Type of detection:
Type of method:
Lateral Flow Immunochromatography
Description of the test:
The rapid assay Ea AgriStrip is a lateral-flow immunographic test based on an antigenantibody reaction that is initiated by inserting the strip into the sample extract. The sample liquid migrates upwards and red colored lines will become visible within a few minutes. Both test and control lines become visible with positive extracts (containing Erwinia amylovora), whereas negative samples produce only the upper control line. Intense coloration is reached within 10 - 15 min. and the result can be registered. Dried test strips can be kept as permanent records.
Type of sample:
bark; bacterial exudation; leaves; active cankers
Available extraction method:
Sampling on symptomatic wood: Remove the bark layer and scrape with a sharp and disinfected knife small longitudinal pieces of approx. 1 mm thickness at the transition zone between healthy and symptomatic cambium tissue. First transfer 4 ml of extraction buffer with a disposable pipette in an extraction bag, then add 0.2 g of the cambium material. Crush the tissue (e.g. with a rubber hammer) thoroughly on a flat surface to mix the extruded plant sap with the extraction buffer. Then transfer 4 drops (approx. 150 µl) of this extract into a cuvette with a disposable pipette.
Sampling on pear leaves: At the last sampling step transfer 2 drops (approx. 75 µl) of the extract into a cuvette with a disposable pipette and then add 2 drops of extraction buffer and mix well by pipetting up and down.
Sampling of bacterial ooze: First add 4 drops of extraction buffer in a cuvette. Then take a tiny amount of the bacterial exudation by touching with the tip of the disposable pipette and suspend it in the extraction buffer in the cuvette. Do not take more of the ooze than what is necessary to get a slight turbidity of the buffer. A highly excessive bacterial suspension (opaque solution) can interfere with test efficacy.
Available extraction method PDF:
The rapid assay Ea AgriStrip for Erwinia amylovora detection is produced by BIOREBA and has been validated in cooperation with Agroscope, the Swiss centre of excellence for research in the agriculture and food sector. This project was supported by the Innovation Promotion Agency (CTI) of the Swiss government. The rapid assay enables confirmation of the presence of fire blight pathogen on-site and within minutes in pome fruit and related ornamentals and wild plants. Samples are best taken in the transition zone between healthy and symptomatic tissues containing the highest concentration of bacteria. Active cankers and bacterial ooze are also suitable for testing. Asymptomatic flowers, inactive cankers, and roots, however, may not give reliable results due to low bacterial concentration. Although harmless for human, the fire blight causing bacterium Ea is highly contagious and of great concern especially to pome fruit producers. In certain countries, it is regulated as a quarantine pest. Appropriate hygiene/disposal after sampling is critical to prevent spread of this devastating disease, and local phytosanitary regulations must be followed.