Clavibacter in tomato: 30-minute detection test

Clavibacter michiganensis subsp. michiganensis, the causal agent of bacterial canker of tomato, is a devastating disease that can result in crop losses of up to 100% if not quickly identified and managed. For several months, Agdia, Inc. commercializes a rapid and user-friendly DNA test kit, based on their AmplifyRP® XRT platform, for detection of Clavibacter michiganensis subsp. michiganensis (Cmm) in tomato. Agdia’s test for Cmm provides growers and diagnostic laboratories a new and more powerful tool to assist in the diagnosis of this important pathogen.

The test is a real-time isothermal DNA amplification assay that utilizes recombinase polymerase amplification (RPA) technology. RPA facilitates rapid nucleic acid (DNA or RNA) amplification at a single operating temperature of 39°C using crude sample extracts. RPA can provide the same level of sensitivity and specificity as laboratory based PCR (polymerase chain reaction) methods, but offers some clear advantages.

The total assay time is less than 30 minutes, including sample preparation. This is a stark contrast to PCR methods which can take hours or days to complete. PCR analysis must also be completed in a laboratory whereas AmplifyRP XRT can be performed on-site using a battery operated portable fluorometer. Agdia states their new test is capable of detecting concentrations of Cmm bacteria as low as 200 colony forming unit/ml (cfu/ml), which offers greater sensitivity than any other commercially available test kit.

Agdia claims the test is compatible with several commercially available fluorometers but recommends the AmpliFire® manufactured by Douglas Scientific. The AmpliFire is battery operated and has a small footprint, making it possible to test in remote locations. Setup is simple because all the assay parameters are loaded into the AmpliFire using a barcode that is affixed to the tests packaging. It also has a large, intuitive, touch screen interface that is used to initiate reactions and view results. 

Source: Agdia Press Release, www.agdia.com