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VI. THE SPORE FORMING LACTOSE FERMENTERS AND 

 THEIR SIGNIFICANCE IN WATER ANALYSIS. 



Spore forming lactose fermenters are not infrequently encountered 

 in water. They are for the most part anaerobes resembling the Cl. welchii 

 (B. aerogenes capsulatus of Welch) or the Cl. enteritidis sporogenes group 

 of Kline, but recently spore formers capable of growing on aerobic plates 

 have been reported and isolated by Meyers, Ewing and Ellms and Hinman 

 and Levine. They interfere seriously with the presumptive test for the 

 colon group. 



Sanitary Significance. Very little is known as to the source, dis- 

 tribution, or pathogenicity of the aerobic sporing types. Ellms reports 

 their presence in feces while Ewing emphasizes that they were present in 

 water only after heavy rains, so that they may represent soil forms. No 

 reliable conclusion can be drawn at present as to their sanitary significance. 



The anaerobes may be frequently encountered, often in large numbers, 

 in the intestinal tract of man. Kline and Houston report 30 to 2,200 

 CL (enteritidis) sporogenes per c. c. in sewage, whereas in waters of good 

 quality such forms are often absent even from large volumes. These obser- 

 vations have sometimes led to the contention that the presence of Cl. (enter- 

 itidis) sporogenes or closely allied bacteria in water is indicative of fecal 

 pollution. The employment of these organisms as indices of dangerous 

 pollution appears to the author unwarranted, undesirable and impractical 

 for, 



1. They are not characteristic of the human intestine. 



2. There is a very little correlation between the incidence of Sporogenes 

 and Welchii types in water and the sanitary survey. 



3. They are extremely resistant. 



The anaerobic lactose fermenters are verv widely distributed in nature. 

 They are encountered in large numbers in manures from various animals, in 

 decomposing organic materials, and in the soil. They cannot be considered 

 distinctive or characteristic of the human intestinal tract. 



In surface waters, the number of spores is remarkably constant, quite 

 independent of the degree of sewage pollution as indicated by sanitary in- 

 spection. 



Thus Gumming reports "Unlike B. coli which varies many thousand 

 percent, from several hundred per c. c. to less than 1 in 10 c. c., according 

 to the intensity of pollution, these spores were found often in the best 

 river water in 10 c. c. and seldom showed an average much above 4 or 

 5 per c. c " 



"Their number furnishes no clue to the degree of pollution and puri- 

 fication as does the number of B. coli " 



"The generally uniform distribution of organisms of this group in 

 surface water, even in those not highly contaminated with sewage, and with 

 no considerable increase in polluted waters, indicates that this group is 

 not, as has sometimes been supposed, an organism characteristic of the 

 intestine." 



