratory (see Soule 1942). On the other hand, growth can readily be obtained by 

 inoculation of the chorio-aUantoic membrane of the developing chick embryo (Chabaud 

 1939, Oag 1939, Soule 1942). The spirochaetes prodixce no change in the membrane 

 itself, but invade the blood of the embryo, where they may be demonstrated by the usual 

 methods. Some strains prove fatal to the embryo ; others do not. 



Resistfince and Metabolism. — Resistance is apparently similar to that of the more 

 susceptible vegetative bacteria. Said to remain viable in clotted blood for 6 days at 

 room temperature and for at least 100 days at 0° C. (Wynns and Beck 1935). Little is 

 known about metabohsm. According to Scheff (1935), glucose is broken down with pro- 

 duction of lactic acid and CO2, but no oxygen is used up. A moderate partial pressure 

 of oxygen, however, is required for growth ; there is no multiplication under strict anaerobic 

 conditions. 



^ Mr. J. E. Barnard, F.R.S., has kindly measured for us a strain of Trep. duttoni ; he finds it 

 to be 0-35 /i in diameter. 



