i844 THE DYSENTERIES 



Under the term B. pseudo-dysentericus , Kruse described a non- 

 lactose fermenting bacillus which is the cause of many outbreaks of 

 asylum-dysentery in Germany. Later he used the term ' pseudo- 

 dysentery ' to denote every variety of dysentery caused by bacilli 

 other than those of the Shiga-Kruse type. 



Celli's B. coli dysentericus, according to the original description, 

 is motile, clots milk, and produces gas in some sugar media, and 

 therefore cannot be considered to belong to the dysentery group. 

 According, however, to more recent descriptions by De Blasi and 

 others, some strains of theB. coli dysentericus may not produce gas, 

 and may not clot milk, and closely resemble Flexner's bacillus. 



The true dysenteric bacilli may be differentiated from one another 

 by their varying fermentative actions upon carbohydrates, by 

 agglutination, Pfeiffcr's reaction, and Castellani's absorption - 

 method. A table showing the characters of the more important 

 dysentery germs as well as other intestinal bacteria will be found 

 in Chapter XXXVI., p. 944. We wish to emphasise, however, 

 the fact that the biological reactions of the bacilli are much more 

 reliable than the fermentative changes. 



The dysenteric bacilli are distributed mainly by the faeces of 

 persons suffering from the disease, but there are also ' dysentery 

 carriers ' in the true sense of the word, who are perhaps not merely 

 an important source of infection, but possibly the important factor 

 in the dissemination of dysentery. 



Strong and Musgrave have proved that infection takes place by 

 the mouth by feeding a man with pure cultures of the dysentery 

 bacillus, which quickly produced an attack of dysentery, charac- 

 terized by motions containing blood and mucus, from which the 

 typical bacilli were grown. 



The most prevalent method of infection is direct contact with a 

 patient or a carrier, or with articles or more especially food con- 

 taminated by them. The bacilH are conveyed from faecal matter 

 to the mouth by the contamination of food or drink, or the utensils 

 for preparing or serving the same. This method of infection is prob- 

 ably common in hospitals and asylums, cooks and all persons engaged 

 in handling food being possible disseminators. Another method of 

 dissemination would appear to be the dust, especially in places with 

 badly polluted soils. Flies, as has been experimentally demon- 

 strated by one of us, are capable of carrying the bacilli, and are 

 therefore probably a prolific source of infection in tropical countries. 

 Luckily the water-supply is very rarely infected. With regard to 

 lower animals, Kruse and Bowman have recorded spontaneous 

 bacillary dysentery in monkeys, due to bacilli of the Flexner 

 group, and Messerschmidt has found a bacillus of Type Y in the 

 faeces of apparently healthy rabbits, so tliat there may be a possi- 

 bility that lower animals are of importance in the spread of the 

 disease. 



It would, however, appear that the bacilli are capable of hving 

 in the ahmentary canal without causing the symptoms of the 



