The opinion from EFSA’s Panel on Plant Health is the last one of three outputs addressing a list of questions from the European Commission on X. fastidiosa in Apulia. In this one the Panel addressed the question of whether different types of X. fastidiosa exist in Apulia, where a disease outbreak is affecting olive trees and other plants.

A single study raised questions that multiple genetic types of X. fastidiosa were present in the Apulian area. However, EFSA’s plant health specialists said that there is currently no evidence to support this hypothesis.

To reach its conclusion, the EFSA’s Panel on Plant Health reviewed the latest scientific literature and analysed DNA sequencing data retrieved from samples collected in the region. All the papers concluded that DNA samples collected from olive trees and other plants belong to the same sequence type, called “ST53”.

For the sequence data analysis, the Panel used a dedicated database established in 2005 and that contains the DNA sequences of nearly 300 X. fastidiosa samples. The Panel highlighted that further studies with larger sample sizes are needed to provide more comprehensive answers on this issue. These should include an analysis of complete X. fastidiosa genome sequencing.