Use of portable real-time PCR for same-day on-site field diagnosis of bacterial diseases

• Author(s): Gaush, P.; Postnikova, E.; Schaad, Norman;
• Abstract: Diagnosing bacterial diseases can be very time consuming. Traditional isolation and pathogenicity tests are very sensitive but require 10-20 days or longer. Serological techniques can reduce the time, but the detection threshold is only 104-105 cfu/ml. Classical PCR is 10 times more sensitive than serology but requires confirmation tests. Real-time PCR does not require confirmation by a Southern blot, but the equipment is very expensive. We have developed real-time PCR assays using the portable Smart Cycler SC System (Cepheid, Sunnyvale, CA) for on-site detection of several bacteria including Acidovorax avenae subsp. citrulli in watermelon, Pseudomonas phaseolicola pv. phaseolicola in beans, Ralstonia solanacearum in potato, and Xylella fastidiosa in grape, citrus, and shade trees. All can be detected in under one hour, including sample preparation. If greater sensitivity is more important than time, samples can be enriched for BIO-PCR in liquid or on solid media.
• Publication Date: Jun 2002
• Journal: Phytopathology