In the current study, molecular typing of 50 Erwinia amylovora strains related to different regions in Iran was evaluated using multi-locus sequence analysis and variable number of tandem repeats. In the first assay, phylogenetic tree based on partial sequences of recombinase A, sigma factor S and a heat shock protein GroEL showed significant identity in studied gene sequences. A single nucleotide variation in groEL was determined in IrGh59 strain related to Crataegus spp. from Ghazvin province. In VNTR analysis, the same fingerprinting profile similar to E. amylovora reference strain ATCC49946 was yielded for tested strains except NBQ1 and MQ1 which may reflect a unique contaminating source for this disease in Iran. In addition, the honey-bee movements with respect to blossom season probably have considerable role in fire blight unique dispersal in our area. The NBQ1and MQ1 strains generated different VNTR profiles, isolated from cultivars Neishabour and Esfehan of Cydonia oblonga plant, respectively. No definite assessment can be expressed in this case. However, possible entry of other infection mass from neighboring countries should be determined. Overall, VNTR profiles analysis are recommended as a tool to evaluate genetic differences in E. amylovora populations. In addition, employing more strains from different known sources can be assisted to achieve more accurate results about E. amylovora genetic variation and also fire blight distribution patterns.

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