. 74 Elements of Water Bacteriology. 



Schepilewski (Schepilewski, 1903) and Altschuler 

 (Altschuler, 1903) have also used agglutination as a means' 

 of precipitating the bacteria after enrichment cultivation 

 in broth. The former incubated the culture at 37 degrees 

 for 24 hours, then added a serum of high potency, allowed 

 the mixture to stand for two to three hours and then 

 centrifuged. The supernatant liquid was removed, and 

 the mass of agglutinated cells broken up by shaking 

 with glass beads and salt solution. Upon plating upon 

 litmus lactose agar the organisms could be detected. 

 In this way positive isolation was made from water 

 containing i loopful of a broth culture in 50 liters of 

 water. Altschuler's method of enrichment was essen- 

 tially like that of Schepilewski. From the surface of the 

 culture developed at 37 degrees, 10 c.c. were removed 

 to a tapering tube provided with a rubber tube at the 

 bottom. Serum was added in the proportion of one part 

 in 50, the culture agitated to release entangled non- 

 agglutinated bacilli and the sediment run into a tube 

 containing i per cent peptone and \ per cent salt. The 

 agglutinated mass was broken up by shaking with sand, 

 and the culture incubated at 37 degrees for 24 hours, and 

 then plated on Drigalski-Conradi plates. The organism 

 was isolated from dilute suspensions in water (150 in 

 I liter) and also from the feces of a typhoid patient with 

 which other methods gave negative results. 



A number of methods for concentrating typhoid bacilli 

 in water by chemical precipitation have been tested expefi^ 



