460 A MANUAL OF BACTERIOLOGY 



Mycosis tonsillaris (Mycosis pharyngis lepto- 

 thricia) 



A chronic disease attacking young adults, resistant to treatment, 

 and characterised by the presence of small, white, tough, adherent 

 excrescences on the mucous membrane of the pharynx. Micro- 

 scopically, the patches consist of collections of epithelial cells and 

 debris, infiltrated with leptothrix filaments and bacteria. The 

 disease, however, seems to be a keratosis, infection with the 

 organisms being secondary. 



But occasionally a true " mycosis " apparently occurs, readily 

 amenable to treatment, and due to a leptothrix. 1 



Leptothrix buccalis 



Four somewhat similar thread forms occur in the mouth, viz. 

 Leptothrix racemosa, L. buccalis maxima, L. innominata, and 

 Bacillus maximus buccalis. The first is very common, forms large 

 threads, shows a peculiar beaded appearance on staining which has 

 been regarded as sporulation, and may be a fungus form. L. buccalis 

 maxima and L. innominata differ from each other in that the former 

 gives a blue granulose reaction when treated with iodine and dilute 

 sulphuric acid, while the latter does not. All these three organisms 

 are very similar, and the filaments are either unsegmented, or the 

 segments are of considerable length. The B. maximus buccalis is 

 very like the L. buccalis maxima, but does not give the granulose 

 reaction, and its segments are shorter. It is motile, flagellated, and 

 sporing, and stains by Gram's method. 



Some confusion exists respecting the thread forms of the mouth. 2 



Cladothrix dichotoma 



An organism not unfrequently met with in natural waters. It 

 forms long threads, straight, or sometimes slightly undulating, or 

 even spiral and apparently branched, though the branching is not 

 dichotomous. It can be cultivated on the ordinary laboratory 

 media at room temperature, forming on agar a brownish, wrinkled, 

 tough, membranous layer, very adherent, and staining the medium 

 beneath it a pale brown, not unlike the Actinomyces in these respects. 

 It is non-pathogenic. 



1 See Glasgow Medical Journal, No. 2, 1896, p. 81 et seg. (Brown 

 Kelly). 2 See Goadby, Mycology of the Mouth. 



