Genetic fingerprinting of Pseudomonas syringae pathovars using ERIC-, REP-, and IS50-PCR

PCR fingerprinting using primers corresponding to repetitive (ERIC and REP) and insertion sequences (IS50) was investigated as a method to distinguish the pathovars of Pseudomonas syringae. After amplification of total DNA with the ERIC-, REP-, and IS50-PCR followed by agarose gel electrophoresis, most of the tested pathovars showed specific patterns of PCR products. The differences between the fingerprints among strains within a pathovar were small, with the exception of pathovars syringae, aptata, and atrofaciens. The fingerprints of the related pathovars savastanoi, phaseolicola, glycinea, morsprunorum, tabaci, lachrymans, and mori generated with the ERIC- and REP-primers were found to be very similar, showing the potential of this technique for taxonomical studies. In contrast, the IS50-PCR fingerprints of these pathovars were clearly distinguishable. The fingerprint patterns of a strain were highly reproducible with all three tested primer sets, also when whole cells were added to the reaction mixture. Thus, the PCR technique with the ERIC-, REP-, and IS50-primers is a rapid, simple, reproducible, and low cost method to identify and classify strains of the Pseudomonas syringae pathovars.