48 Walter H. Burkholder 



demonstrated. The organism does not form spores, is Gram-negative, is 

 not acid-fast, and is a facultative anaerobe. 



Cultural characteristics 

 (All cultures incubated at 27° C. unless otherwise stated.) 



Beef-extract agar slants (pH 7.0). Growth is at first scanty to moderate, 

 filiform, translucent, white or slightly creamy, glistening, smooth except 

 at the edges, which often are wrinkled. The consistency is butyrous, 

 but in old cultures it may be brittle. There is no change in the medium. 



Beef-infusion agar slants (pH 7.0). The growth is similar to that on beef- 

 extract agar. A green fluorescent pigment has never been observed on 

 this medium. 



Beef -extract agar -plates (pH 6.9). Three-days-old colonies are approxi- 

 mately 2 millimeters in diameter, white but bluish by transmitted light, 

 smooth with edges entire. Later, the growth often shows a zonation 

 with edges slightly undulating (Plate VI, E). 



Beef-extract bouillon (pH 7.0). The broth becomes cloudy within twenty- 

 four hours. A delicate pellicle appears, which is readily broken up and 

 thrown to the bottom. A white granular sediment is formed. 



Gelatin stab (pH 6.6). (Temperature 21°C). In the original description 

 of this organism, it was stated that arborescent growth occurs on this 

 medium and that no liquefaction takes place. Further work with the 

 pathogene on other gelatins, however, showed that this is not al- 

 together correct. Tests with one of the original strains and with several 

 recently isolated strains proved the following to be nearer the truth: 



Growth appears along the stab in twenty-four hours; this sometimes 

 becomes somewhat arborescent. At the end of two weeks a slight 

 liquefaction begins, which proceeds very slowly. At the end of six weeks 

 the liquefied gelatin is often like a heavy oil. (The mistake in the 

 original description was probably due to the gelatin used.) 



Milk. No separation occurs. At the end of six weeks the milk appears 

 somewhat yellowish brown in color. 



Litmus milk. In five days the litmus begins to turn blue, and it remains 

 so throughout the experiment. At the end of six weeks the medium is a 

 rather muddy blue. 



Brom cresol purple milk. The milk begins to turn blue in five days, and 

 finally becomes a brilliant bluish purple. There is no further noticeable 

 change. 



Uschinsky's solution. There is a slight variation with the different strains. 

 A light clouding occurs in forty-eight to seventy-two hours, sometimes 

 with a delicate surface film. A greenish color appears in three to eight 

 days. Many shades of this color may be noticed, but at the end of six 

 weeks all cultures are a light grape-green. The growth is very cloudy 

 to turbid, with a heavy white pellicle and a heavy white sediment. 



