CHAPTER XIX 

 THE BACILLUS AND SPIRILLUM OF VINCENT 



Vincent's angina is an infection of the tonsils, mouth, pharynx or tongue 

 caused by two organisms in symbiosis the bacillus of Vincent, sometimes called 

 fusiform bacillus, and the spirillum of Vincent. 



The bacillus of Vincent, or bacilli indistinguishable from it, are occasion- 

 ally found in the mouth, not associated with the spirillum of Vincent, when 

 there is no disease. 



The spirillum of Vincent, or spirilla indistinguishable from it, are occasion- 

 ally found in the mouth, not associated with the bacillus of Vincent, when there 

 is no disease. 



Whenever both these organisms coexist in the mouth there are always ob- 

 vious signs of disease; the evidence indicating that it is caused by this spirillum 

 and bacillus and dependent upon their symbiotic relation. 



Reported findings indicate that these organisms seldom, if ever, attack any 

 part of the body other than the mouth and pharynx; that they remain localized 

 in the superficial lesion and that their injurious effect is largely, probably en- 

 tirely, limited thereto. 



Morphology. The bacillus of Vincent is fusiform, spindle-shaped, or, more 

 often, shaped like a banana; it may be perfectly straight, but frequently is 

 slightly curved. Typical organisms are thickest in the middle and taper to 

 pointed ends. The bacillus of Vincent is about 5 to 10 /* long and 0.6 /* wide in 

 the middle. It is not motile. 



The spirillum of Vincent varies from 5 to 20 /JL in length, is slender in propor- 

 tion and shows irregular curves irregular as to number and depth some- 

 times they are very distinct and again very faint. 



Staining. Both the bacillus and spirillum of Vincent stain with the usual 

 anilin stains, best with carbol fuchsin, and are Gram negative. 



Growth. The bacillus and spirillum of Vincent cannot be cultivated ex- 

 cept under anaerobic conditions at 37C. Growth appears on serum-agar and 

 Loeffler's blood serum in 2 or 3 days as pin-point, round, grayish colonies. 

 These colonies enlarge and may attain a diameter of 2 millimeters and may show 

 a yellow tint. 



Many tubes of serum agar and other media, regardless of how planted and 

 incubated, fail to show growth. Attempt to obtain cultures are frequently 

 frustrated by overgrowth of other organisms present in the material taken from 

 lesions. , 



Pathogenesis. 'The name angina was given to the infection caused by the 

 spirillum and bacillus of Vincent because the first cases studied presented the 

 superficial clinical appearance of diphtheria. Subsequent observations have 

 proved this a misnomer. 



91 



