GENUS BACTERIUM 217 



covery of a particular plate method * for the isolation of the 

 abortion organism from contaminated material. MacNeal and 

 Kerr 7 verified Nowak 's findings and also isolated the organism 

 by inoculating the material subcutaneously into pregnant 

 guinea pigs, recovering the organism from the uterus after 

 abortion. The natural habitat of this organism outside of 

 the animal body is not known. 



Morphology. This organism appears as ovals or short 

 rods with rounded ends. They are observed in preparations 

 from the uterine exudate singly, in small clumps or in more 

 dense masses. In some preparations they appear as clumps of 

 agglutinated bacteria. They vary from 0.6 to 2.5 ju in length 

 and are about 0.8 /* in thickness. 



Staining. It stains readily but somewhat irregularly 

 with alkaline methylene blue and with dilute carbol fuchsin. 

 It is negative to Gram's stain. 



Cultivation. Bacterium abortionis was originally iso- 

 lated and cultivated artificially by Bang and Stribolt in agar- 

 gelatin-raw serum. This medium was inoculated while it was 



* For this purpose ordinary agar is melted and cooled to 50 C., 

 then mixed with about one-fourth its volume of naturally sterile 

 blood serum, and poured into sterile Petri dishes where it is allowed 

 to solidify. The piece of the placenta or other material from the 

 abortion is now streaked over several of these plates in succession, 

 according to the usual bacteriological technic for obtaining streak 

 dilution cultures. The plates are then placed at 37 C. for 24 hours 

 to allow contaminating aerobic bacteria to develop. Parts of the 

 plate surface free from colonies are now marked with a wax pencil, 

 as it is upon these areas that the growth of the abortion bacillus may 

 subsequently appear if it is present. The plates are next put into a 

 glass jar or desiccator together with a culture of the common hay 

 bacillus, B. subtilis. About 1 sq. cm. of culture surface of the latter 

 organism should be allowed for each 15 cc. air capacity of the jar. 

 The jar is now closed and placed at 37 C. for three days, at the 

 end of which time the transparent colonies of the abortion bacillus 

 will have developed, if it is present. The growth of the B. subtilis 

 culture serves to absorb the oxygen in the jar to just the partial 

 pressure required for the development of the abortion organism. 



T MacNeal and Kerr. Jour, of Inf. Diseases, Vol. VII (1910) p. 

 469. 



