Xylella fastidiosa: A MOLECULAR ANALYSIS OF BACTERIAL DISEASE STATUS AT INTERNATIONAL LEVEL

Abstract

Background: Xylella fastidiosa is a bacterium considered native to the American continent, which affects the vascular ducts of the xylem, causing diseases with an economically important cost in plantations. This species is distributed in Asia, America and Europe. The bacteria can be transmitted with the help of vector insects. Objective. The objective of this work was to carry out an analysis of the main theoretical and practical aspects of the X. fastidiosa species and its impact on agriculture. Methodology. The method used was a review of the literature and information available on the bacterium Xylella fastidiosa and its subspecies internationally and nationally. Main findings. The first known syndrome caused by this bacterium was described in 1892 by Newton Barris Pierce, when a strange pathology devastated thousands of hectares of vine in Los Angeles. In Mexico, Pierce's disease was detected in 1980 in vineyards in Baja California Norte and in 1995 in vineyards in Valle de Guadalupe, in the municipality of Ensenada, Baja California. X. fastidiosa entered the genomic era when in the year 2000 the first genome of a bacterium associated with plants, the 9a5c strain of Citrus Variegated Chlorosis, was sequenced. Since the first half of the 1990s, specific PCR primers have been used to identify X. fastidiosa from infected plants. Implications. Six subspecies of Xylella fastidiosa are currently considered: fastidiosa, multiplex, sandyi, tashke, pauca and morus; fastidiosa and pauca specifically affect citrus fruits and the related insect vectors are: Bucephalagonia xanthohis, Diloboterus costalimaik, Acrogonia citrina, Oncometopia facialis, Ferrariana trivittata, Plesiommata corniculata, Homalodisca ignorata, Parathona virescens, Sonesimia groscens and Acrogonia virescens. Once the insect contains the bacteria, at least 200 viable bacteria are enough to infect the target plant. Conclusions. Currently there are still no solutions or established techniques to fully protect plantations, it is important to strengthen surveillance to limit the spread. DNA-based molecular biology is a valuable tool for the detection and characterization of X. fastidiosa.