Recent examination of the relationships of the dry necrosis-inducing (necrogenic) erwinias using 16S rDNA sequences demonstrated that these bacteria comprise a polyphyletic group and, therefore, have been subdivided into three distinct genera, Erwinia, Brenneria and Pectobacterium, with the classical 'amylovora' group species now being distributed nearly evenly among the first two. To further a...

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 nucleot...

Erwinia amylovora causes a devastating disease called fire blight in rosaceous plants. The type III secretion system (T3SS) is one of the important virulence factors utilized by E. amylovora in order to successfully infect its hosts. By using a green fluorescent protein (GFP) reporter construct combined with a high-throughput flow cytometry assay, a library of phenolic compounds and their deriv...

ABSTRACT Fire blight of apple and pear is initiated by epiphytic populations of Erwinia amylovora on flower stigmas. Predicting this disease and managing it with microbial antagonists depends on an understanding of bacterial colonization on stigmas. Detached 'Manchurian' crab apple flowers were inoculated with E. amylovora and subjected to a range of constant temperatures or various fluctuating...

The "disease-specific" (dsp) region next to the hrp gene cluster of Erwinia amylovora is required for pathogenicity but not for elicitation of the hypersensitive reaction. A 6.6-kb apparent operon, dspEF, was found responsible for this phenotype. The operon contains genes dspE and dspF and is positively regulated by hrpL. A BLAST search revealed similarity in the dspE gene to a partial sequence...

ABSTRACT Detached crab apple flowers were used as an experimental model to investigate the effect of relative humidity (RH), free moisture, and water potential Psi(w) on the interaction between Erwinia amylovora and pomaceous flowers. Flowers were maintained at 24 degrees C with the cut pedicel submerged in a sucrose solution. The bacterium multiplied on inoculated flower stigmas at between app...

ABSTRACT The addition of 0.1 mM FeCl(3) to a defined culture medium induces the bacterial epiphyte Pseudomonas fluorescens strain A506 (A506) to produce an antibiotic toxic to the fire blight pathogen, Erwinia amylovora. Consequently, because A506 is registered and applied as a commercial product to suppress E. amylovora before floral infection of pear and apple, the relative availability of ir...