The origin of some of the streptococci found in milk / by L.A. Rogers and Arnold O. Dahlberg, Dairy Division, Bureau of Animal Industry.

  • Rogers, L. A. (Lore Alford), 1875-1975
Date:
[1914?]
Catalogue details

Licence: In copyright

Credit: The origin of some of the streptococci found in milk / by L.A. Rogers and Arnold O. Dahlberg, Dairy Division, Bureau of Animal Industry. Source: Wellcome Collection.

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    THE ORIGIN OF SOME OF THE STREPTOCOCCI FOUND IN MIRK By L. A. Rogers and Arnoed O. Dahlberg, Dairy Division, Bureau of Animal Industry INTRODUCTION In the higher plants and animals we are accustomed to associating species with a more or less definite habitat. Certain animals are found only in certain localities. One species of trees may be found only on a particular type of soil. A still narrower limit of distribution is found in some of the parasitic fungi which grow only on closely related host plants. Zoologists or botanists find the types on which they base their descriptions in the natural habitat of the organism. This relation has not always existed in the published descriptions of bacteria. The association of a natural group with a particular habitat has been more or less incidental, except perhaps with the pathogenic bacteria, and even with some of these it is not impossible that the pathological con¬ ditions under which they are found may not be the true habitat of the species. The colon group, while it is frequently found in water and milk, has its natural habitat in the intestinal tract of warm-blooded animals. Winslow found that certain chromogenic cocci were associated with the skin of animals.1 Some of the English bacteriologists have pointed out that the streptococci from horse manure, for instance, have a set of physiological reactions which differentiates them from those from saliva or pathological conditions.2 It is only through a knowledge of the habitat and the study of sufficient cultures to establish a type that true bacterial species can be determined. If we were to write a description of the German people we would go to Germany, not to an American city where German immigrants live. Countless descriptions have been written of bacteria isolated from milk until we have come to consider certain types as peculiar to this medium. The bacteria found in milk, however, are a heterogeneous collection, and the true types of milk bacteria are to be sought in the sources from which milk is contaminated. Esten has suggested that the streptococci or lactic-acid bacteria of milk come originally from the mouth of the cow.3 The feces of the animal must, unfortunately, 1 Winslow, C. E. A., and Winslow, Anne R. Systematic relationships of the Coccaceee. ed. i, 300 p., illus. New York, 1908. 8 Andrewes, F. W. Report on the micro-organisms present in sewer air and in the air of drains. 36th Ann. Rpt. Local Govt. Bd. [Gt. Brit.], 1906-07, Suppl. Rpt. Med. Off., p. 183-204. 1908. 3 Esten, W. M. Bacterium lactis acidi and its sources. Conn. Storrs Agr. Expt. Sta. Bui. 59, 27 p., S fig. 1909. Journal of Agricultural Research, Dept, of Agriculture, Washington, D. C. Vol. I, No. 6 Mar. 25, 1914