Reproducibility study for the detection of Staphylococcal enterotoxins in dairy products between official Italian national laboratories

J Food Prot. 2014 Jun;77(6):999-1004. doi: 10.4315/0362-028X.JFP-13-291.

Abstract

Staphylococcal food poisoning is a common foodborne disease caused by the ingestion of staphylococcal enterotoxins (SEs) produced mainly by enterotoxigenic strains of Staphylococcus aureus. To date, 21 SEs and/or enterotoxin-like types have been identified, several of which represent a potential hazard for consumers. To protect consumer health and to reduce the amount of SE-contaminated food entering the market, European Union legislation regulating food safety requires testing for SEs. The Italian National Reference Laboratory organized a ring trial to test technical and analytical proficiency in the national network of official food laboratories. Twenty-four laboratories took part, and each received and analyzed 24 blind dairy samples. Reproducibility of the results from the laboratories was assessed by the Cohen k index, and accuracy (sensitivity and specificity) was evaluated according to the International Organization for Standardization definition (ISO 16140:2003). Trial results revealed partially satisfactory agreement: 254 of 276 possible paired participants (92%) reached a k value >0.60, which is conventionally recognized as satisfactory. Accuracy was deemed satisfactory; 100% sensitivity and 100% specificity were achieved by 22 and 18 of the 24 laboratories, respectively.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dairy Products / analysis
  • Dairy Products / microbiology*
  • Enterotoxins / analysis*
  • Enterotoxins / metabolism
  • Food Contamination / analysis*
  • Food Microbiology / standards*
  • Humans
  • Italien
  • Laboratories / standards*
  • Reproducibility of Results
  • Staphylococcal Food Poisoning / microbiology
  • Staphylococcal Food Poisoning / prevention & control*
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / isolation & purification
  • Staphylococcus aureus / metabolism*

Substances

  • Enterotoxins