Articles
IDENTIFICATION OF ERWINIA AMYLOVORA BY PCR-ANALYSES
Primers were created from a 0.9 kb Pstl-fragment of the common plasmic pEA29. After cell lysis with Tween 20, about 50 bacteria could be detected.
Recently, we amplified a chromosomal fragment from the ams-region, which produced a specific signal for different Erwinia amylovora strains assayed.
The amplified fragment of 1.6 kb was sequenced and found identical for two E. amylovora strains.
The strict requirement of the EPS-capsule for pathogenicity and the unique sugar linkages in amylovoran suggest that the ams-genes are indispensable and highly conserved for E. amylovora. The amplification of information from the ams-region could also be used for detection of the fire blight pathogen in the presence of other bacteria and from plant tissue.
An additional PCR assay to identify E. amylovora was performed with 16S rDNA and subsequent digestion of the product with restriction enzyme Haelll. When this assay was done with DNA from other bacteria, the band pattern was different from that of E. amylovora. Finally, arbitrarily primed (AP)-PCR produced a pattern of bands which was specific for Erwinia amylovora. Both methods require homogenous bacterial cultures or DNA preparations for identification of the fire blight pathogen.