OCR Text |
Show NUMBER OF BACTERIA IN MILK UNCERTAIN The test for clean milk most commonly com-monly used is the "bacterial conut." This establishes the number of bac-ever, bac-ever, must be interpreted for milk, (about 15 drops). These counts, however, how-ever, must be interpreted for milk Milk is a good culture medium and develops large numbers of bacteria, mostly harmless lactic acid producing organisms. The numbers found in milk depend upon three things; initial ini-tial contamination, the temperature at which the milk has been held and the age of the milk. Bacterial counts of the same milk are apt to vary some when made in different laboratories labor-atories or even in the same laboratory. labora-tory. Therefore the counts should be interpreted from a series of not less than four or five samples from a given producer and an estimate i should be made of the probable ! source of the bacteria found. Different cities have established . standards of maximum bacteria per-j per-j mined and these standards vary from i 50,000 to 500,000 for each cubic cent-I cent-I imeter and yet it may be that 'milk containing 1,000,000 bacteria to the j cubic centimeter would be safe to use and one containing only 5,000 ' would be followed try a trail of ty- phoid or scarlet fever among its con-i con-i sumers. The bacterial count proves j to be of uncertain value unless a I knowledge of the process through S which the milk has passed and its . contaminating influence are also known. E. G. Carter, assistant professor pro-fessor of bacteriology, Utah Agricultural Agricul-tural College. |