46 SHELLFISH CONTAMINATION FROM SEWAGE-POLLUTED WATERS. 
exposed to conditions favorable to fecal contamination. Occasion- 
ally data in regard to the probable sources of pollution of a given 
food product can not be obtained, but as the work progresses and 
opportunity is afforded to study these problems from various points 
of view, it becomes more apparent that the colon test is invaluable as 
an index of pollution 
Aside from being a mere indication of existing danger from sewage 
pollution, the colon bacillus is fast assuming the réle of a pathogenic 
organism. Various intestinal derangements and other visceral dis- 
orders are now ascribed to B. coli infection. In a recent article 
Thompson * presents evidence substantiating the relationship of 
B. coli to certain pathological processes of the abdomen, such as 
appendicitis. Under normal conditions the colon bacillus appears 
to exist as a harmless organism in the intestinal tract, but in the pres- 
ence of irritating substances or under abnormal putrefactive and 
fermentative conditions this bacillus seems to become an active factor 
in the causation of disease. The author has recovered a virulent 
strain of the colon bacillus and reproduced fatal infections in dogs, 
cats, guinea pigs, and pigeons. These results usually resulted from 
inoculating the animals with small quantities of a 24-hour bouillon 
culture, although in some cases infection was brought about by 
feeding material infected with the organism. The colon bacillus 
probably plays a further réle as a pathogenic organism by producing 
toxins in albuminous food materials of a highly perishable nature. 
In such a product as shucked oysters, if there is a high bacterial count 
with thousands of B. colt present per cubic centimeter of the oyster 
liquor, it is highly probable that toxic substances have already been 
elaborated. With the consumption of such material gastroenteritis 
to some degree must invariably follow. Undoubtedly many obscure 
cases of ptomain poisoning and other intestinal disorders of lesser 
magnitude could be ascribed to eating tainted food, especially if the 
substances are rich in albumin and bacterial activity has appreciably 
developed. 
In summarizing her work on the chemistry of the colon bacillus, 
Leach * gives the following analysis, showing the presence of toxins 
together with other complex substances in the cell of the colon 
bacillus: 
Elementary analyses show that age, conditions of growth, and especially the com- 
position of the nutrient medium cause bacteria of the same strain to differ widely in 
elementary composition. Proteid, nucleo-proteid, nucleic acid, protamin, fat, wax, 
lecithin, glycogen, and other carbohydrates have all been reported as obtained from 
the bacterial cell in varying degrees of purity. Cellulose seems to be present in cer- 
tain species, but by no means in all. Besides the preparations mentioned above, 
crystalline compounds have been prepared and purified, proving the presence in the 
cell of xanthin bases, pentose, fatty acids, and perhaps thymin and uracil, toxins, 
enzyms, and agglutinins have been split off from the cell, but more progress has been 
made in determining their physiological action than their chemical nature. 
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