﻿414 STRONG. 



faeces examined, and in 304 autopsies performed by members of the labor- 

 atory staff on cases supposed to have died of cholera, the diagnosis of this 

 disease was confirmed in 260; 129 specimens of drinking water, collected 

 from reservoirs, wells and other sources of supply were also sent to be 

 examined for infection with the cholera spirillum, but from only 3 of 

 these was this organism isolated. 



METHODS EMPLOYED IN THE BACTEEIOLOGIO DIAGNOSIS. 



Several methods were employed in performing the bacteriologic 

 diagnosis from the faeces, an attempt being made in each instance to 

 secure as prompt a result as possible. All methods which were not based 

 upon the isolation of a pure culture of the cholera organism to be 

 employed in the subsequent tests proved at times to be untrustworthy. 

 The one which was demonstrated to be perfectly reliable in practically 

 all acute cases and by means of which, in addition, a definite diagnosis 

 could usually be reached within six to eight hours and almost invariably 

 in from sixteen to eighteen hours, was as follows: Numerous alkaline 

 agar plate cultures were prepared directly from the cholera stools, some 

 being inoculated with large and others with small portions of the faeces, 

 various dilutions being prepared ; the cultures were placed at 37° C. and 

 as soon as the colonies became sufficiently developed, those which re- 

 sembled colonies of the cholera spirillum were suspended in saline solu- 

 tion. Agglutinative and bacteriolytic tests by the microscopic method 

 were then performed with them and a standard fresh cholera serum in 

 proper dilutions. The morphology and motility of the organism were 

 also noted. Frequently, after twelve to sixteen hours from the time 

 of the inoculation of the plates, sufficient growth was obtained in addi- 

 tion to carry out the Pfeiffer bacteriolytic test with the same cholera 

 serum, in the abdominal cavity of a guinea pig. This method frequently, 

 although not invariably, proved to be the quickest means by which a 

 diagnosis could be made, and the preparation of the plate cultures 

 from the suspected faecal material soon became a routine one in the 

 laboratory. In case a positive diagnosis was reached by methods re- 

 quiring a briefer period of time, the subsequent agglutinative and 

 bacteriolytic tests by the first described method were not always per- 

 formed, but if a negative result was obtained by the briefer procedures, 

 then these tests were carried out and they sometimes finally resulted in 

 establishing a diagnosis of cholera. 



Another method which frequently could be relied upon for diagnosis 

 in case of a positive result, consisted in making the inoculations from 

 the stool directly into tubes of 2 per cent peptone solution and of the 

 performance of the agglutinative test by the microscopic method with 

 drops of this medium taken from the surface and added to a cholera 



