Differences between reference laboratories of the European Community in their ability to detect Salmonella species

The ability of national reference laboratories for Salmonella of the European Union member states to detect Salmonella bacteria was tested in four collaborative studies during the period 1995 through 1999. Three different methods were prescribed in the four studies. Capsules containing various numbers of Salmonella Typhimurium or Salmonella Enteritidis were tested. In studies II, III and IV, Salmonella bacteria were isolated in the presence of competitive microorganisms. Significant differences were found between the four studies due to varying levels of difficulty with regard to the level of contamination, the use of serotypes and the presence of competitive organisms. There were also significant differences between the laboratories in the results obtained. Possible reasons for these differences will be further investigated by the European Union Community Reference Laboratory for Salmonella.