THE PHILIPPINE 



Journal of Scienc 



B. Tropical Medicine 



Vol. XI JULY, 1916 No. 4 



THE RELATION BETWEEN THE AMOUNT OF CHOLERA CULTURE 



INJECTED INTO THE GALL BLADDER AND THE STATE OF 



CHOLERA CARRIERS IN EXPERIMENTAL ANIMALS 



By Otto Schobl 

 (From the Biological Laboratory, Bureau of Science, Manila, P. I.) 



In the work on experimental cholera carriers the following 

 question naturally presented itself : What relation exists between 

 the amount of cholera vibrios injected into the gall bladder and 

 the state of cholera carriers in experimental animals ? In prev- 

 ious experiments ^ the amount injected was considerable — ^that 

 is, one tenth of one slant. Under such conditions all inoculated 

 guinea pigs were positive up to the thirteenth day, inclusive. 

 It remained to be decided whether the number of "takes" would 

 be as high as that, if a smaller amount of cholera culture be 

 injected, and whether or not the duration of the carrier state 

 would be affected by the variation of the amount of cholera 

 injected into the gall bladder. The following experiments were 

 arranged so that amounts of cholera culture varying from 1/80 

 to 1/100,000,000 of a slant were injected. The animals of one 

 lot were killed ^ on the seventh and those of another lot on the 

 thirteenth day after inoculation. 



From these experiments it is evident that the amount of chol- 

 era culture injected into the gall bladder can be decreased con- 

 siderably and still all of the inoculated animals will become 

 carriers. In our experiments the inoculum was decreased from 

 1/80 to 1/80,000 of one slant. The percentage was just as high 

 as it was when 1/10 of a slant was inoculated. When the inocu- 

 lum was diluted beyond this limit, the results became irregular. 

 Animals that received 1/100,000 and 1/10,000,000 of a slant, 

 respectively, were found negative, while the animal that was 

 inoculated with 1/100,000,000 of a slant was found positive. 



Vowrw. Inf. Dis. (1916), 18, 307-314. » Op. cit. 



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