46 Report of the Bacteriologist of the 



some time, one would be led to suppose that the production of 

 color is connected with the activity of some form of life in the 

 cheese. The truth of this supposition was confirmed in 1897 by 

 Connell,^ who isolated from a rusty spot cheese an organism 

 which he called Bacillus rudensis. He showed the causal I'eh'.- 

 tion of this bacterial form by using a starter made from it in 

 the manufacture of cheese in wdiich these rusty spots later ap- 

 peared. 



In our own experiments we have repeated this with organisms 

 derived from outbreaks in different factories. The evidence 

 seems to be conclusive that the red spots are produced by the 

 growth of a minute plant which finds its way into the curd be- 

 fore it is put to press. 



HOW DOES this BACTERIUM GET INTO THE VAT. 



In the factory studied by Dr. Connell, the drain leading from 

 the factory was found coated with a reddish-yellow slime which 

 contained the organism causing the discoloration in the cheese. 

 Upon giving the factory a thorough cleansing, washing the floor 

 and woodwork with disinfecting solution, whitewashing the in- 

 side walls and replacing the wooden drain with an iron one, the 

 trouble disappeared. From the fact that this attempt at disin- 

 fection covered all the available points about the factory, no 

 substantial conclusion can be drawn as to the particular road 

 through which the bacteria gained entrance to the curd. The 

 one fact that seems evident is that in this instance the source 

 of the infection was located at the factory rather than upon the 

 farms. 



In a number of New York factories an honest attempt has 

 been made to meet all the demands of cleanliness and still this 

 discoloration continues in the cheese. While the source of in- 

 fection and methods of distribution of this trouble remained in 



"Connell, W. T. Discoloration of Clieese. Canadian Dept. of Agr., Bui., 

 1897. 



