Antibacterial activity of alkyl gallates against Xanthomonas citri subsp. citri

The plant-pathogenic bacterium Xanthomonas citri subsp. citri is the causal agent of Asiatic citrus canker, a seriousdisease that affects all the cultivars of citrus in subtropical citrus-producing areas worldwide. There is no curative treatment for citrus canker; thus, the eradication of infected plants constitutes the only effective control of the spread ofX. citri subsp. citri. Since the eradication program in the state of São Paulo, Brazil, is under threat, there is a clear risk of X. citri subsp. citri becoming endemic in the main orange-producing area in the world. Here we evaluated the potential use of alkyl gallates to prevent X. citri subsp. citri growth. These esters displayed a potent anti-X. citri subsp. citri activity similar to that of kanamycin (positive control), as evaluated by the resazurin microtiter assay (REMA). Thetreatment of X. citri subsp. citri cells with these compounds induced altered cell morphology, and investigations of the possible intracellular targets using X. citri subsp. citri strains labeled for the septum and centromere pointed to a commontarget involved in chromosome segregation and cell division. Finally, the artificial inoculation of citrus with X. citri subsp. citri cells pretreated with alkyl gallates showed that the bacterium loses the ability to colonize its host, which indicates the potential of these esters to protect citrus plants against X. citri subsp. citri infection. © 2013, American Society for Microbiology.

Bacillus thuringiensis Cry1Ia10 and Vip3Aa protein interactions and their toxicity in Spodoptera spp. (Lepidoptera)

The polyphagous pests belonging to the genus Spodoptera are considered to be among the most important causes of damage and are widely distributed throughout the Americas'. Due to the extensive use of genetically modified plants containing Bacillus thuringiensis genes that code for insecticidal proteins, resistant insects may arise. To prevent the development of resistance, pyramided plants, which express multiple insecticidal proteins that act through distinct mode of actions, can be used. This study analyzed the mechanisms of action for the proteins Cry1Ia10 and Vip3Aa on neonatal Spodoptera frugiperda, Spodoptera albula, Spodoptera eridania and Spodoptera cosmioides larvae. The interactions of these toxins with receptors on the intestinal epithelial membrane were also analyzed by binding biotinylated toxins to brush border membrane vesicles (BBMVs) from the intestines of these insects. A putative receptor of approximately 65. kDa was found by ligand blotting in all of these species. In vitro competition assays using biotinylated proteins have indicated that Vip3Aa and Cry1Ia10 do not compete for the same receptor for S. frugiperda, S. albula and S. cosmioides and that Vip3Aa was more efficient than Cry1Ia10 when tested individually, by bioassays. A synergistic effect of the toxins in S. frugiperda, S. albula and S. cosmioides was observed when they were combined. However, in S. eridania, Cry1Ia10 and Vip3Aa might compete for the same receptor and through bioassays Cry1Ia10 was more efficient than Vip3Aa and showed an antagonistic effect when the proteins were combined. These results suggest that using these genes to develop pyramided plants may not prove effective in preventing the development of resistance in S. eridiana. © 2012 Elsevier Inc.

Polymerase chain reaction assay based on ratA gene allows differentiation between Salmonella enterica subsp. enterica serovar Gallinarum biovars Gallinarum and Pullorum

Salmonella Pullorum and Salmonella Gallinarum are classified as biovars of Salmonella enterica subsp. enterica serovar Gallinarum. These salmonellae are the causative agents of Pullorum disease and fowl typhoid, respectively, and are widely distributed throughout the world. Although many developed countries have eradicated these diseases from commercial poultry, they are still the cause of significant economic loss in developing countries. When serovar Gallinarum is isolated, it is difficult to immediately differentiate between biovars because they are antigenically identical by serotyping. However, they cause distinct diseases with different epidemiology, and therefore it is important to differentiate them. This may be done biochemically but takes 2 to 3 days. In the present study, S. Pullorum and S. Gallinarum whole genomes were compared, and 1 genomic region of difference, which is part of the ratA gene, was chosen as a molecular marker for a polymerase chain reaction assay to differentiate rapidly between these organisms. In all, 26 strains of S. Gallinarum and 17 S. Pullorum strains were tested and successfully differentiated by the assay. © 2013 The Author(s).

Participação da ORF XAC3629 na regulação do operon de resistência a cobre copAB em Xanthomonas citri subsp. citri

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudos da utilização de sangue de abatedouros como substrato fermentativo para produção de Bacillus thuringiensis por fermentação submersa

Pós-graduação em Biotecnologia - IQ

Efeitos da interação e toxicidade das proteínas Cry1 e Vip3Aa de Bacillus thuringiensis, Berliner em Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

Pós-graduação em Microbiologia Agropecuária - FCAV

Efeito de produtos a base de Bacillus thuringiensis Berliner em aspectos biológicos de Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Performance de Trichogramma pretiosum Riley, 1879 e T. exiguum Pinto & Platner, 1978 (Hymenoptera: trichogrammatidae) em ovos de populações de Plutella xylostella (LINNAEUS, 1758) (Lepidoptera: Plutellidae) sob ação de Bacillus thuringiensis Berliner, 1915 (Bacillales: Bacillaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variabilidade populacional de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae) e suscetibilidade a Bacillus thuringiensis Berliner

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Seleção de isolados de Bacillus thuringiensis Berliner em lagartas de Putella xylostella (L.) (Lepdoptera: Plutellidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência da temperatura sobre fisiologia e crescimento de Xanthomonas citri subsp. citri

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Isolamento, caracterização molecular e expressão de um novo gene vip3Aa50 de Bacillus thuringiensis virulento para Anticarsia gemmatalis e Spodoptera frugiperda

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Proteínas Cry1 e Vip3A de Bacillus thuringiensis: sinergismo e efeito sub-letal no controle de Heliothis virescens

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise da expressão dos genes pertencentes aos sistemas secretórios Tipo III e Tipo IV e genes pthAs em Xanthomonas citri subsp. citri sob condições infectante e não infectante

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise por sequências multilocus de Xanthomonas fuscans subsp. aurantifolii

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)