Articles
ISOLATION AND CHARACTERIZATION OF ERWINIA AMYLOVORA FROM AUSTRALIAN WOOD SAMPLES
Wood samples were removed and investigated for the presence of E. amylovora. Parts of the bark were sliced off and extracted in water.
PCR assays with three different primer pairs were done and aliquots were plated on LB plates.
After two days of incubation white colonies were transferred to selective minimal agar plates for identification of E. amylovora. In addition immature pear slices were inoculated with the extracts.
In three cases, we obtained positive PCR signals with three primer pairs from plant material from the Royal Botanic Gardens (RBG) in Melbourne and, in another case, from a soft agar culture which was prepared in Australia from a wood sample of the same origin.
The isolation of the pathogen was achieved in three of four PCR-positive samples.
Once by plating, and twice by inoculation of immature pears.
The isolated strains were further confirmed as E. amylovora by tests on selective agar plates, lectin staining, PFGE and sequence analysis of the intergenic transcribed rRNA spacer region.
Strains from samples of the Melbourne RBG isolated in Germany or New Zealand revealed the same PFGE pattern.
A difference was found for the length of the amplified fragment with primers from E. amylovora plasmid pEA29. The fire blight pathogen was not detected from any samples obtained from plant material of the Botanic Gardens in Adelaide.