Occurrence and survival of indicator/pathogenic bacteria in kusaya gravy

Coliform group bacteria, Staphylococcus aureus , salmonella and proteus were not detected in four samples of kusaya gravy, a kind of brine used for the production of special salt-dried fish in Japan. Vibrio parahaemolyticus at a level of 10¹/ml was presumptively detected only in one sample. When inoculated into the gravy at a level of 10⁷-10⁸/ml, none of these bacteria grew. Vibrio parahaemolyticus, Escherichia coli and Proteus morganii rapidly decreased in number and were not detectable after 5 d. Staphylococcus aureus numbers reduced only 1 log cycle after incubation for 7 d in the gravy. These results indicate the safety of the gravy with respect to the organisms.