TOWARDS THE DEVELOPMENT OF A SEQUENCE-BASED PCR SYSTEM FOR DETECTION AND GENOMIC STUDY OF XYLELLA FASTIDOSA STRAINS IMPORTANT TO CALIFORNIA

• Author(s): Chen, Jianchi; Civerolo, Ed; Kirkpatrick, Bruce; Livingston, Sam;
• Abstract: We report two of our recent efforts for improvement of PCR detection and genomic analysis of Xylella fastidiosa (Xf). We evaluated the use of PCR primers from a hyper-variable locus to monitor diversity within strains of the same pathotype. The pspB (PD1208) locus, encoding a serine protease, was selected and analyzed. It was observed that tandem repeat sequences in pspB locus were highly variable from strain to strain. The biological significance of this hyper-variation is unknown. We also evaluated a simple sample preparation method for template DNA. The pulverized freeze-dried tissue PCR (PFT-PCR) test was compared to the gold standard pathogen isolation method. Our results indicated that PFT-PCR had a high predictive value (90.8%) for true positive samples, but a low predictive value for true negative results (29.7%), indicating that a PFT-PCR result is best suited to confirm the presence of Xf in a sample.
• Publication Date: Nov 2006
• Journal: 2006 Pierce's Disease Research Symposium