370 GLANDERS ANTHRAX PYOCYANEUS 



from the tunica vaginalis to the epididymis. The peritoneum is 

 inflamed, and if the organism is not very virulent there is joint 

 involvement and gradual emaciation and death. This is known as the 

 Straus reaction. 



Human. The essential lesion in man is similar to that in the horse 

 a granulomatous nodule made up chiefly of epithelioid cells and 

 many lymphoid cells. The bacilli occur in these nodules in large 

 numbers as a rule. The nodules occur chiefly in the nasal mucosa, 

 or in cutaneous infections under the skin; they break down readily, 

 causing ulceration or abscess formation. A crop of papules, which 

 soon break down, appears on the face, around joints, and frequently 

 upon the arms. The disease terminates fatally in about 65 to 70 per 

 cent, of all cases. 



Immunity and Immunization. Recovery from an attack of glanders 

 does not appear to confer immunity to subsequent infection, and 

 attempts to induce immunity in susceptible animals by vaccines, by 

 the use of mallein, or by sera have been unsuccessful. Specific agglu- 

 tinins and precipitins are present in the blood serum of infected animals 

 and a diagnosis can be made by the method of complement fixation. 

 The latter procedure, important in horses and other domestic animals, 

 has not been tried very extensively in man, partly because of the 

 comparative rarity of cases. 



Bacteriological Diagnosis. 1. Microscopical Examination. Material 

 from the purulent discharges of the nose or scrapings from cutaneous 

 nodules are stained by Gram's method and by Loffler's alkaline 

 methylene blue. The organism is Gram-negative, and frequently 

 exhibits a beaded appearance not unlike the diphtheria bacillus. A 

 diagnosis based upon purely morphological characters is not reliable. 



2. Cultural. Scrapings from unopened granulomata or from the 

 organs postmortem should be inoculated upon potato having an 

 alkaline reaction. The characteristic appearance of the growth upon 

 this medium is suggestive", but not conclusive. Bacillus pyocyaneus 

 grows very similarly. Pus must be plated upon glycerin agar or blood 

 serum, because the discharges from ulcers and abscesses are almost 

 invariably contaminated with other organisms. Pure cultures are 

 examined microscopically and injected into male guinea-pigs intra- 

 peritoneally. 



3. Animal Injection. The intraperitoneal injection of suspected 

 material into the peritoneal cavity of male guinea-pigs leads, in the 

 absence of organisms capable of causing a violent peritonitis, to the 



