460 INFECTION AND IMMUNITY. 



supposed to be due to ptomains which were found 

 in putrid meat, have occurred not infrequently. 

 It is now well established that most epidemics of 

 this character are caused by pathogenic bacteria 

 which are present in the meat, putrid decomposi- 

 tion of the latter being an unessential incident. 

 Ba . ci .l?J ls Gartner, in 1888, had the opportunity of studv- 



Eiiterititlis. . ' , , . -, 



ing an epidemic caused by the meat of a cow which 

 had been slaughtered in extremis. The symptoms 

 differed from those of botulism or paratyphoid, as 

 described below. He obtained from the muscle and 

 spleen of the cow, and from the spleen of a man 

 who had been fatally poisoned, an organism which 

 has since been known as Bacillus enteritidis (Gart- 

 ner). The same bacillus, or organisms which re- 

 semble it closely, have been obtained repeatedly 

 during similar epidemics, both from the suspected 

 meat and from the organs in fatal cases (intes- 

 tines, blood, spleen, etc.). Drigalski, from a com- 

 parative study of several strains obtained from dif- 

 ferent sources, concluded that all are members of a 

 closely related group of organisms, the group of 

 Bacillus enteritidis. His conclusions were based 

 on cultural properties and agglutination tests. 



The typical organism is a short rod, often ovoid 

 in shape, possesses from four to twelve long flag- 

 ella and has moderate motility. It ferments vari- 

 ous sugars and is not stained by Gram's method. 

 Variations among individual strains need not be 

 discussed here. 

 Patho- According to v. Ermengem, and also Drigalski. 



geiiicity. .. . .. n ,, , , .. . 



its pathogemcity depends on the elaboration or a 

 soluble but heat-resistant toxin. Bouillon cul- 

 tures twelve days old, in which the bacteria have 

 been killed by heat, also similar cultures from 



