Studies on various strains of Erwinia amylovora
Studies were carried out in France and Germany on 127 strains of Erwinia amylovora (EPPO 2 quarantine pest) isolated from different hosts (fruit trees and ornamentals) and from various origins (Austria, Belgium, Bulgaria, Canada, Denmark, France, Germany, Greece, Ireland, Israel, Netherlands, New Zealand, Poland, Sweden, Switzerland, Syria, Turkey, UK, USA). By using PCR and restriction enzymes, some variability between strains could be observed, although E. amylovora has so far been considered as a rather homogeneous species. Strains could be separated into 3 groups according to the length of the DNA products. Most of the strains were included into 2 groups, and no relations could be found with hosts or origin. However, 13 strains could be clustered into a 3rd group. These strains were all isolated from recent foci in Austria and Southern Bavaria (Germany). The authors noted that this polymorphism could be used as an epidemiological marker to trace the spread of fireblight in Central Europe.
Sources
Lecomte, P.; Manceau, C.; Paulin, J.P.; Keck, M. (1997) Identification by PCR analysis on plasmid pEA29 of isolates of Erwinia amylovora responsible of an outbreak in Central Europe.
European Journal of Plant Pathology, 103(1), 91-98.