438 THE SALMONELLA GROUP 



fermentation of dulcite is delayed and then a loopful plated out on Conradi- 

 Drigalski's or MacConkey's medium. 



After incubating the plates for 24 hours a number of the colourless colonies 

 are picked off and tested as regards their morphology, staining reactions, 

 cultural characteristics (gelatin slopes and litmus milk) and biological pro- 

 perties (glucose, lactose). 



If bacilli be isolated having up to this point all the characteristics of the 

 paratyphoid B bacillus it is absolutely necessary, in order to definitely identify 

 the organism, to test its reaction with a known serum both before and after 

 absorption. If a specific serum be not available it will be necessary to 

 inoculate a rabbit with minute doses of a living culture intra-venously 

 (vide supra) and to test the action of this serum on a known paratyphoid B 

 and a known aertrycke bacillus both before and after absorption. 



2. BACILLUS ENTERITIDIS AERTRYCKE. 



Synonyms : Bacillus of hog cholera : Bacillus suipestifer : B. cholerse suis. 



The aertrycke bacillus was isolated in 1898 from epidemics of food- 

 poisoning by Durham in England and De Nobele in Belgium and has 

 become known as the aertrycke bacillus from the name of the village in 

 which De Nobele's epidemic occurred. 



A bacillus known as the hog-cholera bacillus or bacillus suipestifer had 

 previously (in 1885) been isolated by Salmon and Theobald Smith from swine 

 suffering from a disease known as swine fever or hog cholera (Ger. Schweine- 

 pest). 



These two organisms are now admitted to be identical. 



There is at present no uniformity in the nomenclature of the bacillus, some writers 

 referring to it as the Bacillus suipestifer or bacillus of hog cholera, others as the 

 aertrycke bacillus. Bacillus suipestifer is undoubtedly its original name but the 

 term is misleading, as it implies a relationship which has been proved not to exist : 1 

 hence it has seemed better to adopt the title Bacillus enteritidis Aertrycke which 

 represents the usual role of the organism in human pathology. 



Occurrence in man. The aertrycke bacillus appears to be the organism most 

 frequently found in cases of " food poisoning " in man. " Food poisoning " is an 

 acute septicsemic condition accompanied by vomiting, diarrhoea and collapse, and 

 in severe cases terminating fatally. 



In healthy human subjects the organism does not appear to be present. 



Morgan isolated 2 strains of the bacillus from among 303 cases of summer diarrhoea, 

 and Williams, Bundle, and Murray isolated a bacillus Bacillus F now admitted 

 to be identical with the aertrycke bacillus (p. 437) from cases of the same disease 



In the lower animals the organism appears to have a wider distribution. Petrie 

 and O'Brien found it frequently in healthy guinea-pigs, and O'Brien has described 

 several guinea-pig carriers. 



In Germany "paratyphoid" bacilli probably the aertrycke bacillus (Bain- 

 bridge) have been isolated from the intestines of healthy pigs (Uhlenhuth 8 per 

 cent., Seiffert 3 '5 per cent.), from milk (Fischer), water (Conradi), and sausages 

 (Hiibener, Rommeler). Bainbridge and also Savage have failed to detect the 

 presence of this organism in the intestines or meat of healthy animals in England. 



x It should perhaps be pointed out here that in the opinion of Lourens and Glasser the 

 view that hog cholera is due to a " filter-passer " is not borne out by their own observa- 

 tions. According to these experimenters hog cholera is due to Salmon's bacillus which 

 can disintegrate into particles small enough under certain circumstances to pass through 

 porcelain niters ; that in all cases occurring during an epidemic the bacillus is found 

 with the filter-passer ; and it is certain that the bacillus alone can produce the disease. 

 This view is contested by Uhlenhuth. 



