MSP (Modified Sucrose Peptone) medium is a suitable medium for the detection of Pseudomonas savastanoi pv. phaseolicola (Pspha) and Pseudomonas syringae pv. syringae (Pss). Addition of bromothymol blue gives this medium a blue appearance. The color of bacterial colonies is influenced by this compound. The assay starts with dilution plating of bacterial extract from seeds on MSP. Then suspected colonies from MSP can be transferred to KingÂ’s B Medium (K5165). Finally, the identity of suspected isolates is confirmed by a pathogenicity test or PCR. Colonies of Pspha and Pss are ca. 3 mm in diameter, circular, raised, globose, glistening and light yellow with a denser centerThe medium around Pspha colonies turns light yellow after three days of incubation. For detailed information about DuchefaÂ’s Phytopathological media have a look at our specialized brochure about this topic. Brochure can be found at the Â“Brochure sectionÂ” at the home page of this website.