SPORE-FORMING ORGANISM FROM IOWA 335 



Subsurface colonies resembled those of B. coli, i.e., they were 

 circular or elliptical with an entire edge and showed a granular 

 internal structure. 



Litmus lactose agar. The surface colonies in 24 hours at 37C. 

 were faintly acid, otherwise resembling those described for plain 

 agar. 



The subsurface colonies were slightly acid resembling B. coli. 



Incubation for 48 hours increased the acid reaction. 



Endo agar. The medium employed was the product supplied by 

 the Digestive Ferments Company. On this medium B. coli was 

 observed to give a distinct red colony but only a slight metallic 

 sheen, if any. Inoculation was made only on the surface. 



The organism under consideration showed faint, but hardly dis- 

 cernible, growth in 24 hours at 37C. After 48 hours small flat, 

 round and amoeboid colonies about 1 mm. in diameter, pink to red, 

 with a more intensely colored edge and center, were developed. 

 We would certainly not consider it colon-like but these colonies 

 would have to be fished in compliance with the United States Treas- 

 ury Department Standard. 



Eosin methykne blue agar. Two media were employed; the simpli- 

 fied E. M. B. of Levine and the Difco product. The results were 

 similar. There was no growth in 24 hours and after 48 hours small 

 pinhead, discrete colonies about \ mm. in diameter with a distinct 

 metallic sheen were present. 



GROWTH IN LITMUS MILK 



All cultures were inoculated into two different batches of litmus 

 milk, made from skim milk powder, and incubated at 37C. 



The litmus was rapidly decolorized (24 hours) and the medium 

 acidified. After 4 days, coagulation could be induced by heating. 

 (Control tubes of B. coli also failed to coagulate unless heated). 

 There was no further apparent change until 24 to 30 days incubation 

 when evolution of gas followed by coagulation and extrusion of a 

 clear whey was noticed in 10 of the cultures. It was thought that 

 this reaction might be due to some contaminating organism, but 

 microscopic examination of all of the tubes of one set of milk cul- 

 tures showed only Gram negative long rods (and with a single ex- 

 ception, no spores) resembling the organism under consideration 



Four cultures were inoculated into milk, covered with melted 

 paraffine and heated at 80C. for 10 minutes (the so-called sporo- 



