In this project we aim to setup a country-wide survey protocol for the detection of the quarantine organism R. solanacearum by using surface water samples to obtain an indication of the presence of this pathogen in Switzerland. Together with project collaborator Dr. Helmut Bürgmann at EAWAG Kastanienbaum, we will develop a strategy directed at identifying the best sampling locations, sampling and nucleic acid extraction procedures to maximize the chances of detection, taking into account the geographical distribution of potential hosts and the surface water flows around them. Sampling procedures, sample concentration and detection protocols for R. solanacearum will be selected and developed in order to attain the highest possible sensitivity and specificity at species level without the need to cultivate the bacterium prior to the analysis. Obtaining clear overview of the pathogen’s situation across the country will allow the quick identification of problematical areas for the cultivation of potential host plant, thus facilitating strategical decisions and limiting the necessity of expensive eradication procedures. In parallel, procedures for the quick discrimination of the different phylotypes of R. solanacearum will be established to assess the distribution of the populations present on Swiss territory and to compare them to those previously detected in Europe or worldwide. For the validation of the PCR diagnostic tests, this project includes Santiago Schaerer, Agroscope Changins as a project collaborator to provide a second expert opinion in the development of this monitoring tool. The support of project collaborators Dr. Beat Frey and Dr. Daniel Rigling, who will provide access to BSL-3 facilities at WSL Birmensdorf, will be essential for all the steps of this project for validation with the living organisms.