XadA2 Adhesin Decreases Biofilm Formation and Transmission of <i>Xylella fastidiosa</i> subsp. <i>pauca</i>
Mariana Bossi Esteves,
Julia Lopes Nalin,
Karla Kudlawiec,
Raquel Caserta Salviatto,
Tiago de Melo Sales,
Anne Sicard,
Rodrigo Piacentini Paes de Almeida,
Alessandra Alves de Souza,
João Roberto Spotti Lopes
Affiliations
Mariana Bossi Esteves
Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP), Piracicaba, SP 13418-900, Brazil
Julia Lopes Nalin
Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP), Piracicaba, SP 13418-900, Brazil
Karla Kudlawiec
Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP), Piracicaba, SP 13418-900, Brazil
Raquel Caserta Salviatto
Centro de Citricultura “Sylvio Moreira”, Instituto Agronômico, Cordeirópolis, SP 13490-970, Brazil
Tiago de Melo Sales
Instituto Federal do Pará, Castanhal, Pará 68740-970, Brazil
Anne Sicard
Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3114, USA
Rodrigo Piacentini Paes de Almeida
Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3114, USA
Alessandra Alves de Souza
Centro de Citricultura “Sylvio Moreira”, Instituto Agronômico, Cordeirópolis, SP 13490-970, Brazil
João Roberto Spotti Lopes
Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP), Piracicaba, SP 13418-900, Brazil
Xylella fastidiosa is a vector-borne bacterium that causes diseases in many plants of economic interest. The bacterium–vector initial interactions involve bacterial membrane-bound adhesins that mediate cell attachment to the foregut of insect vectors. We investigated the role of the afimbrial adhesin XadA2 in the binding and biofilm formation of X. fastidiosa subsp. pauca to vector surfaces in vitro, as well as its potential to disrupt pathogen transmission. We showed that XadA2 has binding affinity for polysaccharides on sharpshooter hindwings, used as a proxy for the interactions between X. fastidiosa and vectors. When in a medium without carbon sources, the bacterium used wing components, likely chitin, as a source of nutrients and formed a biofilm on the wing surface. There was a significant reduction in X. fastidiosa biofilm formation and cell aggregation on vector wings in competition assays with XadA2 or its specific antibody (anti-XadA2). Finally, pathogen acquisition and transmission to plant were significantly reduced when the vectors acquired X. fastidiosa from an artificial diet supplemented with anti-XadA2. These results show that XadA2 is important in mediating bacterial colonization in the insect and that it could be used as a target for blocking X. fastidiosa transmission.