108 DEPARTMENT OF THE NAVAL SERVICE 



From this discussion it will be obvious tliat whatever the source of the colon 

 bacteria, there is reason for investigation when they are present in the finished pro- 

 duct — the canned sardines of commerce. In a report of the subsequent work which 

 has been undertaken for the Biological Board refinite results are to be given from the 

 later experiments which bear directly on some of the points referred to above. 



The relationship of bacteria of the colon group to food poisoning is worthy of 

 attention. In some cases of poisoning where these organisms liave been recovered from 

 the patient in large numbers, there has been no evidence to show that they have been 

 the direct or indirect cause of the illness. In other instances, the workers investigating 

 the cases have stated as their conclusion that the illness has been the direct result of 

 infection of the food by bacteria of the colon group. 



On the whole, it may at least be said that any consumer in using sardines from 

 swelled or blown cans as food, is taking a quite unnecessary and unwarrantable risk. 



Summary. 



(1) Forty cans of sardines, " normals '" and " swells " have been examined. 



(2) Eiglit varieties of gas-producing bacteria have been recovered from the 

 material in the swelled cans. 



(3) Certain of the bacteria on injection into normal cans have produced typical 

 " swells." 



(4) From the experimental cans the bacteria have again been recovered, and have 

 been proved identical with the organisms taken from the original cans. 



(5) The rules of proof have thus been applied, and the investigation has shown 

 that, — 



(6) "SiveUs" or "hlovn cans" arp causod hy gas-producing hacteria. 



(7) Ko gas-producing bacteria have been found in normal cans of sardines. 



Note. 



(a) The technical scientific report of the investigation with which this paper 

 deals, has been issued. See "The Bacteriology of Swelled Canned Sardines," by 

 Wilfrid Sadler, published by the Biological Board of Canada, Ottawa. 



(b) The investigation has now reached the stage where it will be possible to fol-, 

 low this paper almost immediately with further papers on the later work. These 

 further papers will deal with : — 



(1) Experiments conducted under commercial conditions. 



(2) The sources of the bacteria responsible for the " swells". 



(3) Practical suggestions, based on the results of the investigation, as to how 

 losses and wastage due to " swells "' may be eliminated. 



