Relationships of Coliform Organisms

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Abstract
Of 5200 coliform colonies isolated from milk, cow hides, dust of cow barns, and human and bovine feces 4608 gave acid and gas in lactose at 37[degree]C, about 40% of the remainder gave acid and gas at room temp. but not at 37[degree]C, and the rest gave only acid at both temps. 3247 strains, confirmed at 37oC, were classified on the basis of their reactions in indol, methyl-red, Voges-Proskauer, citrate. and cellobiose mediums. These were divided into 3 groups "A," indol [long dash], V-P+ ; "B," indol [long dash], V-P[long dash]; and "C," indol+ , V-P [long dash]. Each group was subdivided into 6 types by means of citrate and cellobiose. A 4th group (indol+ , V-P+) consisted of a single type. "Irregular" strains which conformed to none of the types at 37[degree]C could be classified by testing at room temp. Several strains, changing in reaction in citrate or cellobiose, "shifted" in type. "Shifts" of this sort were confined within the groups. Only 2 strains, which acquired the ability to produce indol. shifted in group. 200 cultures isolated from decayed parts of fruits and vegetables were related to the coliform group. Statistical analysis of the data indicated that the grouping based on indol and Voges-Proskauer reactions was more suitable than one based on citrate and Voges-Proskauer.