Chronicle of a disease foretold (that advances slowly): The 2001 Spanish situation

Abstract

Fire blight was first detected in Spain in 1995. In the following years the disease was identified in seven out of the seventeen Spanish regions, in the Northeastern and Central parts of the country. Typical symptoms were observed in pears, apples, loquats, quinces and in ornamental hosts susceptible to fire blight. The spatial and temporal distribution of the foci suggest that plant material has probably been responsible of the introduction of Erwinia amylovora in some of the areas. Eradication measures have been taken consisting of intensive surveys, analysis and destruction of diseased trees. These measures have been very effective so far because, in most of the zones, the number of outbreaks have not increased exponentially. Consequently, six years after the first detection, Spain is still considered a protected fire blight country in the European Union, because E. amylovora has only been found in a few areas and has subsequently been eradicated. The characterization of 40 Spanish strains of E. amylovora was performed by conventional bacteriological tests, carbon utilization in miniaturized tests, serology, amplified fragment length polymorphism(AFLP) and macrorestriction fragment length polymorphism of genomic DNA followed by PFGE (MRFLP-PFGE). The obtained data support the hypothesis that E. amylovora has been introduced into Spain by infected plant material.