BACTERIOLOGY OF THE OYSTER. 13 



showing all the cultural characteristics of the typhoid bacillus, it 

 also agglutinated in five minutes in a 1:1000 dilution of typhoid 

 immune serum. This organism was isolated from the oysters seven 

 days after they were taken from the water. Later oysters from the 

 same lot were examined after they had been out of the water twenty- 

 one days and kept at 39° F. An organism was isolated which 

 resembled typhoid in all its cultural characteristics and agglutinated 

 macroscopically in a chlution of 1 :1000. This test was confirmed by 

 hanging drop preparations in dilutions of 1 : 200. 



There can be no possible doubt that the organisms isolated by Stiles 

 are true typhoid bacilli, while little can be desired to confirm the 

 identity of the organism isolated by Klein. 



An interesting feature of the work of Stiles is that he demon- 

 strated the typhoid bacillus in oysters which had been infected 

 under natural condition and which had been kept out of water 

 for three weeks. Klein, ^ Foote^ Herdman and Boyce,^ and 

 others have reported instances in which typhoid bacilli have been 

 isolated after varying lengths of time up to 18 days after infection 

 from oysters artificially infected with large numbers of typhoid bacilli 

 in pure cultures or from typhoid stools and kept in sea water in the 

 laboratory. So far as the writer is aware Stiles is the first one to show 

 that oysters infected under normal circumstances with sewage con- 

 taining typhoid bacilli and kept under favorable conditions can still 

 harbor B. typhosus after 21 days. The condition here are somewhat 

 different from laboratory experiments in that in sewage along with the 

 typhoid bacilli are other bacteria whose influence is exceedingly 

 hostile to the growth of B. typhosus.* 



It is interesting to see that this organism has been isolated so few 

 times, in spite of the abundant epidemological evidence in so many 

 instances which points conclusively to the infection of oysters and 

 other shellfish with typhoid bacilli. The reason for this, however, 

 is quite readily understandable when we consider the number of 

 typhoid bacilli which could be found in the sewage of any town or 

 city in comparison with the number of other organisms found in 

 that same sewage. It would be a case of searching for the proverbial 



^Loc. cit. 



^A Bacteriological study of Oysters, with Special Reference to them as a source of Typhoid 

 Infection," 18th Ann. Report Com. State Board of Health. 



'Oysters and Disease, Thompson Yates Laboratory Report, 1-2. 

 ^Jordan, Russell & Zeit, Journal of Infectious Diseases 1, 1904, 641. 



