Coliform Intermediates in Human Feces

Abstract

Although foundation for the recognition of coliform intermediates was laid by Brown (1921), he did not utilize his findings for their demonstration. Brown was interested in mediums containing citrated blood and attempted to determine the effect citrate might have on the growth of organisms likely to be encountered in blood culture work. Koser (1923, 1924a, b, c, d, 1926) applied to coliform bacteria (Breed and Norton, 1937) tests involving utilization of organic acids and their salts. He found that Bacterium coli from feces could not utilize citrate as a sole carbon source in contrast to Bacterium aerogenes. Koser found, particularly in soil and water, organisms classed as coli by the criteria then used but which utilized citrate-carbon and, in this respect, resembled B. aerogenes. In 1924 Koser applied the term "intermediate" to these forms. Recognition of such intermediate forms should make possible a better theoretical understanding of the entire coliform group, than which few in bacteriology are more complex or confused. Any fundamental advance, such as the intermediate concept, should enable sanitary science to define more accurately such terms as "pollution" and "potability" and to answer numerous practical questions posed in this field in recent years. Parr (1936a, b, 1937) defined intermediates as coliform organisms "which have one or more coli characters and one or more of those attributed to aerogenes, and some 'intermediates,' including the typical fecal form, produce hydrogen sulphide." This definition permits the inclusion as intermediates of organisms 1

Type Differentiation of Coliform Organisms With Membrane Filter Technique

“…This evidence supports the concept that ERC Endo medium and BGF medium are qualitatively and quantitatively equivalent in producing sheen colonies for a wide variety of IMViC types. These results essentially agree with those reported by other investigators (3,4,6,7) in the relative frequencies of the various IMViC types and in the number of IMViC categories represented (Table 5). In practically all instances, discrepancies in the frequency percentages are attributable to differences in the bacterial flora of the culture sources.…”

BACTERIOLOGICAL FLORA IN FROZEN AND CHILLED ORANGE JUICEa

“…Some of the culture characteristics of organisms isolated from production and experimental samples of chilled antl frozen orange juice by a direct plating method are presented in Tables 1 and 2. It can be seen that by using Yarr 's scheme, (13,14) and grouping the 150 isolates according to their IMVIC pattern, they fall into two major groups as follows:…”

Membrane Filter Procedure for Enumerating the Component Genera of the Coliform Group in Seawater

“…More important, about one-half of the Klebsiella isolates obtained from certain industrial efflu-ents free of fecal contamination would fit the definition of fecal coliforms (3). Another approach toward increasing the specificity of coliforms as indicators has been to type them according to their IMViC reactions (indole, methyl red, Voges-Proskauer, and citrate tests) (20). However, IMViC typing presents some problems.…”