REPORT OF THE DEPARTMENT OF 
BACTERIOLOGY. 
BON ROTO rR sRTS TyeSROT. IN) CHEBSE 
PAC TORIES” 

H. A. HarpInG AND G. A. SMITH. 

SUMMARY. 
(1) Rusty spot in cheddar cheese is present in the output of 
a number of factories in this State. 
(2) The rusty spots are caused by the growth in the cheese of a 
red bacterium, just as green streaks in stale bread are caused by 
the growth of a green mold. 
(3) The trouble is most evident in moist home-trade cheese. 
(4) The use of cheese color can not be relied upon to entirely 
disguise the red spots. 
(5) Steaming the factory utensils as a means of combating 
this trouble has been tried in a number of infected factories 
during the past two seasons. 
(6) The results thus far show that this treatment applied 
thoroughly three times per week will prevent financial loss except 
under very unusual conditions. 
(7) While under ordinary conditions the factory seems to be 
the main seed bed of the germs, cheeses made from the milk of in- 
dividual patrons indicate that at times the milk of some patrons 
contains the germs causing rusty spots. 

*A reprint of Bulletin No, 225, 
