454 Diphtheria 



Welch and Abbott found that Weigert's fibrin method and 

 picrocarmin gave the most beautiful results. 



Cultivation. The diphtheria bacillus grows readily upon 

 all the ordinary media, and is very easy to obtain in pure 

 culture, plates not being necessary. Material from the in- 

 fected throat can be taken with a swab or platinum loop 

 and spread upon the surface of several successive tubes 

 of Loffler's blood-serum media. Upon the first a confluent 

 growth of the bacillus usually occurs; but upon the third, 

 scattered colonies suitable for transplantation can usually 

 be found. 



Loftier has shown that the addition of a small amount 

 of glucose to the culture medium increases the rapidity of 

 growth, and suggests a special medium which bears his 

 name Loffler's blood-serum mixture: 



Blood-serum . % 3 



Ordinary bouillon + 1 per cent, of glucose .... 1 



This mixture is filled into tubes, coagulated, and sterilized 

 like blood-serum, and is one of the best known media to be 

 used in connection with the study of diphtheria. 



The studies of Michel * have shown that the development 

 of the culture is much more luxuriant and rapid when 

 horses' serum instead of beef or calves' serum is used. 

 Horse's blood can easily be secured by the introduction of 

 a trocar into the jugular vein ; 5 liters of it can be withdrawn 

 without causing the animal inconvenience or symptoms of 

 weakness. 



Westbrook suggested that the addition of a small amount 

 of glycerin to the preparation of blood-serum would prevent 

 it from drying so rapidly as usual and would have the added 

 advantage of preventing the growth of certain varieties 

 of bacteria not desired. Duboisf carried out a series of 

 observations upon this question and found that 3 to 5 

 per cent, of glycerin makes a very valuable addition, as 

 the diphtheria bacilli grow very rapidly and almost in 



* "Centralbl. f. Bakt. u. Parasitenk.," Sept. 24, 1897, Bd. xxn, 

 Nos. 10 and u. 



t "Seventeenth Annual Report of the Department of Health and 

 Charities," Indianapolis, Ind., 1907. 



