Publicações

@article{Landa2020,

title = {Emergence of a plant pathogen in europe associated with multiple intercontinental introductions},

author = {Blanca B. Landa and Andreina I. Castillo and Annalisa Giampetruzzi and Alexandra Kahn and Miguel Román-Écija and María Pilar Velasco-Amo and Juan A. Navas-Cortés and Ester Marco-Noales and Silvia Barbé and Eduardo Moralejo and Helvecio D. Coletta-Filho and Pasquale Saldarelli and Maria Saponari and Rodrigo P. P. Almeida},

url = {https://journals.asm.org/doi/10.1128/AEM.01521-19},

doi = {10.1128/AEM.01521-19/SUPPL_FILE/ZAM003209563SD1.XLSX},

issn = {10985336},

year  = {2020},

date = {2020-01-01},

journal = {Applied and Environmental Microbiology},

volume = {86},

issue = {3},

publisher = {American Society for Microbiology},

abstract = {Pathogen introductions have led to numerous disease outbreaks in naive regions of the globe. The plant pathogen Xylella fastidiosa has been associated with various recent epidemics in Europe affecting agricultural crops, such as almond, grapevine, and olive, but also endemic species occurring in natural forest landscapes and ornamental plants. We compared whole-genome sequences of X. fastidiosa subspecies multiplex from America and strains associated with recent outbreaks in southern Europe to infer their likely origins and paths of introduction within and between the two continents. Phylogenetic analyses indicated multiple introductions of X. fastidiosa subspecies multiplex into Italy, Spain, and France, most of which emerged from a clade with limited genetic diversity with a likely origin in California, USA. The limited genetic diversity observed in X. fastidiosa subspecies multiplex strains originating from California is likely due to the clade itself being an introduction from X. fastidiosa subspecies multiplex populations in the southeastern United States, where this subspecies is most likely endemic. Despite the genetic diversity found in some areas in Europe, there was no clear evidence of recombination occurring among introduced X. fastidiosa strains in Europe. Sequence type taxonomy, based on multilocus sequence typing (MLST), was shown, at least in one case, to not lead to monophyletic clades of this pathogen; whole-genome sequence data were more informative in resolving the history of introductions than MLST data. Although additional data are necessary to carefully tease out the paths of these recent dispersal events, our results indicate that whole-genome sequence data should be considered when developing management strategies for X. fastidiosa outbreaks. IMPORTANCE Xylella fastidiosa is an economically important plant-pathogenic bacterium that has emerged as a pathogen of global importance associated with a devastating epidemic in olive trees in Italy associated with X. fastidiosa subspecies pauca and other outbreaks in Europe, such as X. fastidiosa subspecies fastidiosa and X. fastidiosa subspecies multiplex in Spain and X. fastidiosa subspecies multiplex in France. We present evidence of multiple introductions of X. fastidiosa subspecies multiplex, likely from the United States, into Spain, Italy, and France. These introductions illustrate the risks associated with the commercial trade of plant material at global scales and the need to develop effective policy to limit the likelihood of pathogen pollution into naive regions. Our study demonstrates the need to utilize whole-genome sequence data to study X. fastidiosa introductions at outbreak stages, since a limited number of genetic markers does not provide sufficient phylogenetic resolution to determine dispersal paths or relationships among strains that are of biological and quarantine relevance.},

keywords = {Emerging disease, Genomic diversity, Outbreaks, Quarantine, Recombination, Xylella fastidiosa},

pubstate = {published},

tppubtype = {article}

}

@article{Vanhove2019,

title = {Genomic diversity and recombination among Xylella fastidiosa subspecies},

author = {Mathieu Vanhove and Adam C. Retchless and Anne Sicard and Adrien Rieux and Helvecio D. Coletta-Filho and Leonardo De La Fuente and Drake C. Stenger and Rodrigo P. P. Almeida},

url = {https://journals.asm.org/doi/10.1128/AEM.02972-18},

doi = {10.1128/AEM.02972-18/SUPPL_FILE/AEM.02972-18-S0001.PDF},

issn = {10985336},

year  = {2019},

date = {2019-01-01},

journal = {Applied and Environmental Microbiology},

volume = {85},

issue = {13},

pages = {2972-2990},

publisher = {American Society for Microbiology},

abstract = {Xylella fastidiosa is an economically important bacterial plant pathogen. With insights gained from 72 genomes, this study investigated differences among the three main subspecies, which have allopatric origins: X. fastidiosa subsp. fastidiosa, multiplex, and pauca. The origin of recombinogenic X. fastidiosa subsp. morus and sandyi was also assessed. The evolutionary rate of the 622 genes of the species core genome was estimated at the scale of an X. fastidiosa subsp. pauca subclade (7.62×10-7 substitutions per site per year), which was subsequently used to estimate divergence time for the subspecies and introduction events. The study characterized genes present in the accessory genome of each of the three subspecies and investigated the core genome to detect genes potentially under positive selection. Recombination is recognized to be the major driver of diversity in X. fastidiosa, potentially facilitating shifts to novel plant hosts. The relative effect of recombination in comparison to point mutation was calculated (r/m=2.259). Evidence of recombination was uncovered in the core genome alignment; X. fastidiosa subsp. fastidiosa in the United States was less prone to recombination, with an average of 3.22 of the 622 core genes identified as recombining regions, whereas a specific clade of X. fastidiosa subsp. multiplex was found to have on average 9.60 recombining genes, 93.2% of which originated from X. fastidiosa subsp. fastidiosa. Interestingly, for X. fastidiosa subsp. morus, which was initially thought to be the outcome of genome-wide recombination between X. fastidiosa subsp. fastidiosa and X. fastidiosa subsp. multiplex, intersubspecies homologous recombination levels reached 15.30% in the core genome. Finally, there is evidence of X. fastidiosa subsp. pauca strains from citrus containing genetic elements acquired from strains infecting coffee plants as well as genetic elements from both X. fastidiosa subsp. fastidiosa and X. fastidiosa subsp. multiplex. In summary, our data provide new insights into the evolution and epidemiology of this plant pathogen.},

keywords = {Emerging disease, Genomic diversity, Recombination, Xylella fastidiosa},

pubstate = {published},

tppubtype = {article}

}