Real-time PCR to detect Erwinia amylovora
Studies were done in Germany to develop a real-time PCR for the detection of Erwinia amylovora (EPPO A2 list). Specific primers were created from a DNA fragment of the common plasmid (pEA29). 11 isolates of E. amylovora from various geographic locations were successfully detected with this method, but not 8 strains belonging to other species of plant bacteria. E. amylovora could be detected in inoculated apple leaves and flowers and also from leaf and bark tissues collected from an infected orchard. It is considered that real-time PCR is highly sensitive and specific, less time-consuming than other PCR assays, and that is allows a quantitative determination of the amount of cells of E. amylovora in the assay. In addition, portable thermocyclers can be used directly in the field. Although still expensive (price of the machine and probe), real-time PCR may be very useful for screening large amounts of samples and obtaining quantitative data.
Sources
Salm H, Geider K (2004) Real-time PCR for detection and quantification of Erwinia amylovora, the causal agent of fireblight.
Plant Pathology, 53(5), 602-610.