Fighting fire blight and detecting Salmonella

Typography

The plant disease fire blight, caused by the bacterium Erwinia amylovora, is dreaded by fruit growers. It affects apple and pear trees and other plants in the rosacea family, and if a tree becomes affected it usually has to be cleared and burned.

The plant disease fire blight, caused by the bacterium Erwinia amylovora, is dreaded by fruit growers. It affects apple and pear trees and other plants in the rosacea family, and if a tree becomes affected it usually has to be cleared and burned.

The pathogen that causes fire blight is difficult to control. In exceptional cases, farmers can use the antibiotic streptomycin, but even this cannot prevent the pathogen from disseminating via pollinating insects.

Use the enemy’s enemy

A new control strategy has now been presented by researchers led by ETH professor Martin Loessner: they employed a bacterial virus (bacteriophage) designated Y2 that exclusively infects the fire blight pathogen, and equipped it with additional genes. This allowed them to create a highly effective and specific weapon against the Erwiniabacterium.

The native form of Y2 is a natural Erwinia killer, but it is unable to adequately penetrate the thick slime layer that protects the bacterium. Infact, this carbohydrate slime is very tough and clogs the vascular system of plants, causing the flowers and leaves to wither.

Read more at ETH Zurich

Photo credit: Peggy Greb via Wikimedia Commons