AN AEROBIC SPORE-FORMING BACILLUS GIVING GAS IN LACTOSE BROTH ISOLATED IN ROUTINE WATER EXAMINATION

Abstract

In the course of routine water examinations at this station, the writer has, on several occasions, isolated aerobic lactose-fennenting organisms which have been demonstrated to be spore-forming. So far as can be ascertained by a fairly complete review of the published literature, there has been no such organism previously described.' In water work two large groups of bacteria generating gas from lactose are recognized. The first are the aerobic non-spore-forming bacilli of the coli-aerogenes group, and the second the anaerobic spore-forming bacilli of the sporogenes group. The significance of the presence in a water of members of either of these groups has been pretty well established. The organism tQ be described lies midway between these two groups, in that it is aerobic as well as spore-forming. Just what its sanitary significance is, remains to be established. ISOLATION It has been the routine procedure in this laboratory to isolate for study one culture of B. coli from each sample of water examined. This is effected by carefully fishing one isolated colony l Since this article went to press, the writer has come across an article on systematic bacteriology of water by S. De M. Gage and E. B. Phelps in Am. Pub. Health Ass. Rep. 1902, 28, 402, 412. In the table given in this article a few cultures are noted as being aerobic lactose fermenters. In the opinion of Mr. Gage it is very unlikely that the organism now being described could be among those described by him. 9