SOURCES OF CONTAMINATION. 



35 



the minced meat and body contents of the same oysters. The results 

 further show that the liquor contained eight tunes as many B. coli 

 per cubic centimeter as the minced meat. 



TABLE 11. The relative number of organisms in oyster and clam meat and liquor samples 

 on plain nutrient and on saltless agar at 25 and 37 C. 



Approximate average of oyster meat at both temperatures 26,000 organisms per cubic centimeter. 



Approximate average of oyster liquor at both temperatures 102,000 organisms per cubic centimeter. 



Approximate average of clam meat at both temperatures 31, 000 organisms per cubic centimeter. 



Approximate average of clam liquor at both temperatures 67, 000 organisms per cubic centimeter. 



The general averages show nearly three times as many organisms 

 per given volume for the liquor of oysters and of clams as for the 

 same volume of meat substance. This explains the fact claimed by 

 practical oystermen that the liquor spoils before the meat of shellfish. 



CHARACTER OF CONTAINERS. 



The proper cleansing and sterilization of utensils and containers is 

 essential to insure freedom from contamination. Single-shipment 

 cans properly handled are less liable to harbor objectionable bacteria 

 than are those packages used for more than one shipment; however, 

 there is no objection to using the latter if they are free from bacteria. 

 Cans are often returned to the shipper in very bad condition, and 

 unless well scrubbed and sterilized they may become a source of 

 danger. By the use of single-shipment packages and a plentiful 

 supply of boiling water there should be no difficulty experienced 

 from unclean vessels. After cleansing and sterilization cans should 

 be inverted or otherwise protected against the entrance of dust, 

 which nullifies the good done by sterilization. 



Progressive oystermen now agree that the best method of shipping 

 oysters is in sealed packages with no ice in contact with the goods. 

 This method prevents contamination from impure ice and protects 

 the oysters in a better manner during shipment than did the old 

 style of tub with ice in contact. The series of shipping experiments 

 made fully demonstrated the superiority of the more modern 

 method. 



