The Enterotoxigenic Types for 62 Staphylococcus aureus Isolates from Raw Milk and Some Other Animal Specimens
CHIEN-CHIH WU1, CENG-PING CHENG2 AND MING-JENG PAN1
1.Graduate Institute of Veterinary Medicine, National Taiwan University
2.Taipei Municipal Institute for Animal Health
ABSTRACT
A commercial ELISA kit (RIDASCREENR SET A, B, C, D, E. R-Biopharm GmbH, Darmstadt, Germany) was used to examine the enterotoxigenecity of 76 Staphylococcus aureus strains. Of these strains, 62 were isolated from raw milk, 3 from whale, 4 from dolphin, 2 from cow milk with mastitis, 2 from pig, and 1 each from chicken, mouse, and dog. Type A, B, and C enterotoxins were detected in 26, 2, and 1 strains, respectively. Neither type D nor type E enterotoxin-producing strain was observed. In addition, DNA amplification by capillary polymerase chain reaction （PCR） with specific primers was used to detect the presence of enterotoxin A gene. The results showed that 26 strains harbored this gene. Study on the detection sensitivity of PCR indicated that the lowest cell number required for positive reaction was 104 CFU/ml.
Key words: Staphylococcal enterotoxins, enzyme-linked immunosorbent assay, polymerase chain reaction