1972 Volume 13 Issue 5 Pages 392-397
Ten kinds of frozen ready-to-serve sea-food were investigated bacteriologically. As the results, almost all samples were found to contain living cells of E. coli, Enterococci and Staphylococci, however, Vibrio parahaemolyticus, Salmonella and Shigella could not be isolated.
Among staphylococcal strains isolated from shellfish (Neptunea polycostata), two strains produced enterotoxic substances. One strain produced enterotoxin A, B and D, while another enterotoxin B and D. The production of these toxins were evidenced by precipitation against antienterotoxins and monkey feeding tests.
A refference strain of enterotoxigenic Staphylococcus aureus (S-6) produced more than 3.8 microgram of enterotoxin B in one gram of this kind of shellfish after incubation for 8 hours at 37°C. It seems that this amount of enterotoxin is enough to provoke food poisoning symptoms in adult when it is consumed.
It was confirmed experimentally that it needs boiling for ten minutes to sterilize frozen shellfish (Neptunea polycostata), completely.
