Pathogenic Bacteria 345 



SPIRALS 



TREPONEMA PALLIDUM 



Very fine, motile spirals, 0.25-0.30 by 6-14 microns. Stain 

 with clifRculty except with Giemsa's stain. Appear black with sil- 

 ver impregnation. Have a stiffly flexible motion. Possible cul- 

 tivation under anaerobic conditions in ascitic fluid with addition 

 of fresh rabbit kidney. Optimum temperature about 37° C. 

 The cause of syphilis in man; can be experimentally transmitted to 

 anthropoid apes and to rabbits. 



Like gonorrhea, the statistical figures for the case rates of 

 svphilis are unbelievably high. About 10% of the population in 

 the United States will yield a positive serological test for this 

 venereal disease during their lifetime, and between 1 and 2% of 

 children have congenital syphilis. 



The disease gets its name from Syphilus an infected hero in a 

 poem written by Fracastorius in 1530, and it has been recognized 

 in Europe since the latter part of the fifteenth century. History 

 suggests that syphilis was unknown in that part of the world until 

 Columbus's crew returned from their 1492 voyage to the new 

 world. 



Treponema pallidum was first recognized as the etiological 

 agent of syphilis by Schaudinn and Hoffmann in 1905, and the 

 generic and specific names when literallv translated mean "pale 

 thread." The organism is probably the least resistant of all 

 pathogenic bacteria; even short exposures to drying or to water will 

 kill the anaerobic spirals. 



Because of their poor staining qualities, Treponema are usually 

 examined under a dark-field microscope. As the words indicate, 

 the field of the microscope is dark, and the organisms appear as 

 unstained spirals. The characteristic movement of these bacteria 

 aids in recognizing them when fluids obtained from primary 

 syphilitic lesions are examined under darkfield illumination. 



Syphilis allowed to go untreated passes through three stages: 

 primarij, secondary, and tertiary. About four weeks after exposure, 

 a primary chancre appears, and another six weeks usually elapses 

 before secondary generalized symptoms put in their appearance. 



