ANNUAL REPORT, 1940 23 



pepper, paprika, and mustard. The bacteria found were common air- 

 borne varieties (B. siibtilis group) that are of no particular sanitary signif- 

 icance. Intestinal bacteria (coliform group) were not present. Bacteria 

 of intestinal types and of types capable of causing food poisoning (coli- 

 form bacteria, Salmonella strains, and staphylococci) inoculated into the 

 several spices did not survive for more than a few weeks. Some oils of 

 the spices were investigated and found to be sterile when they were pur- 

 chased. Some were found to have the power to inhibit bacterial growth. 

 More work will be done on this phase of the problem. 



Effects of Temperature on the Differential Reactions of Coliform Bac- 

 teria. (James E. Fuller and Sonnia Levine.) The evaluation of the san- 

 itary significance of certain members of the coliform group of bacteria in 

 rural water supplies (springs and wells) oflfers some puzzling problems. 

 The separation of definitely fecal strains from strains definitely of soil 

 origin is relatively simple; but there are numbers of strains which give 

 differential reactions between these two species, and the sanitary inter- 

 pretation of the so-called intermediate strains presents the problems. 

 Eijkman proposed incubating water-test cultures at 46° C, instead of at 

 the usual 2>7° C, on the basis that the fecal strains would give positive 

 tests for pollution (production of gas in lactose broth) at the higher tem- 

 perature while other strains would not. In the present study the differen- 

 tial tests (Imvic reactions) of a number of intermediate strains were tried 

 at several temperatures from 25° C. (room temperature) to 46° C. The 

 evidence indicated that by this method certain of the intermediates could 

 be placed in a group closely related to the fecal type (Escherichia coli). The 

 indol test worked especially well in this respect. 



Studies of Fecal Streptococci. (James E. Fuller and Robert S. Lubitz.) 

 This study is a continuation of work previously reported (Fuller and 

 Guiberson, Mass. Expt. Sta. Bui. 369, p. 20, 1940; France and Fuller, 

 Amer. Jour. Pub. Health, 30 (9) :1059-1062, 1940). In the bacteriological 

 testing of swimming pool water, it is desirable to differentiate between 

 fecal streptococci, and streptococci from the skin or from the nose and 

 throat. The former would indicate pollution of the water from intestinal 

 source, and the latter would indicate danger of skin or of respiratory 

 infection to users of a pool. 



In the study here reported an attempt was made to develop differential 

 methods by the use of media of high pH value, or of high sodium-chloride 

 content. Some information was obtained concerning the tolerance of fecal 

 streptococci and of coliform bacteria to both high pH and high sodium- 

 chloride concentrations in media. No successful differential procedure 

 was developed. 



Bacteriological Studies of Chocolate Syrups and Cocoa Powders Used 

 in Chocolate Milk. (James E. Fuller and R. W. Swanson.) This study 

 is being made in cooperation with W. S. Mueller of the Department of 

 Dairy Industry. The work has been undertaken only recently, so only 

 preliminary results can be given. The bacterial contents of the syrups 

 and powders vary a great deal. There is little indication to date that the 

 addition of either syrup or powder increases the bacterial counts of milk 

 except for the addition of the bacteria present in the syrups or powders 

 themselves. There is some indication that both chocolate and cocoa may 

 have the capacity to hinder the growth of certain bacteria. 



