Detection and Identification of $\beta$-lactamase, Enterotoxin and Other Exotoxins Genes of Staphylococcus aureus by PCR

  • Yoon, Y.H. (Department of Animal Science and Technology, College of Industrial Sciences, Chung-Ang university) ;
  • Kim, K.I. (Department of Animal Science and Technology, College of Industrial Sciences, Chung-Ang university)
  • Received : 2002.08.26
  • Accepted : 2002.11.04
  • Published : 2003.03.01


Staphylococcus aureus is a major pathogen for cattle, causing various forms of subclinical and clinical mastitis and could be a causative agent of food poisoning, it produces various superantigenic exotoxins which have a great public health significance. A total of 72 S. aureus clinical isolates from dairy farms located in Kyunggi Province Korea were examined for the species identification by biochemical method, and for the detection of $\beta$-lactamase, enterotoxin and other exotoxins genes by PCR. The results of species identification by biochemical method agreed with those of PCR done with species specific primer STA-AU. $\beta$-lactamase is an enzyme closely associated with the resistance to antibiotic penicillin, which is an important means of treatment of mastitis, all the isolates were positive for the presence of genes encoding $\beta$-lactamase, which were reproduced in penicillin susceptibility disc assay. Six types of toxin genes, Staphylococcal enterotoxin (SE)A, SEB, SEC, SEE, toxic shock syndrome toxin (TSST-1) and exfoliative toxin A (ET A) were detected in 72 isolates by PCR associated genotypic method in this study, none of the isolates carried the genes for enterotoxin D (SED) and exfoliative toxin B (ETB). The occurrence rate of exotoxin genes rated as 12.5%, and the precision of the PCR identification results has been confirmed using the reference strains.


  1. Coia, J. E., F. Thomson-Carter, D. Baird and D. J. Platt. 1990. Characterization of Methicillin resistant Staphylococcus aureus by biotyping, immunoblotting and restriction enzyme fragmentation patterns. J. Med. Microbiol. 31:125-132.
  2. Fueyo, J. M., M. C. Martin, M. A. Gonzalez-Hevia and M. C. Mendoza. 2001. Enterotoxin production and DNA fingerprinting in Staphylococcus aureus isolated from human and food samples. Relations between genetic types and enterotoxins. International J. Food Microbiol. 67:139-145.
  3. Stephan, R., C. Annemuller, A. A. Hassan and Ch. Lammler. 2001. Characterization of enterotoxigenic Staphylococcus aureus strains isolated from bovine mastitis in north-east Switzerland. Veterinary Microbiology 78:373-382
  4. Thompson, N. E., M. Razdan, G. kunstmann, J. M. Aschenbach, M. L. Evenson and M. S. bergdoll. 1986. Detection of stphylococcal enterotoxins by enzyme linked immunosorbent assays and radioimmunoassays; comparison of monoclonal and pllyclonal antibody systems. Appl. Environ. Microbiol. 51:885-890.
  5. Zshock, M., D. Botzler, S. Blocher, J Sommerhauser and H. P. Hamann. 2000. Detection of genes for enterotoxins (ent) and toxic shock syndrome toxin-1 (tst) in mammary isolates of Staphylococcus aureus by polymerase-chain-reaction. Int. Dairy J. 10:569-574.
  6. Betley, M. J. and J. J. Mekalanos. 1988. Nucleotide sequence of the type A staphylococcal enterotoxin gene. J. Bacteriol. 170:34-41.
  7. Onoue, Y. and M. Mori. 1997. Amino acid requirements for the growth and enterotoxin production by Staphylococcus aureus in chemically defined media. Int. J. Food Microbiol. 36: 77-82.
  8. Larsen, H. D., F. M. Aarestrup and N. E. Jensen. 2002. Geographical variation in the presence of genes encoding superantigenic exotoxins and -hemolysin among Staphylococcus aureus isolated from bovine mastitis in Europe and USA. Veterinary Microbiology 85:61-67.
  9. Johnson, W. M., S. D. Tyler, E. P. Ewan, F. E. Ashton, D. R. Pollard and K. R. Rozee. 1991. Detection of genes for enterotoxin, exfoliative toxins, and toxic shock syndrome toxin in Staphylococcus aureus by the Polymerase Chain Reaction. J. Clinical Microbiol. 29(3):426-430.
  10. Rasooly, A. and R. S. Rasooly. 1998. Detection and analysis of Staphylococcal enterotoxin A in food by Western immunoblotting. Int. J. Food Microbiol. 41:205-212.
  11. Blanban, N. and A. Rasooly. 2000. Staphylococcal enterotoxins. Int. J. Food Microbiol. 61:1-10.
  12. Hackbarth, C. J., T. Kpcagoz, S. Kocagoz and H. F. Chambers. 1995. Point mutations in Staphylococcus PB2 gene affect penicillin-binding kinetics and are associated with resistance. Antimicrob. Agents Chemother. 39:103-106.
  13. Alatossava, V., A. Meindl and D. Ring. 2001. Prevalence of Staphylococcus aureus and staphylococcal enteritoins in raw pork and uncooked smoked ham-a comparison of classical culturinjg detection and RFLP-PCR. Int. J. Food Microbiol. 68:105-113.
  14. Junes, C. L. and S. A. Khan. 1986. Nucleotide sequence of enterotoxin B gene from Staphylococcus aureus. J. Bacteriol. 166:29-33.
  15. Ali-Vehmas, T., P. Westphalen, V. myllys and Sandholm. 1997. Binding of Staphylococcus aureus to milk fat globules increases resistance to penicillin-G. J. Dairy Res. 64:253-260.
  16. Schochetmann, G., C. Y. Ou and W. K. Jones. 1988. Polymerase chain reaction. J. Infect. Disease 158:1154-1157.