Diagnosis of bacteria is mostly performed through screening tests which include Gram Staining, Immunofluorescence assays and culturing of bacteria on semi-selective media. Additional and confirmatory tests include Polymerase Chain Reaction and inoculation on indicator plants. Priority diseases are Clavibacter michiganensis spp sepedonicus, Ralstonia solanacearum and Xylella fastidiosa. Potato Ring Rot and Potato Brown Rot are the two main pathogens which, if introduced, pose a serious threat to potato cultivation, which is one of the most economically important crops in the Maltese islands. Identification is either done locally or abroad as necessary.

 Example of Bacterial cultures of Ralstonia

The Diagnostic laboratories are also conducting routine testing on samples collected from trade and from local territory for Xylella fastidiosa, which can have a destructive impact on various species of local plants/trees.  The diagnostic laboratories conduct screening tests (DAS-ELISA), in conjunction with Real-Time PCR testing (the latter being outsourced), as per EPPO standard PM7/24.