BACTERIA IN DIPHTHERIA. 



Biological Characters. An aerobic, non-liquefying (non -motile ?) ba- 

 cillus. Upon gelatin plates semi-transparent, grayish colonies are formed, 

 which later have a brownish color; the surface of these is finely granular 

 and of a pearly lustre. In stick cultures in nutrient gelatin the growth 

 along the line of puncture is very scanty. On potato a flat, whitish layer is 

 formed, which extends slowly over the surface. Grows best at a temperature 

 of ;;u t..:{;V C. 



Pathogenesis.PurQ cultures injected into the peritoneal cavity or sub- 

 cutaneously in rabbits caused the death of these animals in from three to 

 fourteen days, according to the quantity injected. At the autopsy necrotic 

 foci are found in the liver and spleen, and the mesenteric glands are en- 

 larged, but the intestine presents a healthy appearance. But when cultures 

 are introduced into the alimentary canal the characteristic diphtheritic in- 

 flammation of the mucous membrane of the intestine is induced. This re- 

 sult was obtained both by direct injection into the lumen of the intestine 

 and by injecting cultures into the mouth. 



Additional Notes upon Diphtheria and the Diphtheria Bacil- 

 lus. C. Frankel (1895) reports that he has repeatedly observed 

 branching forms of the diphtheria bacillus in cultures upon Lof- 

 fler's blood-serum medium, and that these branching forms are seen 

 more constantly and in greater numbers in cultures made upon the 

 surface of hard-cooked albumen from hen's eggs. 



The continued presence of virulent diphtheria bacilli in the fauces 

 of patients who have recovered from the disease, either after the use 

 of the antitoxin or under other treatment, has been demonstrated by 

 several bacteriologists. Silverschmidt (1895), in forty-five cases 

 treated by Behring's antitoxic serum, found that the number of ba- 

 cilli usually diminished some days after the treatment was com- 

 menced, but that in cases in which complete recovery had taken 

 place not infrequently virulent bacilli could be obtained many days 

 (in one case thirty-one days) after convalescence was established. 



Escherich (1893) opposes the view that the pseudo-diphtheria bacil- 

 lus is simply a non-virulent variety of the diphtheria bacillus. He 

 found this pseudo-diphtheria bacillus in the throats of thirteen out 

 of three hundred and twenty individuals examined. According to 

 lii in there is no evidence that this completely non-virulent pseudo- 

 diphtheria bacillus ever acquires pathogenic virulence, while attenu- 

 ated varieties of the true diphtheria bacillus readily recover their 

 power to produce the toxic products upon which virulence depends. 



Sevestre (1895), as a result of researches made by himself and 

 several other bacteriologists who have made similar investigations, 

 arri ves at the conclusion that : 



"First. In a <vrtain number of cases the bacillus of Loffler disap- 

 pears about the same time as the false membranes; or it may persist 

 t'<>r sum.- time, but ceases to be virulent in this case it seems to have 

 undergone modifications and presents tbe form of short bacilli. 



" Second. In another series of cases, less numerous but neverthe- 



