DIPHTHERIA 85 



forty-eight hours, at the earliest, to seven to ten days. Cultures 

 should be made from this swollen testicle as other organisms than 

 glanders may bring it about. 



Only the B. pyocyaneus and cholera vibrios give a similar coloration of potato. 

 These organisms, however, are easily differentiated. The glanders bacillus is the 

 most dangerous of laboratory cultures and should be handled with extreme care. 



The best stains are carbol thionin and formol fuchsin. In sections stained with 

 carbol thionin the bacilli are apt to be decolorized by the subsequent passage of 

 the section through alcohol and xylol. This may be avoided by blotting carefully 

 after the thionin, then clearing with xylol or some oil and mounting. Nicolle's 

 tannin method is a good one. 



Mallein is prepared by sterilizing cultures that have grown in glycerine bouillon 

 for about a month by means of heat (100 C.). The dead culture is then filtered 

 through a Berkefeld filter and the filtrate constitutes mallein. It is chiefly used as 

 a means of diagnosing the disease in horses. The reaction consists in rise of tempera- 

 ture and local oedema. The dose is about i c.c. 



Agglutination and complement fixation tests are also used for diagnosing glanders. 



Bacillus diphtherias (Klebs discovered, 1883; LofHer cultivated, 

 1884). The diphtheria bacillus is found not only in the false mem- 

 brane which is so characteristic of the disease, but may be found in 

 abundance in the more or less abundant secretions of nose and pharynx. 

 In studying the epidemiology of diphtheria, especial attention must be 

 given to the examination of nasal discharges. 



Infection of the larynx and middle ear are not very rare. The 

 mucous membrane of the vagina or the conjunctiva may also be infected. 

 The B. diphtherias may be in pure culture lying entangled in the fibrin 

 meshes or contained within leukocytes in the membrane or be asso- 

 ciated with staphylococci, pneumococci, or especially streptococci. 

 These latter complicate unfavorably and cause the suppurative con- 

 ditions about the neck. In fatal cases the diphtheria bacillus may be 

 found in the lungs. Ordinarily, however, it remains entirely local and 

 does not get into the circulation or viscera. 



It produces soluble absorbable poisons which are designated toxin 

 in the case of the one responsible for the acute intoxication, paren- 

 chymatous degeneration and death; and toxone for the poison which 

 produces cedema at the site of inoculation and postdiphtheritic palsy. 

 The injection of the soluble poisons alone without the bacilli produces 

 the symptoms of the disease. 



The bacilli tend to appear as slightly curved rods, showing varying 

 irregularities in staining, as banding or beading, and in particular the 



