136 ESSENTIALS OF BACTERIOLOGY 



isms, by phenol. An epidemic has been traced to the eating 

 of oysters taken from contaminated water. 



Persistence in Water. Franckland kept bacilli alive in water, 

 sterilized by heat, seventy-five days; in filtered water at 19 C., 

 five days; at 6 C., twelve days. In ordinary water they are 

 likely to be destroyed in a few days by the overgrowth of other 

 bacteria. 



Products. Brieger found a ptomain in the cultures, which he 

 named typhotoxin, with the formula C 9 H 17 NO 2 . It has no 

 specific action. A toxalbumin insoluble in water has also been 

 isolated, but, as experiment animals are immune to the disease, 

 no definite actions have yet been determined. 



The cultures, when old, show an acid reaction. 



Vaccines. Dead cultures of tested virulence are injected 

 subcutaneously. This causes the blood to show agglutination 

 reaction, increased opsonic index, and a heightened immunity 

 to the disease. In several thousand inoculations observed 

 by Wright it is claimed the disease was much lessened in 

 severity and the tendency to infection much reduced. 



Typhoid Bacilli in Blood. Conradi, Busquet, Coleman, 

 and Buxton, and others have found the bacilli in the blood of 

 every patient by the following method. A mixture of ox-bile, 

 90 c.c., glycerin, 10 c.c., and peptone, 2 gm., is distributed into 

 20 c.c. flasks and sterilized. Ten cubic centimeters of blood is 

 drawn from the elbow into a glass syringe and divided among 

 three flasks. These are incubated, and in twenty-four hours 

 litmus-lactose agar plates are inoculated on the surface by a 

 stroke from the flasks. A growth is obtained in five or six 

 hours. 



If the growth is a bacillus which has not reddened the 

 medium, it is tested for the Widal reaction with immune 

 serum. The diagnosis has been made as early as the second 

 day. 



Paracolon or paratyphoid bacilli are members of the colon 

 group recently described by Widal, Gwyn, Schottmiiller, and 

 others. They are of importance, since they produce fevers 

 clinically resembling a mild form of typhoid, but which are 



