BACILLUS MALLEI AND MISCELLANEOUS BACILLI 355 



growth develops surrounded by a greenish stain on the potato. 

 Gelatin is not liquefied. The organism is killed by moist heat 

 at 55° C. in 10 minutes, and in- 2 to 5 minutes by 5 per cent car- 

 bolic acid or* I to 1000 mercuric chloride. It survives drying 

 for only a few weeks and dies out quickly "in water. Many 

 fnammals are susceptible to inoculation, including horses, guinea- 

 pigs, cats and dogs. Cattle are immune. Man is susceptible 

 and human glanders frequently ends in death. 



Mallein is analogous to tuberculin. A culture in glycerin 

 broth incubated for six weeks is steamed and filtered, and the 

 filtrate evaporated to one- tenth the original volume is the mallein. 

 This substance is toxic to animals suffering from glanders but 

 not poisonous to healthy animals. 



Glanders is a disease most common in horses, mules and asses. 

 It begins as an inflammation of the nasal mucosa with localized 

 nodular infiltrations which later ulcerate. The infection may 

 become generaHzed at once causing acute glanders and death in 

 one to six weeks, or it may progress very slowly and persist for 

 years as chronic glanders. The chronic type is common in horses. 

 After apparent recovery from the disease, nodules containing 

 living bacilh may be found in the lungs. Histologically the gland- 

 ers nodule consists of granulation tissue infiltrated with leukocytes 

 and tending to become purulent at the center. The bacilli leave 

 the body in the nasal secretion and in the discharge from ulcers. 

 Infection of equines takes place most frequently by ingestion of 

 food soiled by these discharges. In man the disease seems to 

 result from inoculation of small wounds in the skin. It often 

 runs an acute course terminating in death, but chronic glanders 

 with recovery also occurs in man. A few sad laboratory accidents 

 in which workers have become inoculated with glanders have 

 emphasized the necessity for caution in handling this organism. 



The bacteriological diagnosis depends upon (i) identification 

 of B. mallei, (2) reaction of the animal to mallein, (3) agglutina- 

 tion reaction, and (4) complement fixation. For the recognition 

 of the bacillus, some of the suspected material is suspended in 



