Characterization of Erwinia amylovora Strains from Croatia

Abstract

Erwinia amylovora is the causative agent of fire blight, a destructive disease of rosaceous plants. The European population can be divided into several subtypes according to differences in restriction fragment length polymorphism of the XbaI genomic DNA digest analysed with pulsed-field gel electrophoresis. This technique was also used to determine the genetic relatedness of six Croatian isolates to the E. amylovora types found in the countries surrounding Croatia. The isolates belong to the Pt2 pattern type that is characteristic of the East Mediterranean basin. All tested isolates gave essentially the same total cell protein pattern in SDS-polyacrylamide gel electrophoresis. The number of short-sequence DNA repeats in plasmid pEA29 of six isolates was determined by PCR assays and ranged from four to seven. The isolates examined showed high pathogenicity in immature pear fruits. Differences were also revealed in microbiological assays such as amylovoran synthesis, levan formation, siderophore production and colour on coliform medium.

Exploring diversity of Erwinia amylovora population in Serbia by conventional and automated techniques and detection of new PFGE patterns

“…Also, three E. amylovora strains from north Serbia had the Pt2 profile in this study, and all three of them were isolated near the border with Croatia. This profile was already discovered in Croatia in two separate studies (Zhang et al 1998;Halupecki et al 2006). E. amylovora was discovered in Croatia in 1995 (Cvjetković et al 1996), 6 years after it was identified in Serbia.…”

Exploring diversity of Erwinia amylovora population in Serbia by conventional and automated techniquesand detection of new PFGE patterns

“…Also, three E. amylovora strains from north Serbia had the Pt2 profile in this study, and all three of them were isolated near the border with Croatia. This profile was already discovered in Croatia in two separate studies (Zhang et al 1998;Halupecki et al 2006). E. amylovora was discovered in Croatia (Cvjetković et al 1996), 6 years after it was identified in Serbia.…”

“…Similar PFGE patterns of E. amylovora strains have been reported in countries neighbouring Serbia: Croatia, Hungary, Bulgaria and Albania. Most strains from these countries had the Pt2 pattern (Zhang et al 1998;Halupecki et al 2006), which grouped them together with the strains from Egypt and Turkey, described previously (Zhang and Geider 1997). However, strains from Serbia were not part of these studies and consequently there were no indications of the pathogen introduction directions and population origin.…”

The status of Erwinia amylovora in the former Yugoslav Republics over the past two decades

“…Conventional laboratory methods were used for identification of isolates (Calzolari et al, 1992) and characteristic colonies were formed on D 3 medium (Kado, 1970). Halupecki et al (2006) studied the population of E. amylovora in Croatia. The isolates were obtained from different hosts in the period from 1998 to 2001.…”