Isolation and genetic characterization of Erwinia amylovora bacteria from Kyrgyzstan

Abstract Fire Blight, an economically relevant disease of
apple, pear, and quince trees that is caused by the Gramnegative
bacterium Erwinia amylovora, was first reported
from Kyrgyzstan in 2008. One decade later, the disease has
spread across the northern part of the country, affecting
fruit orchards mainly in Chuy and Issyk-kul regions. Using
semi-selective cultural media, bacteria have been isolated
from plant material sampled in infested orchards from
different locations in Kyrgyzstan, and 16S rRNA gene
sequence determination together with diagnostic PCR
have been used to identify E. amylovora bacteria among
isolates. The assignment to this taxonomic species has
been corroborated by phylogenetic reconstruction using
multilocus sequence analysis, and a short-sequence repeat (SSR) marker has been employed to estimate genetic
diversity across the isolates. CRISPR analysis has revealed
both a previously unreported CRISPR-2 array pattern and
a close relationship of Kyrgyz E. amylovora isolates to
strains present in Europe and the Middle East. This study
presents the first consistent molecular taxonomic characterization
of E. amylovora bacteria from Kyrgyzstan.