Recent taxonomic revisions have caused the bacteria Erwinia chrysanthemi to be renamed: Dickeya dadantii. D. dadantii is a gram-negative bacillus that belongs to the family Enterobacteriaceae. It is a close relative of E. coli and other animal pathogens that include Salmonella, Shigella, Klebsiella, Proteus and Yersinia. Members of this family are facultative anaerobes, able to ferment sugars to lactic acid, have nitrate reductase, but lack oxidases. Even though many clinical pathogens are part of the Enterobacteriaceae family, most members of this family are plant pathogens. D. dadantii is a motile, nonsporing, straight rod-shaped cell with rounded ends. Cells range in size from 0.8 to 3.2 μm by 0.5 to 0.8 μm and are surrounded by numerous flagella (peritrichous).
In the natural plant environment, D. dadantii causes plant maladies such as necrosis, blight and “soft rot,” which is a progressive tissue maceration. D. dadantii contains many pectinases that are able to macerate and break down the plant cell wall material. This exposed part of the plant releases nutrients that can facilitate bacterial growth. Commonly infected plants include potato tubers, bulbs of vegetables, and ornamental crops.
Read more about Erwinia Chrysanthemi: Hosts, Symptoms, Disease Cycle, Environment, Management, Importance