Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 11/19/2018
Publication Date: 12/17/2018
Citation: Burbank, L.P., Ortega, B.C. 2018. Novel amplification targets for rapid detection and differentiation of Xylella fastidiosa subspecies fastidiosa and multiplex in plant and insect tissue. CDFA Pierce's Disease Control Program Research Symposium. p. 134.
Technical Abstract: Several different subspecies of Xylella fastidiosa have been described worldwide, causing disease in a variety of economically important crops. Numerous molecular detection protocols are available for quarantine screening, surveillance, and research applications; but most cannot differentiate between strains or subspecies of the pathogen. In areas such as California where more than one subspecies is present, it is important to be able to determine subspecies affiliation. This study describes quantitative PCR (qPCR) and loop-mediated isothermal amplification assays (LAMP) which can rapidly identify X. fastidiosa isolates belonging to the fastidiosa and multiplex subspecies. The TaqMan qPCR primers described here are used to differentiate X. fastidiosa strains by subspecies in plant and insect tissue in a single reaction, with the inclusion of a general amplification control probe to identify potential false negative samples. Sensitivity of the TaqMan qPCR protocol is between 10^3 and 10^4 cfu/ml concentrations of X. fastidiosa in a variety of sample types. Additionally, LAMP targets were designed for faster detection of X. fastidiosa subspecies fastidiosa and multiplex, which could be modified to use in a field setting. These assays are effective for strain differentiation in artificially and naturally inoculated plant material, and in field-collected insect vectors.