370 PSEUDOTUBERCULOSIS AND ACID-FAST BACILLI 



ovoid forms are seen. The bacilli stain well with the ordinary watery 

 anilin stains; they are Gram positive; they often do not stain uniformly, 

 and then very much resemble the diphtheria bacillus, but are smaller 

 than the latter. The pseudotubercle bacillus of sheep is not motile 

 and does not form spores. Pure cultures can best be obtained from 

 material taken from the outer zone of the caseous material in closed 

 nodules. 



Cultural Properties. The bacillus grows poorly at room, better at 

 incubator, temperature. The first generation always grows poorly, 

 but the development is better in subsequent transplants. The 

 organism is a facultative aerobe. On agar small punctate, grayish- 

 white colonies appear after twenty-four hours, and after six to eight 

 days reach their maximum size of 0.5 to 3 mm.; the circumference 

 of the colonies is serrated, their surface dull and umbilicate, with con- 

 centric rings arranged around the depressed centre. In generations 

 subsequent to the first few the growth becomes abundant, the colonies 

 become confluent and form a thin, moist, opaque, slightly folded 

 film, which gives rise to threads when touched with the platinum 

 loop. In agar stick cultures small, roundish, grayish-white colonies 

 appear along the stick canal, and the surface becomes covered with a 

 growth similar to that on agar slants. The addition of glycerin to 

 the agar appears to be unfavorable. Bouillon, during the first six 

 hours of growth, becomes uniformly cloudy, then a granular sediment 

 is formed, and the supernatent fluid becomes clear again; on the 

 surface a dry, grayish-white, broken-up pellicle adhering fairly 

 firmly to the glass tube at the margin is formed. On coagulated 

 blood serum small, moist, shiny isolated colonies appear after thirty- 

 six to forty-eight hours, and after a few days form rhizoid processes 

 into the depths of the medium. The colonies on horse serum form a 

 white and on cattle serum an intensely yellow pigment. On the latter 

 a yellowish cloudy halo is formed around the colonies after some time. 

 On potatoes the bacillus forms a dust-like, dirty white film. It grows 

 in milk and does not change its reaction or physical conditions. It 

 does not ferment sugar nor does it form phenol or indol. The bacillus 

 of Preisz has its temperature optimum at 37 C., and growth ceases at 

 43 C. The bacillus is not very resistant to heat nor to the ordinary 

 disinfectants. 



Inoculation experiments with the bacillus of Preisz have been 

 made by Noergaard and Mohler, and typical lesions were produced in 

 sheep and guinea-pigs. Rabbits are more resistant; chickens and 

 pigeons are not susceptible to inoculations with the organism. 



An equine disease known as Lymphangitis ulcerosa equorum, or 

 "Lymphangite ulcereuse du Cheval" (French), has been described in 

 the chapter on Glanders under the head of Pseudoglanders. It is 

 now claimed that the bacillus discovered by Nocard in lesions of 

 horses suffering from this disease is identical with the Preisz bacillus 

 of pseudotuberculosis of sheep. 



