CHAPTER XLIII 



DISEASES CAUSED BY SPIEOCH^ETES (TEEPONEMATA), CLASSI- 

 FICATION, SYPHILIS AND TEEPONEMA PALLIDUM, EELAPS1NG 

 FEVEES, VINCENT'S ANGINA, YAWS, AND THE SPIROCHAETE 

 PEETENUE, SPIEOCHvETE GALLINAEUM, EAT BITE FEVEE, NON- 

 PATHOGENIC SPIEOCHJETES OF THE HUMAN BODY. 



THE microorganisms known as spirochsetes are slender, undu- 

 lating, corkscrew-like threads which show definite variations both 

 structurally and culturally from the bacteria as a class. Most im- 

 portant among them are the spirochaete of relasping fever, Spirochaete 

 pallida of syphilis, the spirillum of Vincent, Spirochaete refringens, 

 Spirillum gallinarum, a microorganism which causes disease in 

 chickens, Spirochaete anserina, which causes a similar condition in 

 geese, and several species which have been found as parasites, both 

 in animals and in man, without having definite etiological connection 

 with disease. 



CLASSIFICATION OF SPIRAL ORGANISMS 



Classification of the spiral organisms in general is still unsatis- 

 factory because the difficulties of staining and cultivation have made 

 it impossible to apply to these organisms the same exact criteria 

 which can be applied to most species of bacteria. We may say, in 

 general, that the word spirillum should be retained for true bacteria 

 of spiral form in which the cell body is rigid and motility is brought 

 about entirely by flagella. Such, for instance, are the spirillum of 

 Asiatic cholera, the spirillum Metchnokovi, the spirillum Deneke 

 and others. 



The true spirochaete are probably not true bacteria, and we have 

 no exact criteria upon which we can base their classification with 

 the protozoa. However, the striking parasitism of most of them, 

 and certain features of their immunological relations would suggest 

 that they either belong to, or are very close to protozoa. Schaudinn, 

 the discoverer of the syphilis organism, classified the treponema 

 pallidum with the protozoa on the basis of morphological study. 

 He believed that stained preparations often showed an undulating 



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