THE COLON-TYPHOID GROUP 97 



They are one and all certified to be harmless to human 

 beings, and in some cases this is based on actual ex- 

 periment. As Bainb ridge says, the entire innocence of 

 the bacterial viruses for man is a statement which needs 

 justifying. 



Collingridge attributed an outbreak of illness lasting 

 forty-eight hours and characterised by headache, giddi- 

 ness, and cramp to a virus used for killing mice in a 

 London business establishment. Nine girls at an Irish 

 convent school died, and McWeeney attributed the out- 

 break to B. enteritidis in beef, which, he said, was possibly 

 infected by sick mice in the larder. 



Savage and Read found true (Gartner) B. enteritidis 

 in the spleen and liver of apparently healthy rats and 

 regarded its presence as the result of an old infection 

 from which the rats had recovered. Savage thinks that 

 there is a strong probability that rats surviving an epi- 

 zootic of this nature will act as carrier cases for some 

 time. 



Morgan's No. 1 Bacillus. While this, or a very similar 

 organism, is to be found in the normal stools of children 

 occasionally, it is much more frequent in the motions of 

 summer diarrhoea of children, and is accepted as being 

 frequently the cause of this condition. It produces acid 

 and a little gas in dextrose, but does not ferment lactose, 

 saccharose, nor mannite. It does not liquefy gelatin nor 

 give the Voges-Proskauer reaction, but it produces indole 

 and slowly turns milk alkaline with no primary acidity. 

 It has been found on flies in houses with cases of summer 

 diarrhoea. 



Diseases of Calves. Gartner group bacilli are responsible 

 for or present in some cases of septicaemia, dysentery, 

 pneumonia, and other septic diseases of calves. Jensen's 

 paracolon bacillus of calf dysentery belongs to the group. 



The Typhoid Bacillus. 



Morphology. B. typlwsus (the Eberth-Gaffky bacillus) 

 is 2 /UL to 4 //, long by 0-5 JLI thick, with rounded ends, but 

 shorter, longer, and, occasionally, filamentous forms are 

 seen in cultures. No spores are formed, but granules 

 and vacuoles may be seen. Involution forms 10 /LI to 

 30 fj, long are obtained on repeated subculture, and are 

 somewhat characteristic. The organism is aerobic and 



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