Ring test on diagnostic methods for Erwinia stewartii ssp. stewartii (Pantoea stewartii ssp. stewartii)

For the EU member states there is no harmonized diagnostic method for Erwinia stewartii ssp. stewartii (Pantoea stewartii ssp. stewartii). The EPPO protocol PM 7/60 (1) lists several tests for the first investigation and the following isolation/screening and identification. These tests haven’t been tested in ring tests so far. For the preliminary examination, isolation, IF, ELISA and conventional PCR were proposed. The EPPO protocol contains no information on sensitivity, specificity and reproducibility. In addition, naturally infested seeds were not used for the development of these protocols. Newly available methods as real-time assays were also considered for inclusion in the ring test. The research aims of the project were validation and standardisation of the diagnostic methods used by national plant protection services and other relevant laboratories, considering detection and identification methods by ring testing. The ring test allowed to: 1. Determine sensitivity, specificity and reproducibility of the different methods. 2. Compare different media for the isolation of the bacteria, and compare isolation with other tests, using artificially contaminated seed. 3. Test sensitivity, specificity and reproducibility of the results of methods used so far (IF and ELISA) and the PCR (with previously released primers) with naturally infected seed, or with artificially contaminated samples if naturally infected seeds.