DETECTION OF XYLELLA FASTIDIOSA: VALIDATION AND IMPLEMENTATION OF ROUTINE TESTING METHODS

Accurate and early detection of Xylella fastidiosa (Xf) is a major
challenge due to the wide range of host plants (different matrices/
tissues, rate of host colonization) and the occurrence of symptomless
bacterial infections. The recent establishment of this exotic
plant pathogenic bacterium in the EU territory and the large panel
of EU susceptible host plants increased the need for rapid diagnostic
tools suitable for processing large number of samples and
from different sources. Although, several approaches are currently
available for the detection of Xf in the host plants and vectors, there
is a need for harmonized protocols and user-friendly diagnostic
tests. In this study, we compared the sensitivity and the reliability
of a selected panel of currently available protocols (ELISA, PCR,
qPCR), in comparison with novel approaches based on automatized
diagnostic platform and on DTBIA and LAMP-based assays.
The overall results showed that: (i) although resulting in different
diagnostic sensitivity all the approaches tested were able to detect
the bacterium in samples from symptomless plants; (ii) Real-time
LAMP assay based using crude plant sap can represent a rapid
and reliable screening test; (iii) Real-time quantitative PCR assays
had the higher diagnostic and analytical sensitivity; (iv) the use
of automatized platform allowed to prepare PCR-templates with
high and standardized quality for highly reliable diagnostic results;
(v) DTBIA had the lowest diagnostic sensitivity, yet representing a
useful approach when movement of Xf infected materials is limited
due to the phytosanitary regulations.