SPORE-FORMING ORGANISM FROM IOWA 341 



The strain resembles markedly that described by Meyer, differing 

 with respect to rate of liquefaction of gelatin, nitrate reduction and 

 the Voges-Proskauer test. 



The organism should be of particular interest to water works 

 operators because of its extreme resistance to chlorination, and be- 

 cause of the ease of confusion with the colon group in routine tests 

 as ordinarily performed. Its presence in water may explain anoma- 

 lous positive colon tests. Information as to its source is particularly 

 desirable. 



The cultures isolated are strikingly similar to B. macerans and 

 B. acetoethylicum. 



NOTE ON PATHOGENICITY 



The Bacillus acetoethylicum of Northrup, Ashe and Senior was 

 reported non-pathogenic to mice. 



One of the similar organisms isolated in the course of this study 

 was tested for pathogenicity on rabbits in the following manner: 



An agar culture was scraped to remove the entire growth on its 

 surface and the material suspended in physiological salt solution 

 and added to the drinking water supplied to a rabbit. This proc- 

 ess was repeated daily for a week. The test animal did not show 

 any untoward symptoms. 



Another rabbit was injected intravenously with one cubic centi- 

 meter of a live culture prepared by removing the growth of organ- 

 isms from an agar slant as indicated above and suspending the 

 material in 10 cc. of sterile salt solution. The animal developed 

 no symptoms that would indicate bacterial infection. 



We are therefore of the opinion that this organism is not a 

 pathogenic form. 



REFERENCES 



ELLMS, JOSEPH W. 1920 Report of experiments in the purification of the 

 water supply of Milwaukee, Wisconsin. 



EWING, C. L. 1919 Presence of a spore bearing aerobic gas forming bacillus 

 in Baltimore city drinking water. Am. Jour. Pub. Health, ix, 157- 

 158. 



HALL, I. C., AND ELLEPSON, L. J. 1918 The elimination of spurious pre- 

 sumptive tests for B. coli in water by the use of gentian violet. 

 Jour. Bact., iii, 329-354. 



HALL, I. C., ANDELLEFSON, L. J. 1919 Further studies on gentian violet 

 as a means of eliminating spurious presumptive tests for B. coli 

 in water. Jour. Am. Water Works Assoc., vi, 67-77. 



