Applied and Environmental Microbiology (2009) 75, 1173-1184

Lan Bui Thi Ngoc, Christian Vernière, Philippe Jarne, Sylvain Brisse, Fabien Guérin, Sébastien Boutry, Lionel Gagnevin and Olivier Pruvost (2009)
From local surveys to global surveillance: three high-throughput genotyping methods for epidemiological monitoring of Xanthomonas citri pv. citri pathotypes
Applied and Environmental Microbiology 75 (4), 1173-1184
Abstract: Asiatic citrus canker is a major disease worldwide, and its causal agent, Xanthomonas citri pv. citri, is listed as a quarantine organism in many countries. Analysis of the molecular epidemiology of this bacterium is hindered by a lack of molecular typing techniques suitable for surveillance and outbreak investigation. We report a comparative evaluation of three typing techniques, amplified fragment length polymorphism (AFLP) analysis, insertion sequence ligation-mediated PCR (IS-LM-PCR) typing, and multilocus variable-number tandem-repeat analysis (MLVA), with 234 strains originating from Asia, the likely center of origin of the pathogen, and reference strains of pathotypes A, A*, and A^w, which differ in host range. The typing techniques were congruent in describing the diversity of this strain collection, suggesting that the evolution pattern of the bacterium may be clonal. Based on a hierarchical analysis of molecular variance, the AFLP method best described the genetic variation found among pathotypes whereas MLVA best described the variation found among individual strains from the same countries or groups of neighboring countries. IS-LM-PCR data suggested that the transposition of insertion sequences in the genome of X. citri pv. citri occurs rarely enough not to disturb the phylogenetic signal. This technique may be useful for the global surveillance of non-epidemiologically related strains. Although pathological characteristics of strains could be most often predicted from genotyping data, we report the occurrence in the Indian peninsula of strains genetically related to pathotype A* strains but with a host range similar to that of pathotype A, which makes the classification of this bacterium even more complicated.
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Link to article at publishers website
Database assignments for author(s): Olivier Pruvost, Christian Verniere

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
identification/taxonomy

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Xanthomonas citri